├── LICENSE
├── README.md
├── my-alternatives-debian
└── my-alternatives-redhat


/LICENSE:
--------------------------------------------------------------------------------
 1 | MIT License
 2 | 
 3 | Copyright (c) 2021 TekWizely
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | # My-Alternatives<br/>(hacking update-alternatives to make local changes)
  2 | [![MIT license](https://img.shields.io/badge/License-MIT-green.svg)](https://github.com/tekwizely/pre-commit-golang/blob/master/LICENSE)
  3 | 
  4 | My-Alternatives is a light-weight wrapper over _update-alternatives_, offering user-level customizations.
  5 | 
  6 | Supports _Debian_, _SUSE_<sup>*</sup>, and _RedHat_
  7 | 
  8 | <sub>* for suse support, use the debian version</sub>
  9 | 
 10 | -----------------------
 11 | ### Easy to Get Started
 12 | 
 13 | With my-alternatives, configuring custom alternatives is as easy as:
 14 | 
 15 | _home configuration example_
 16 | ```shell
 17 |     # initialize my-alternatives
 18 |     # note: place this in your .profile
 19 |     $ eval "$( my-alternatives init )"
 20 | 
 21 |     # customize an alternative
 22 |     $ my-alternatives select <name>
 23 | ```
 24 | 
 25 | Your selections will be saved into your `HOME` configuration, and made active in any login shell that performs the initialization routine.
 26 | 
 27 | **NOTE:** You can save the initialization routine in your `.profile`
 28 | 
 29 | ### Per-Shell Configuration
 30 | 
 31 | If you want to make a temporary change that only modifies your current shell session, you can initialize a `TEMP` configuration:
 32 | 
 33 | _temp configuration example_
 34 | ```shell
 35 |     # initialize a temporary configuration
 36 |     # note: your HOME configuration must already be initialized
 37 |     $ my-alternatives init-tmp
 38 | 
 39 |     # customize an alternative for just the current shell
 40 |     $ my-alternatives select <name>
 41 | ```
 42 | 
 43 | ### Auto-Import
 44 | 
 45 | The first time you `select` an alternative, my-alternatives automatically imports the alternative group into your configuration.
 46 | 
 47 | When the `HOME` configuration is the active configuration, my-alternatives imports the group from the system-level configuration.
 48 | 
 49 | When a `TEMP` configuration is active, my-alternatives first tries to import from your `HOME` configuration, falling back onto the system-level configuration if the group is not present.
 50 | 
 51 | ### Manual Import
 52 | 
 53 | If you want to import an alternative group into your active configuration without selecting an alternative, you can use the `import` command:
 54 | 
 55 | _import example_
 56 | ```shell
 57 | $ my-alternatives import <name>
 58 | ```
 59 | -----------
 60 | ## Commands
 61 | 
 62 | Below are tables of the available commands for each supported OS
 63 | 
 64 | ### Debian / SUSE
 65 | 
 66 | **NOTE:** _SUSE_ uses a [rebranded](https://build.opensuse.org/package/view_file/openSUSE:Leap:15.2/update-alternatives/update-alternatives-suse.patch?expand=1) version of _Debian's_ udpate-alternatives.
 67 | 
 68 | Until such time as the feature set of the two versions diverges, this project will **just** maintain the _Debian_ vesion.
 69 | 
 70 | #### My-Alternatives-Debian Commands
 71 | 
 72 | Below is the list of custom commands that _my-alternatives-debian_ implements:
 73 | 
 74 | | Command            | Description 
 75 | |--------------------|------------
 76 | | `init`, `shellenv` | Prepare the current shell session for user-level alternatives.
 77 | | `init-tmp`, `tmp`  | Configure the current shell session for temporary (short-lived) changes.
 78 | | `rm-tmp`           | Remove the temporary configuration from the current shell session, making the `HOME` configuration active.
 79 | | `select`, `config` | Select the active alternative for a group.  This is equivalent to `update-alternatives --config` with the adition of the auto-import logic.
 80 | | `import`           | Import an alternative group into the current configuration.
 81 | | `add`              | Add an alternative to a group within the current configuration.  This is equivalent to `update-alternatives --install` but has _slightly_ different syntax.  see `my-alternatives help add` for details.
 82 | | `version`          | Display my-alternatives version number.
 83 | 
 84 | **NOTE:** See `my-alternatives help <command>` to learn about a specific command, including additional options.
 85 | 
 86 | #### Debian Update-Alternatives Commands
 87 | 
 88 | Below is the list of commands that are implemented as pass-through to the related _Debian_ update-alternatives command:
 89 | 
 90 | | My-Alternatives Command | Update-Alternatives Command
 91 | |-------------------------|----------------------------
 92 | | `select`, `config`      | `--config`
 93 | | `select-all`, `--config-all` | `--all`
 94 | | `rm-alt`                | `--remove`
 95 | | `rm-group`, `rm-grp`    | `--remove-all`
 96 | | `query`                 | `--query`
 97 | | `display`               | `--display`
 98 | | `list`                  | `--list`
 99 | | `set`                   | `--set`
100 | | `auto`                  | `--auto`
101 | | `get-selections`        | `--get-selections`
102 | | `set-selections`        | `--set-selections`
103 | | `ua-help`               | `--help`
104 | | `ua-version`            | `--version` 
105 | 
106 | My-Alternatives will set the `--admindir` and `--altdir` options to point to your active configuration.
107 | 
108 | All additional command-line options are passed-through, unmodified.
109 | 
110 | **NOTE:** See `update-alternatives --help` or `man update-alternatives` to learn more about the various commands and their options.
111 | 
112 | ### RedHat
113 | 
114 | #### hacking The system
115 | 
116 | _RedHat_ has its own implementation of update-alternatives, which is slightly different from the _Debian_ version.
117 | 
118 | One **major** difference is that it does NOT support the `--query` option, meaning that there's no means of determining an anternative's full configuraiton using _just_ the tool's public API.
119 | 
120 | In order to support this version, we have to use knowledge of the system's _private_ API.  Namely:
121 | 
122 |  * Defaulting the "admin" directory to `/var/lib/alternatives`
123 |  * Assuming the name and format of files in the admin directory
124 |  * Defaulting the "alt" directory to `/etc/alternatives`
125 |  * Assuming the name and nature of files in the alt directory
126 | 
127 | #### My-Alternatives-RedHat Commands
128 | 
129 | Below is the list of custom commands that _my-alternatives-redhat_ implements:
130 | 
131 | | Command            | Description
132 | |--------------------|------------
133 | | `init`, `shellenv` | Prepare the current shell session for user-level alternatives.
134 | | `init-tmp`, `tmp`  | Configure the current shell session for temporary (short-lived) changes.
135 | | `rm-tmp`           | Remove the temporary configuration from the current shell session, making the `HOME` configuration active.
136 | | `select`, `config` | Select the active alternative for a group.  This is equivalent to `update-alternatives --config` with the adition of the auto-import logic.
137 | | `import`           | Import an alternative group into the current configuration.
138 | | `add`              | Add an alternative to a group within the current configuration.  This is equivalent to `update-alternatives --install` but has _slightly_ different syntax.  see `my-alternatives help add` for details.
139 | | `add-child`        | Add an child to an existing alternative for a group within the current configuration.  This is equivalent to `update-alternatives --add-slave` but has _slightly_ different syntax.  see `my-alternatives help add-child` for details.
140 | | `version`          | Display my-alternatives version number.
141 | 
142 | **NOTE:** See `my-alternatives help <command>` to learn about a specific command, including additional options.
143 | 
144 | #### RedHat Update-Alternatives Commands
145 | 
146 | Below is the list of commands that are implemented as pass-through to the related _RedHat_ update-alternatives command:
147 | 
148 | | My-Alternatives Command | Update-Alternatives Command
149 | |-------------------------|----------------------------
150 | | `select`, `config`      | `--config`
151 | | `add-child`             | `--add-slave`
152 | | `rm-alt`                | `--remove`
153 | | `rm-group`, `rm-grp`    | `--remove-all`
154 | | `rm-child`              | `--remove-slave`
155 | | `display`               | `--display`
156 | | `list`                  | `--list`
157 | | `set`                   | `--set`
158 | | `auto`                  | `--auto`
159 | | `ua-help`               | `--help`
160 | | `ua-version`            | `--version`
161 | 
162 | My-Alternatives will set the `--admindir` and `--altdir` options to point to your active configuration.
163 | 
164 | All additional command-line options are passed-through, unmodified.
165 | 
166 | **NOTE:** See `update-alternatives --help` or `man update-alternatives` to learn more about the various commands and their options.
167 | 
168 | ### Invoking Update-Alternatives Directly
169 | 
170 | If you need to pass a specific command to update-alternatives, you can do so using the `ua` command:
171 | 
172 | _invoke update-alternatives directly_
173 | ```shell
174 | $ my-alternatives ua --display pager
175 | ```
176 | 
177 | My-Alternatives will set the `--admindir` and `--altdir` options to point to your active configuration.
178 | 
179 | All additional command-line options are passed-through, unmodified.
180 | 
181 | **NOTE:** See `update-alternatives --help` or `man update-alternatives` to learn more about available commands and their options.
182 | 
183 | -------------
184 | ## Installing
185 | 
186 | ### Releases
187 | 
188 | See the [Releases](https://github.com/TekWizely/my-alternatives/releases) page for downloadable archives of versioned releases.
189 | 
190 | ### Git
191 | 
192 | ```
193 | git clone git://github.com/TekWizely/my-alternatives.git
194 | ```
195 | 
196 | ### Renaming the Scripts
197 | 
198 | Depending on how you acquire the files, the scripts may be named by their OS flavor, i.e:
199 |  * Debian : `my-alternatives-debian`
200 |  * RedHat : `my-alternatives-redhat`
201 | 
202 | Feel free to rename them as desired.  Personally, I rename the script **AND** set up a few convenient aliases:
203 | ```shell
204 | $ cp my-alternatives-debian ~/bin/my-alternatives
205 | $ alias ma="my-alternatives"
206 | $ alias mua="my-alternatives ua"
207 | ```
208 | 
209 | ---------------
210 | ## Contributing
211 | 
212 | To contribute to My-Alternatives, follow these steps:
213 | 
214 | 1. Fork this repository.
215 | 2. Create a branch: `git checkout -b <branch_name>`.
216 | 3. Make your changes and commit them: `git commit -m '<commit_message>'`
217 | 4. Push to the original branch: `git push origin <project_name>/<location>`
218 | 5. Create the pull request.
219 | 
220 | Alternatively see the GitHub documentation on [creating a pull request](https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/creating-a-pull-request).
221 | 
222 | ----------
223 | ## Contact
224 | 
225 | If you want to contact me you can reach me at TekWizely@gmail.com.
226 | 
227 | ----------
228 | ## License
229 | 
230 | The `tekwizely/my-alternatives` project is released under the [MIT](https://opensource.org/licenses/MIT) License.  See `LICENSE` file.
231 | 
232 | ----------------
233 | ##### Misc Notes
234 | 
235 | As of `v0.7.0`, my-alternatives has been split (and renamed) into two scripts: `my-alternatives-debian` and `my-alternatives-redhat`. 
236 | 
237 | As of `v0.6.0`, my-alternatives is a complete re-write.  As much as possible, commands are implemented as pass-through to _update-alternatives_, pointing to your active configuration.
238 | 
239 | My-Alternatives does not require _root / sudo_ privileges to use, as it creates and maintains user-owned configuration directories.
240 | 
241 | **CAVEATS:**
242 | - Written in _Bash_
243 | - Requires the following system tools:
244 |   - `update-alternatives`
245 |   - `readlink` (redhat version)
246 |   - `mktemp` (debian version)
247 |   - `umask`
248 |   - `dirname`
249 |   - `basename`
250 |   - `manpath` _(optional)_
251 | - Utilizes tmp files / directories
252 |   - Sets `umask 077` for safety
253 | - Tested on:
254 |   - Ubuntu
255 |     - `Ubuntu 20.04.3 LTS`
256 |     - `Debian update-alternatives version 1.19.7.`
257 |     - `Bash 5.0.17(1)-release`
258 |   - openSUSE
259 |     - `openSUSE Leap 15.3`
260 |     - `SUSE update-alternatives version 1.19.0.4.`
261 |     - `Bash 4.4.23(1)-release`
262 |   - CentOS
263 |     - `CentOS Linux release 8.4.2105`
264 |     - `alternatives version 1.13`
265 |     - `GNU bash, version 4.4.19(1)-release`
266 | 


--------------------------------------------------------------------------------
/my-alternatives-debian:
--------------------------------------------------------------------------------
   1 | #!/usr/bin/env bash
   2 | #######################################################################
   3 | # SPDX-License-Identifier: MIT
   4 | # Copyright (c) 2021 TekWizely & co-authors
   5 | #
   6 | # Use of this source code is governed by the MIT license.
   7 | # See the accompanying LICENSE file, if present, or visit:
   8 | #   https://opensource.org/licenses/MIT
   9 | #######################################################################
  10 | VERSION="v0.7.0-debian"
  11 | 
  12 | set -Eeuo pipefail
  13 | umask 077 # We use tmp files. Try to protect the user
  14 | 
  15 | function usage() {
  16 | 	# Need to escape $ and \
  17 | 	cat <<-USAGE
  18 | 		my-alternatives (${VERSION})
  19 | 
  20 | 		  a wrapper for update-alternatives to enable user-level configuration.
  21 | 		  also supports temporary (per-shell) changes.
  22 | 
  23 | 		usage:
  24 | 
  25 | 		  eval "\$( my-alternatives <init | shellenv> [--shell <shell>] [alt_home] )"
  26 | 		    prepare the current shell session for user-level alternatives
  27 | 		    NOTE: place this in your .profile
  28 | 		  my-alternatives <init-tmp | tmp> [tmp_dir]
  29 | 		    configure the current shell session for temporary (short-lived) changes
  30 | 		  my-alternatives <rm-tmp | rmtmp>
  31 | 		    remove the temporary configuration from the current shell session
  32 | 		  my-alternatives <command> [option ...]
  33 | 		    invoke a command
  34 | 		  my-alternatives help <command>
  35 | 		    learn more about a specific command
  36 | 
  37 | 		custom commands:
  38 | 
  39 | 		  import <name>
  40 | 		    import the alternative group <name> into the current configuration
  41 | 		    when the default configuration is active, imports from system-level alternatives
  42 | 		    when a tmporary configuration is active, first tries the default configuration, then system-level alternatives
  43 | 		  add <name> ...
  44 | 		    add an alternative to the group <name> within the current configuration
  45 | 		    see 'help add' for usage details
  46 | 		  select | config <name>
  47 | 		    select the active alternative for group <name>
  48 | 		    will first invoke 'import <name>' if the group is not already available in the current configuration
  49 | 		  version
  50 | 		    display my-alternatives version number
  51 | 
  52 | 		renamed pass-through commands:
  53 | 
  54 | 		  select-all | config-all
  55 | 		    invoke 'update-alternatives --all'
  56 | 		  rm-alt | rmalt
  57 | 		    invoke 'update-alternatives --remove'
  58 | 		  rm-group | rmgrp
  59 | 		    invoke 'update-alternatives --remove-all'
  60 | 
  61 | 		    these have been renamed to reduce ambiguity
  62 | 
  63 | 		same-name pass-through commands:
  64 | 
  65 | 		  query | display | list | set | auto | get-selections | set-selections
  66 | 
  67 | 		    invoke 'update-alternatives --<command>'
  68 | 
  69 | 		update-alternatives helper commands:
  70 | 
  71 | 		  ua [option ...]
  72 | 		    invoke 'update-alternatives [option ...]' pointing to the currently-configured alternatives
  73 | 		  ua-help
  74 | 		    invoke 'update-alternatives --help'
  75 | 		  ua-version
  76 | 		    invoke 'update-alternatives --version'
  77 | 
  78 | 	USAGE
  79 | 	exit 2
  80 | }
  81 | 
  82 | function version() {
  83 | 	printf "%s\n" "${VERSION}"
  84 | }
  85 | 
  86 | function main() {
  87 | 
  88 | 	case "${1:-}" in
  89 | 		-h | --help)
  90 | 			usage
  91 | 			;;
  92 | 		help)
  93 | 			shift
  94 | 			case "${1:-}" in
  95 | 				init)
  96 | 					help_init
  97 | 					;;
  98 | 				shellenv) # alias
  99 | 					help_alias "init" "$1"
 100 | 					;;
 101 | 				init-tmp)
 102 | 					help_init_tmp
 103 | 					;;
 104 | 				init-temp | tmp | temp) # aliases
 105 | 					help_alias "init-tmp" "$1"
 106 | 					;;
 107 | 				rm-tmp)
 108 | 					help_rm_tmp
 109 | 					;;
 110 | 				rm-temp | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp) # aliases
 111 | 					help_alias "rm-tmp" "$1"
 112 | 					;;
 113 | 				import)
 114 | 					help_import
 115 | 					;;
 116 | 				add)
 117 | 					help_add
 118 | 					;;
 119 | 				select)
 120 | 					help_select
 121 | 					;;
 122 | 				config) # alias
 123 | 					help_alias "select" "$1"
 124 | 					;;
 125 | 				version)
 126 | 					version
 127 | 					;;
 128 | 				#
 129 | 				# renamed update-alternatives pass-through
 130 | 				#
 131 | 				select-all | config-all)
 132 | 					help_passthrough "all" "$1"
 133 | 					;;
 134 | 				rm-alt | rmalt | remove-alt | removealt)
 135 | 					help_passthrough "remove" "$1"
 136 | 					;;
 137 | 				rm-group | rmgroup | rm-grp | rmgrp | remove-group | removegroup | remove-grp | removegrp)
 138 | 					help_passthrough "remove-all" "$1"
 139 | 					;;
 140 | 				#
 141 | 				# update-alternatives pass-through
 142 | 				#
 143 | 				query | display | list | set | auto | get-selections | set-selections)
 144 | 					help_passthrough "$1"
 145 | 					;;
 146 | 				#
 147 | 				# update-alternatives helpers
 148 | 				#
 149 | 				ua)
 150 | 					help_update_alternatives
 151 | 					;;
 152 | 				ua-help)
 153 | 					help_update_alternatives_help
 154 | 					;;
 155 | 				ua-version)
 156 | 					help_update_alternatives_version
 157 | 					;;
 158 | 				*)
 159 | 					if [ -z "${1:-}" ]; then
 160 | 						printf "usage: help <command>\n" >&2
 161 | 					else
 162 | 						printf "error: unrecognized command: %s\n" "${1}" >&2
 163 | 					fi
 164 | 					printf "\nsee 'my-alternatives --help' for list of commands\n" >&2
 165 | 					exit 2
 166 | 					;;
 167 | 			esac
 168 | 			;;
 169 | 		init | shellenv)
 170 | 			shift
 171 | 			do_init "$@"
 172 | 			;;
 173 | 		init-tmp | init-temp | tmp | temp)
 174 | 			shift
 175 | 			do_init_tmp "$@"
 176 | 			;;
 177 | 		rm-tmp | rm-temp | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp)
 178 | 			shift
 179 | 			do_rm_tmp "$@"
 180 | 			;;
 181 | 		import)
 182 | 			shift
 183 | 			do_import "$@"
 184 | 			;;
 185 | 		add)
 186 | 			shift
 187 | 			do_add "$@"
 188 | 			;;
 189 | 		select | config)
 190 | 			shift
 191 | 			do_select "$@"
 192 | 			;;
 193 | 		version)
 194 | 			version
 195 | 			;;
 196 | 		#
 197 | 		# renamed update-alternatives pass-through
 198 | 		#
 199 | 		select-all | config-all)
 200 | 			shift
 201 | 			do_update_alternatives "--all" "$@"
 202 | 			;;
 203 | 		rm-alt | rmalt | remove-alt | removealt)
 204 | 			shift
 205 | 			do_update_alternatives "--remove" "$@"
 206 | 			;;
 207 | 		rm-group | rmgroup | rm-grp | rmgrp | remove-group | removegroup | remove-grp | removegrp)
 208 | 			shift
 209 | 			do_update_alternatives "--remove-all" "$@"
 210 | 			;;
 211 | 		#
 212 | 		# update-alternatives pass-through
 213 | 		#
 214 | 		query | display | list | set | auto | get-selections | set-selections)
 215 | 			local cmd="${1}"
 216 | 			shift
 217 | 			do_update_alternatives "--${cmd}" "$@"
 218 | 			;;
 219 | 		#
 220 | 		# update-alternatives helpers
 221 | 		#
 222 | 		ua)
 223 | 			shift
 224 | 			do_update_alternatives "$@"
 225 | 			;;
 226 | 		ua-help)
 227 | 			shift
 228 | 			command update-alternatives --help "$@"
 229 | 			;;
 230 | 		ua-version)
 231 | 			shift
 232 | 			command update-alternatives --version "$@"
 233 | 			;;
 234 | 		*)
 235 | 			if [ -z "${1:-}" ]; then
 236 | 				printf "usage: my-alternatives <command> [option ...]\n" >&2
 237 | 			else
 238 | 				printf "error: unrecognized command: %s\n" "${1}" >&2
 239 | 			fi
 240 | 			printf "\nsee 'my-alternatives --help' for list of commands\n" >&2
 241 | 			exit 2
 242 | 			;;
 243 | 	esac
 244 | }
 245 | 
 246 | function help_init() {
 247 | 	cat <<-'USAGE'
 248 | 		usage: eval "$( my-alternatives <init | shellenv> [--shell <shell>] [alt_home] )"
 249 | 
 250 | 		  prepares the current shell session for user-level alternatives.
 251 | 
 252 | 		  if [alt_home] is provided, it will be configured as MY_ALTS_HOME
 253 | 
 254 | 		  when [alt_home] is NOT provided, the following logic will be used determine MY_ALTS_HOME:
 255 | 
 256 | 		    * check if $MY_ALTS_HOME already defined
 257 | 		    * check $XDG_CONFIG_HOME. if present, use $XDG_CONFIG_HOME/my-alternatives
 258 | 		    * finally default to ~/.config/my-alternatives
 259 | 
 260 | 		  when [--shell <shell>] is NOT provided, checks $SHELL.
 261 | 
 262 | 		  NOTE: Currently only 'bash' is supported.
 263 | 
 264 | 		  creates the MY_ALTS_HOME directory and required sub-directories if they don't already exist.
 265 | 
 266 | 		  finally, configures PATH and MANPATH.
 267 | 
 268 | 		example:
 269 | 
 270 | 		  # prepare shell with default MY_ALTS_HOME logic
 271 | 		  # NOTE: you can place this in your .profile
 272 | 		  $ eval "$( command my-alternatives init )"
 273 | 
 274 | 		  # <ALT_HOME> = ~/.config/my-alternatives
 275 | 		  export MY_ALTS_HOME="<ALT_HOME>"
 276 | 		  export PATH="<ALT_HOME>/bin${PATH:+:$PATH}"
 277 | 		  export MANPATH="<ALT_HOME>/man:${MANPATH:-}"
 278 | 
 279 | 		more info:
 280 | 
 281 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 282 | 
 283 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 284 | 
 285 | 	USAGE
 286 | 	exit 2
 287 | }
 288 | 
 289 | function do_init() {
 290 | 	local alt_home shell
 291 | 	while (($#)); do
 292 | 		case "${1}" in
 293 | 			--shell)
 294 | 				if [ -z "${2:-}" ]; then
 295 | 					printf "my-alternatives: error: no value provided for --shell option. see 'my-alternatives help init' for usage\n" >&2
 296 | 					exit 2
 297 | 				fi
 298 | 				# basename as a courtesy in case they use $SHELL/etc
 299 | 				#
 300 | 				shell="$(basename "${2}")"
 301 | 				shift 2
 302 | 				;;
 303 | 			*)
 304 | 				# If alt_home already defined
 305 | 				#
 306 | 				if [ -n "${alt_home:-}" ]; then
 307 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help init' for usage\n" "${1}" >&2
 308 | 					exit 2
 309 | 				fi
 310 | 				alt_home="${1}"
 311 | 				shift
 312 | 				;;
 313 | 		esac
 314 | 	done
 315 | 	# If --shell not provided, check $SHELL
 316 | 	#
 317 | 	if [ -z "${shell:-}" ]; then
 318 | 		shell="$(basename "${SHELL:-}")"
 319 | 		if [ -z "${shell}" ]; then
 320 | 			printf "my-alternatives: error: Unable to determine shell.  see 'my-alternatives help init' for usage\n" >&2
 321 | 			exit 2
 322 | 		fi
 323 | 	fi
 324 | 	# Confirm shell supported
 325 | 	#
 326 | 	if [[ "${shell}" != "bash" ]]; then
 327 | 		printf "my-alternatives: error: unrecognized shell: %s.  see 'my-alternatives help init' for usage\n" "${shell}" >&2
 328 | 		exit 2
 329 | 	fi
 330 | 	#
 331 | 	# set from specified values or default logic
 332 | 	#
 333 | 	MY_ALTS_HOME="${alt_home:-${MY_ALTS_HOME:-${XDG_CONFIG_HOME:-${HOME:?}/.config}/my-alternatives}}"
 334 | 	# print assignments seperately as I don't want to escape ALL the other $ :)
 335 | 	#
 336 | 	printf '_MY_ALTS_HOME="%s"\n' "${MY_ALTS_HOME:?}"
 337 | 	# path clean up adapted from: https://stackoverflow.com/a/2108540/1822537
 338 | 	#
 339 | 	cat <<-'INIT'
 340 | 		if [ -n "${_MY_ALTS_HOME}:-" ] && command mkdir -p -- "${_MY_ALTS_HOME}"; then
 341 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/bin"
 342 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/man"
 343 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/man/man"{1..9}
 344 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/admin"
 345 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/alts"
 346 | 		    # clean up PATH and add to front
 347 | 		    PATH=":${PATH:-}:"
 348 | 		    PATH="${PATH/":${_MY_ALTS_HOME}/bin:"/:}"
 349 | 		    PATH="${PATH%:}"
 350 | 		    PATH="${PATH#:}"
 351 | 		    PATH="${_MY_ALTS_HOME}/bin${PATH:+:$PATH}"
 352 | 		    # clean up MANPATH and add to front
 353 | 		    MANPATH=":${MANPATH:-}:"
 354 | 		    MANPATH="${MANPATH/":${_MY_ALTS_HOME}/man:"/:}"
 355 | 		    MANPATH="${MANPATH%:}"
 356 | 		    MANPATH="${MANPATH#:}"
 357 | 		    MANPATH="${_MY_ALTS_HOME}/man:${MANPATH:-}"
 358 | 		    # add helper function
 359 | 		    my-alternatives() {
 360 | 		        case "${1:-}" in
 361 | 		            # some commands require eval
 362 | 		            init     | shellenv  | \
 363 | 		            init-tmp | init-temp | tmp   | temp   | \
 364 | 		            rm-tmp   | rm-temp   | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp)
 365 | 		                eval "$( command my-alternatives "$@" )"
 366 | 		                ;;
 367 | 		            *)
 368 | 		            command my-alternatives "$@"
 369 | 		                ;;
 370 | 		        esac
 371 | 		    }
 372 | 		    # finally, export variables
 373 | 		    command export MY_ALTS_HOME="${_MY_ALTS_HOME}"
 374 | 		fi
 375 | 		command unset _MY_ALTS_HOME
 376 | 	INIT
 377 | }
 378 | 
 379 | function help_init_tmp() {
 380 | 	cat <<-'USAGE'
 381 | 		usage: my-alternatives <init-tmp | tmp> [tmp_dir]
 382 | 
 383 | 		  configures the current shell session for temporary (short-lived) changes.
 384 | 
 385 | 		  if [tmp_dir] is provided, it will be configured as MY_ALTS_TMP
 386 | 
 387 | 		  when [tmp_dir] is NOT provided, the following logic will be used determine MY_ALTS_TMP:
 388 | 
 389 | 		    * check if $MY_ALTS_TMP already defined
 390 | 		    * check XDG_CACHE_HOME. if present, use XDG_CACHE_HOME/my-alternatives/<RANDOM>
 391 | 		    * finally default to ~/.config/my-alternatives/<RANDOM>
 392 | 
 393 | 		  creates the MY_ALTS_TMP directory and required sub-directories if they don't already exist.
 394 | 
 395 | 		  finally, configures PATH and MANPATH.
 396 | 
 397 | 		example:
 398 | 
 399 | 		  $ my-alternatives init-tmp
 400 | 
 401 | 		  # <ALT_TMP> = ~/.config/my-alternatives/abcd123
 402 | 		  export MY_ALTS_TMP="<ALT_TMP>"
 403 | 		  export PATH="<ALT_TMP>/bin${PATH:+:$PATH}"
 404 | 		  export MANPATH="<ALT_TMP>/man:${MANPATH:-}"
 405 | 
 406 | 		more info:
 407 | 
 408 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 409 | 
 410 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 411 | 
 412 | 	USAGE
 413 | 	exit 2
 414 | }
 415 | 
 416 | function do_init_tmp() {
 417 | 	# Ensure alt_home configured
 418 | 	#
 419 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 420 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 421 | 		exit 2
 422 | 	fi
 423 | 	local alt_tmp
 424 | 	while (($#)); do
 425 | 		case "${1}" in
 426 | 			*)
 427 | 				# If alt_root already defined
 428 | 				#
 429 | 				if [ -n "${alt_tmp:-}" ]; then
 430 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help init-tmp' for usage\n" "${1}" >&2
 431 | 					exit 2
 432 | 				fi
 433 | 				alt_tmp="${1}"
 434 | 				shift
 435 | 				;;
 436 | 		esac
 437 | 	done
 438 | 	# create temp folder if no alt_tmp or MY_ALTS_TMP given
 439 | 	#
 440 | 	MY_ALTS_TMP="${alt_tmp:-${MY_ALTS_TMP:-}}"
 441 | 	if [ -z "${MY_ALTS_TMP}" ]; then
 442 | 		while :; do
 443 | 			MY_ALTS_TMP="${XDG_CACHE_HOME:-"${HOME:?}/.cache"}/my-alternatives/${RANDOM}${RANDOM}"
 444 | 			[ -d "${MY_ALTS_TMP}" ] || break
 445 | 		done
 446 | 	fi
 447 | 	# print assignment seperately as I don't want to escape ALL the other $ :)
 448 | 	#
 449 | 	printf '_MY_ALTS_TMP="%s"\n' "${MY_ALTS_TMP:?}"
 450 | 	cat <<-'TMP'
 451 | 		if [ -n "${_MY_ALTS_TMP}:-" ] && command mkdir -p -- "${_MY_ALTS_TMP}"; then
 452 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/bin"
 453 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/man"
 454 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/man/man"{1..9}
 455 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/admin"
 456 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/alts"
 457 | 		    # clean up PATH and add to front
 458 | 		    PATH=":${PATH:-}:"
 459 | 		    PATH="${PATH/":${_MY_ALTS_TMP}/bin:"/:}"
 460 | 		    PATH="${PATH%:}"
 461 | 		    PATH="${PATH#:}"
 462 | 		    PATH="${_MY_ALTS_TMP}/bin${PATH:+:$PATH}"
 463 | 		    # clean up MANPATH and add to front
 464 | 		    MANPATH=":${MANPATH:-}:"
 465 | 		    MANPATH="${MANPATH/":${_MY_ALTS_TMP}/man:"/:}"
 466 | 		    MANPATH="${MANPATH%:}"
 467 | 		    MANPATH="${MANPATH#:}"
 468 | 		    MANPATH="${_MY_ALTS_TMP}/man:${MANPATH:-}"
 469 | 		    # finally, export tmp variable
 470 | 		    command export MY_ALTS_TMP="${_MY_ALTS_TMP}"
 471 | 		fi
 472 | 		command unset _MY_ALTS_TMP
 473 | 	TMP
 474 | }
 475 | 
 476 | function help_rm_tmp() {
 477 | 	cat <<-'USAGE'
 478 | 		usage: my-alternatives rm-tmp
 479 | 
 480 | 		  removes the temporary configuration from the current shell session.
 481 | 
 482 | 		  restores the curent session to the default user-level alternatives.
 483 | 
 484 | 		  removes the temporary directory referenced by MY_ALTS_TMP
 485 | 
 486 | 		  removes MY_ALTS_TMP from both PATH and MANPATH
 487 | 
 488 | 		  finall, unsets the MY_ALTS_TMP variable
 489 | 
 490 | 		more info:
 491 | 
 492 | 		  see 'my-alternatives --help' to learn more about creating a temporary configuration.
 493 | 
 494 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 495 | 
 496 | 	USAGE
 497 | 	exit 2
 498 | }
 499 | 
 500 | function do_rm_tmp() {
 501 | 	# Ensure alt_home configured
 502 | 	#
 503 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 504 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 505 | 		exit 2
 506 | 	fi
 507 | 	# No further arguments expected
 508 | 	#
 509 | 	if [[ $# -gt 0 ]]; then
 510 | 		printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help rm-tmp' for usage\n" "${1}" >&2
 511 | 		exit 2
 512 | 	fi
 513 | 	cat <<-'RMTMP'
 514 | 		if [ -n "${MY_ALTS_TMP:-}" ]; then
 515 | 		    # clean up temp dir
 516 | 		    if [ -d "${MY_ALTS_TMP}" ]; then
 517 | 		        command rm -rf "${MY_ALTS_TMP}/"
 518 | 		    fi
 519 | 		    # clean up PATH
 520 | 		    PATH=":${PATH:-}:"
 521 | 		    PATH="${PATH/":${MY_ALTS_TMP}/bin:"/:}"
 522 | 		    PATH="${PATH%:}"
 523 | 		    PATH="${PATH#:}"
 524 | 		    # clean up MANPATH
 525 | 		    MANPATH=":${MANPATH:-}:"
 526 | 		    MANPATH="${MANPATH/":${MY_ALTS_TMP}/man:"/:}"
 527 | 		    MANPATH="${MANPATH%:}"
 528 | 		    MANPATH="${MANPATH#:}"
 529 | 		fi
 530 | 		# finally, clean up tmp variable
 531 | 		command unset MY_ALTS_TMP
 532 | 	RMTMP
 533 | }
 534 | 
 535 | function help_import() {
 536 | 	cat <<-'USAGE'
 537 | 		usage: my-alternatives import <name>
 538 | 
 539 | 		  imports an alternative group into the currently-configured alternatives.
 540 | 
 541 | 		  when the default alternatives (ie. MY_ALTS_HOME) are active:
 542 | 		    * tries to import from the system-level alternatives
 543 | 
 544 | 		  when temporary alternatives (i.e MY_ALTS_TMP) are active:
 545 | 		    * first tries to import from the default alternatives
 546 | 		    * finally tries to import from the system-level alternatives
 547 | 
 548 | 		more info:
 549 | 
 550 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 551 | 
 552 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 553 | 
 554 | 	USAGE
 555 | 	exit 2
 556 | }
 557 | 
 558 | function do_import() {
 559 | 	# Ensure alt_home configured
 560 | 	#
 561 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 562 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 563 | 		exit 2
 564 | 	fi
 565 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
 566 | 	local name
 567 | 	while (($#)); do
 568 | 		case "${1}" in
 569 | 			*)
 570 | 				# If name already defined
 571 | 				#
 572 | 				if [ -n "${name:-}" ]; then
 573 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help import' for usage\n" "${1}" >&2
 574 | 					exit 2
 575 | 				fi
 576 | 				name="${1}"
 577 | 				shift
 578 | 				;;
 579 | 		esac
 580 | 	done
 581 | 	# No name argument
 582 | 	#
 583 | 	if [[ -z "${name:-}" ]]; then
 584 | 		printf "my-alternatives: error: no name provided. see 'my-alternatives help import' for usage\n" >&2
 585 | 		exit 1
 586 | 	fi
 587 | 	local from # for status message
 588 | 	local data_file
 589 | 	# Create temp file
 590 | 	#
 591 | 	if ! data_file="$(command mktemp -q -t "my-alts-${name}-query.XXXXXXXX")"; then
 592 | 		printf "my-alternatives: error: unable to create temp file\n" >&2
 593 | 		exit 2
 594 | 	fi
 595 | 	# sanity check
 596 | 	if [ ! -f "${data_file}" ]; then
 597 | 		printf "my-alternatives: error: unable to create temp file\n" >&2
 598 | 		exit 2
 599 | 	fi
 600 | 	# If tmp is active try import from home
 601 | 	#
 602 | 	if [ "${alt_root}" = "${MY_ALTS_TMP:-}" ]; then
 603 | 		# does NOT exit on error - checks data_file for success
 604 | 		command update-alternatives \
 605 | 			--altdir "${MY_ALTS_HOME}/alts" --admindir "${MY_ALTS_HOME}/admin" \
 606 | 			--query "${name}" \
 607 | 			>"${data_file}" 2>/dev/null || true
 608 | 
 609 | 		if [ -s "${data_file}" ]; then
 610 | 			from="MY_ALTS_HOME: ${MY_ALTS_HOME}" # for status message
 611 | 		fi
 612 | 	fi
 613 | 	if [ -z "${from:-}" ]; then
 614 | 		# final fallback = update-alternatives default
 615 | 		# exits on error
 616 | 		command update-alternatives --query "${name}" >"${data_file}"
 617 | 
 618 | 		if [ -s "${data_file}" ]; then
 619 | 			from="system-level alternative" # for status message
 620 | 		fi
 621 | 	fi
 622 | 	# final sanity check
 623 | 	#
 624 | 	if [ -z "${from:-}" ]; then
 625 | 		printf "my-alternatives: error: unable to locate alternative group with name %s\n" "${name}" >&2
 626 | 		rm "${data_file}"
 627 | 		exit 2
 628 | 	fi
 629 | 
 630 | 	alt_parse_query "${data_file}" || return $?
 631 | 	rm "${data_file}"
 632 | 
 633 | 	if [ -z "${ALT_GROUP_LINK}" ]; then
 634 | 		printf "my-alternatives: error: unable to determine provided location\n" >&2
 635 | 		exit 2
 636 | 	fi
 637 | 
 638 | 	printf "importing alternative group %s%s from %s\n" "${ALT_GROUP_NAME}" "${ALT_GROUP_STATUS:+" in ${ALT_GROUP_STATUS} mode"}" "${from}"
 639 | 
 640 | 	local alt_group_link_rel
 641 | 	alt_group_link_rel="$(get_my_alt_rel_path "${ALT_GROUP_LINK}")"
 642 | 	if [ "${alt_group_link_rel}" == "${ALT_GROUP_LINK}" ]; then
 643 | 		printf "my-alternatives: error: unable to determine relative path for primary link: %s\n" "${ALT_GROUP_LINK}" >&2
 644 | 		exit 2
 645 | 	fi
 646 | 	ALT_GROUP_LINK="${alt_root}${alt_group_link_rel}"
 647 | 	local a=0
 648 | 	while [[ $a -lt ${#ALT_GROUP_VALUES[@]} ]]; do
 649 | 		local alt_value="${ALT_GROUP_VALUES[$a]}"
 650 | 		local alt_priority="${ALT_GROUP_PRIORITIES[$a]}"
 651 | 		local child_args=()
 652 | 		local s=0
 653 | 		while [[ $s -lt ${#ALT_GROUP_SLAVE_NAMES[@]} ]]; do
 654 | 			local child_name="${ALT_GROUP_SLAVE_NAMES[$s]}"
 655 | 			local child_link="${ALT_GROUP_SLAVE_LINKS[$s]}"
 656 | 			local child_link_rel
 657 | 			child_link_rel="$(get_my_alt_rel_path "${child_link}")"
 658 | 			if [ "${child_link_rel}" == "${child_link}" ]; then
 659 | 				printf " !!! warning: Unable to determine type (bin/man/etc) for %s\n" "${child_name} @ ${child_link} - skipping" >&2
 660 | 			else
 661 | 				child_link="${alt_root}${child_link_rel}"
 662 | 				local child_value_ref="ALT_GROUP_VALUE_${a}_SLAVE_${s}_VALUE"
 663 | 				local child_value="${!child_value_ref}"
 664 | 				# Did we find a child value?
 665 | 				#
 666 | 				if [[ -n "${child_value}" ]]; then
 667 | 					child_args+=("--slave" "${child_link}" "${child_name}" "${child_value}")
 668 | 				else
 669 | 					printf " !!! warning: Unable to determine type (bin/man/etc) for %s\n" "${child_name} @ ${child_link} - skipping" >&2
 670 | 				fi
 671 | 			fi
 672 | 			((s += 1))
 673 | 		done
 674 | 
 675 | 		printf " ... importing alternative %s with priority %s\n" "${alt_value}" "${alt_priority}"
 676 | 		command update-alternatives \
 677 | 			--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 678 | 			--install "${ALT_GROUP_LINK}" "${ALT_GROUP_NAME}" "${alt_value}" "${alt_priority}" \
 679 | 			"${child_args[@]}" \
 680 | 			>/dev/null || return $?
 681 | 
 682 | 		((a += 1))
 683 | 	done
 684 | 	# Set current value if manual mode
 685 | 	#
 686 | 	if [ "${ALT_GROUP_STATUS}" = "manual" ] && [ ! "${ALT_GROUP_CURRENT_VALUE:-none}" = "none" ]; then
 687 | 		printf " ... marking %s as active alternative\n" "${ALT_GROUP_CURRENT_VALUE}"
 688 | 		command update-alternatives \
 689 | 			--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 690 | 			--set "${ALT_GROUP_NAME}" "${ALT_GROUP_CURRENT_VALUE}" \
 691 | 			>/dev/null || return $?
 692 | 	fi
 693 | 	# finished
 694 | 	printf "\n"
 695 | }
 696 | 
 697 | function help_add() {
 698 | 	cat <<-'USAGE'
 699 | 		usage: my-alternatives add <group-name> <group-path> <alt-path> <alt-priority> [--child <group-name> <group-path> <alt-path>]...
 700 | 
 701 | 		  adds an alternative to a group within the currently-configured alternatives.
 702 | 		  The group is created if it does not already exist.
 703 | 
 704 | 		  NOTE: This is generally a pass-through to 'update-alternatives --install', BUT the argument syntax is slightly diffrent:
 705 | 
 706 | 		    * the order of <group-name> and <group-path> arguments are inverted
 707 | 		    * uses --child (vs --slave) for secondary files
 708 | 		    * <group-path> arguments should be relative
 709 | 		        ex: bin/pager
 710 | 		        ex: man/man1/pager.1.gz
 711 | 
 712 | 		options:
 713 | 
 714 | 		  <group-name>
 715 | 		     the name of the alternative group.
 716 | 		     used when referring to the group in other commands.
 717 | 		     the name must be unique within the currently-configured alternatives.
 718 | 		     ex: pager
 719 | 		     ex: pager.1.gz
 720 | 
 721 | 		  <group-path>
 722 | 		     path provided by the group.
 723 | 		     path should be relative.
 724 | 		     ex: bin/pager
 725 | 		     ex: man/man1/pager.1.gz
 726 | 
 727 | 		  <alt-path>
 728 | 		     the path of the alternative being introduced.
 729 | 		     ex: /usr/bin/less
 730 | 		     ex: /usr/share/man/man1/less.1.gz
 731 | 
 732 | 		  <alt-priority>
 733 | 		     priority of this alternative.
 734 | 		     alternatives with larger values have higher priority in automatic mode.
 735 | 
 736 | 		  --child <group-name> <group-path> <alt-path>
 737 | 		     adds a secondary entry.
 738 | 		     optional, but if given, all arguments are required.
 739 | 
 740 | 		more info:
 741 | 
 742 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 743 | 
 744 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--install' command.
 745 | 
 746 | 	USAGE
 747 | 	exit 2
 748 | }
 749 | 
 750 | function do_add() {
 751 | 	# Ensure alt_home configured
 752 | 	#
 753 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 754 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 755 | 		exit 2
 756 | 	fi
 757 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
 758 | 	# Build update-alternatives --install args
 759 | 	#
 760 | 	local args=("--install")
 761 | 	local providing_name providing_path
 762 | 	# primary group-name
 763 | 	#
 764 | 	if [ -z "${1:-}" ]; then
 765 | 		printf "my-alternatives: error: primary group-name not provided. see 'my-alternatives help add' for usage\n" >&2
 766 | 		exit 1
 767 | 	fi
 768 | 	providing_name="${1}"
 769 | 	shift
 770 | 	# primary group-path
 771 | 	#
 772 | 	if [ -z "${1:-}" ]; then
 773 | 		printf "my-alternatives: error: primary group-path not provided. see 'my-alternatives help add' for usage\n" >&2
 774 | 		exit 1
 775 | 	fi
 776 | 	if [[ "${1}" =~ ^/(bin|man)/ ]]; then
 777 | 		providing_path="${alt_root}${1}"
 778 | 	elif [[ "${1}" =~ ^(bin|man)/ ]]; then
 779 | 		providing_path="${alt_root}/${1}"
 780 | 	else
 781 | 		local group_path
 782 | 		group_path="$(get_my_alt_rel_path "${1}")"
 783 | 		if [ "${group_path}" == "${1}" ]; then
 784 | 			printf "my-alternatives: error: unable to determine relative path for group-path: %s\n" "${group_path}" >&2
 785 | 			exit 2
 786 | 		fi
 787 | 		providing_path="${alt_root}${group_path}"
 788 | 	fi
 789 | 	shift
 790 | 
 791 | 	# add to args (inverted)
 792 | 	args+=("${providing_path}" "${providing_name}")
 793 | 
 794 | 	# primary alt-path
 795 | 	#
 796 | 	if [ -z "${1:-}" ]; then
 797 | 		printf "my-alternatives: error: primary alt-path not provided. see 'my-alternatives help add' for usage\n" >&2
 798 | 		exit 1
 799 | 	fi
 800 | 	args+=("${1}")
 801 | 	shift
 802 | 	# alt-priority
 803 | 	#
 804 | 	if [ -z "${1:-}" ]; then
 805 | 		printf "my-alternatives: error: alt-priority not provided. see 'my-alternatives help install' for usage\n" >&2
 806 | 		exit 1
 807 | 	fi
 808 | 	args+=("${1}")
 809 | 	shift
 810 | 	# children
 811 | 	#
 812 | 	while (($#)); do
 813 | 		case "${1}" in
 814 | 			--child)
 815 | 				args+=("--slave")
 816 | 				shift
 817 | 				# secondary group-name
 818 | 				#
 819 | 				if [ -z "${1:-}" ]; then
 820 | 					printf "my-alternatives: error: secondary group-name not provided. see 'my-alternatives help add' for usage\n" >&2
 821 | 					exit 1
 822 | 				fi
 823 | 				providing_name="${1}"
 824 | 				shift
 825 | 				# secondary group-path
 826 | 				#
 827 | 				if [ -z "${1:-}" ]; then
 828 | 					printf "my-alternatives: error: secondary group-path not provided. see 'my-alternatives help add' for usage\n" >&2
 829 | 					exit 1
 830 | 				fi
 831 | 				if [[ "${1}" =~ ^/(bin|man)/ ]]; then
 832 | 					providing_path="${alt_root}${1}"
 833 | 				elif [[ "${1}" =~ ^(bin|man)/ ]]; then
 834 | 					providing_path="${alt_root}/${1}"
 835 | 				else
 836 | 					local group_path
 837 | 					group_path="$(get_my_alt_rel_path "${1}")"
 838 | 					if [ "${group_path}" == "${1}" ]; then
 839 | 						printf "my-alternatives: error: unable to determine relative path for group-path: %s\n" "${group_path}" >&2
 840 | 						exit 2
 841 | 					fi
 842 | 					providing_path="${alt_root}${group_path}"
 843 | 				fi
 844 | 				shift
 845 | 
 846 | 				# add to args (inverted)
 847 | 				args+=("${providing_path}" "${providing_name}")
 848 | 
 849 | 				# secondary alt-path
 850 | 				#
 851 | 				if [ -z "${1:-}" ]; then
 852 | 					printf "my-alternatives: error: secondary alt-path not provided. see 'my-alternatives help add' for usage\n" >&2
 853 | 					exit 1
 854 | 				fi
 855 | 				args+=("${1}")
 856 | 				shift
 857 | 				;;
 858 | 			*)
 859 | 				printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help add' for usage\n" "${1}" >&2
 860 | 				exit 2
 861 | 				;;
 862 | 		esac
 863 | 	done
 864 | 
 865 | 	command update-alternatives \
 866 | 		--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 867 | 		"${args[@]}" \
 868 | 		>/dev/null || return $?
 869 | }
 870 | 
 871 | function help_select() {
 872 | 	cat <<-'USAGE'
 873 | 		usage: my-alternatives <select | config> <name>
 874 | 
 875 | 		  shows alternatives for the group <name> and asks the user to select which one to use.
 876 | 
 877 | 		  calls 'import <name>' if the group is not present in the currently-configured alternatives.
 878 | 
 879 | 		more info:
 880 | 
 881 | 		  see 'my-alternatives --help' to learn more about the 'import' command.
 882 | 
 883 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--config' command.
 884 | 
 885 | 	USAGE
 886 | 	exit 2
 887 | }
 888 | 
 889 | function do_select() {
 890 | 	# Ensure alt_home configured
 891 | 	#
 892 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 893 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 894 | 		exit 2
 895 | 	fi
 896 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
 897 | 	# No name argument
 898 | 	#
 899 | 	if [[ -z "${1:-}" ]]; then
 900 | 		printf "my-alternatives: error: no name provided. see 'my-alternatives help select' for usage\n" >&2
 901 | 		exit 1
 902 | 	fi
 903 | 	local name="${1}"
 904 | 	shift
 905 | 	# No further arguments expected
 906 | 	#
 907 | 	if [[ $# -gt 0 ]]; then
 908 | 		printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help select' for usage\n" "${1}" >&2
 909 | 		exit 2
 910 | 	fi
 911 | 	# need to import?
 912 | 	#
 913 | 	if ! alt_group_exists "${name}"; then
 914 | 		do_import "${name}" || return $?
 915 | 	fi
 916 | 	command update-alternatives \
 917 | 		--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 918 | 		"--config" "${name}"
 919 | }
 920 | 
 921 | ##
 922 | # help_alias
 923 | # Generates help text for the various command aliases
 924 | #
 925 | # $1 = command
 926 | # $2 = alias
 927 | #
 928 | function help_alias() {
 929 | 	# Need to escape $ and \
 930 | 	cat <<-USAGE
 931 | 		${2} is an alias for the '${1}' command.
 932 | 
 933 | 		see 'my-alternatives help ${1}' for usage.
 934 | 
 935 | 	USAGE
 936 | 	exit 2
 937 | }
 938 | 
 939 | ##
 940 | # help_passthrough
 941 | # Generates help text for the various pass-through commands
 942 | #
 943 | # $1 = update-alternatives command
 944 | # $2 = my-alternatives command (optional)
 945 | #
 946 | function help_passthrough() {
 947 | 	# Need to escape $ and \
 948 | 	cat <<-USAGE
 949 | 		usage: my-alternatives ${2:-${1}} [option ...]
 950 | 
 951 | 		  invokes update-alternatives --${1} pointing to the currently-configured alternatives.
 952 | 
 953 | 		  all options are passed through, unmodified.
 954 | 
 955 | 		this is equivilent to:
 956 | 
 957 | 		  # <ALT_ROOT>="\${MY_ALTS_TMP:-\${MY_ALTS_HOME}}"
 958 | 		  update-alternatives --altdir "<ALT_ROOT>/alts" --admindir "<ALT_ROOT>/admin" --${1} [option ...]
 959 | 
 960 | 		more info:
 961 | 
 962 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--${1}' command.
 963 | 
 964 | 	USAGE
 965 | 	exit 2
 966 | }
 967 | 
 968 | function help_update_alternatives_help() {
 969 | 	cat <<-'USAGE'
 970 | 		usage: my-alternatives ua-help
 971 | 
 972 | 		convenience command for invoking:
 973 | 
 974 | 		  update-alternatives --help
 975 | 
 976 | 	USAGE
 977 | 	exit 2
 978 | }
 979 | 
 980 | function help_update_alternatives_version() {
 981 | 	cat <<-'USAGE'
 982 | 		usage: my-alternatives ua-version
 983 | 
 984 | 		convenience command for invoking:
 985 | 
 986 | 		  update-alternatives --version
 987 | 
 988 | 	USAGE
 989 | 	exit 2
 990 | }
 991 | 
 992 | function help_update_alternatives() {
 993 | 	cat <<-'USAGE'
 994 | 		usage: my-alternatives ua [option ...]
 995 | 
 996 | 		  invokes update-alternatives pointing to the currently-configured alternatives.
 997 | 
 998 | 		  all options are passed through, unmodified.
 999 | 
1000 | 		this is equivilent to:
1001 | 
1002 | 		  # <ALT_ROOT>="\${MY_ALTS_TMP:-\${MY_ALTS_HOME}}"
1003 | 		  update-alternatives --altdir "<ALT_ROOT>/alts" --admindir "<ALT_ROOT>/admin" [option ...]
1004 | 
1005 | 		more info:
1006 | 
1007 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
1008 | 
1009 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
1010 | 
1011 | 	USAGE
1012 | 	exit 2
1013 | }
1014 | 
1015 | function do_update_alternatives() {
1016 | 	# Ensure alt_home configured
1017 | 	#
1018 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
1019 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
1020 | 		exit 2
1021 | 	fi
1022 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
1023 | 	# Invoke update-alternatives
1024 | 	#
1025 | 	command update-alternatives \
1026 | 		--altdir "${alt_root}/alts" \
1027 | 		--admindir "${alt_root}/admin" \
1028 | 		"$@"
1029 | }
1030 | 
1031 | ##
1032 | # alt_group_exists
1033 | # Checks if a named alt group exists in the configured alt root
1034 | # $1 = name
1035 | #
1036 | # returns 0 if exist 1 otherwise
1037 | #
1038 | function alt_group_exists() {
1039 | 	local list
1040 | 	# TODO This can likely be simplified
1041 | 	if list="$(do_update_alternatives --list "${1}" 2>/dev/null || true)"; then
1042 | 		if [ -n "${list}" ]; then
1043 | 			return 0
1044 | 		fi
1045 | 	fi
1046 | 	return 1
1047 | }
1048 | 
1049 | ##
1050 | # is_dir_in_path
1051 | # Checks if the provided entry exists in the provided colon-separated list
1052 | #
1053 | # $1 = path ( or any colon-sepearated list )
1054 | # $2 = dir ( entry to look for )
1055 | #
1056 | # Returns 0 if found 1 otherwise
1057 | #
1058 | # exmaple:
1059 | #
1060 | #    is_dir_in_path "${PATH}" /usr/local/bin && echo YES || echo NO
1061 | #
1062 | function is_dir_in_path() {
1063 | 	# 0 = success
1064 | 	# Most likely to be in middle, least likely to match full path
1065 | 	#
1066 | 	[[ "$1" == *":$2:"* || "$1" == "$2:"* || "$1" == *":$2" || "$1" == "$2" ]] && return 0 || return 1
1067 | }
1068 | 
1069 | ##
1070 | # $1 = file (assumed to represent a file ie last element removed for path checks)
1071 | #
1072 | function get_my_alt_rel_path() {
1073 | 	local file path
1074 | 	if [ "${1}" == "" ]; then
1075 | 		printf ""
1076 | 		return
1077 | 	else
1078 | 		file="$(basename "$1")"
1079 | 		path="$(dirname "$1")"
1080 | 		if [ "${file}" == "" ] || [ "${path}" == "." ] || [ "${path}" == "/" ]; then
1081 | 			printf "%s" "$1"
1082 | 			return
1083 | 		fi
1084 | 	fi
1085 | 	# Check $PATH
1086 | 	#
1087 | 	if is_dir_in_path "${PATH}" "${path}"; then
1088 | 		printf "/bin/%s" "${file}"
1089 | 		return
1090 | 	fi
1091 | 	# Check manpath
1092 | 	#
1093 | 	if command -v manpath &>/dev/null; then
1094 | 		local _manpath
1095 | 		_manpath="$(command manpath 2>/dev/null)"
1096 | 		while [ "${path}" != "." ] && [ "${path}" != "/" ]; do
1097 | 			if is_dir_in_path "${_manpath}" "${path}"; then
1098 | 				printf "/man/%s" "${file}"
1099 | 				return
1100 | 			fi
1101 | 			file="$(command basename "${path}")/${file}"
1102 | 			path="$(command dirname "${path}")"
1103 | 		done
1104 | 	fi
1105 | 	# Unknown
1106 | 	#
1107 | 	printf "%s" "$1"
1108 | }
1109 | 
1110 | # ##############################################################################
1111 | # BEGIN alternatives_parse_query.bash v1.0.0
1112 | #       https://gist.github.com/TekWizely/f14c787fd7ecf7719d2963265a6e7d08
1113 | # ##############################################################################
1114 | 
1115 | ##
1116 | # alt_parse_query - Parses the output of 'update-alternatives --query'
1117 | #
1118 | # $1 = file to read from (can be process sub)
1119 | # $2 = debug|trace
1120 | #
1121 | # example:
1122 | #
1123 | #    alt_parse_query <( update-alternatives --query pager )
1124 | #
1125 | function alt_parse_query() {
1126 | 	# Reset global vars
1127 | 	#
1128 | 	ALT_GROUP_LINK=
1129 | 	ALT_GROUP_NAME=
1130 | 	ALT_GROUP_SLAVE_NAMES=()
1131 | 	ALT_GROUP_SLAVE_LINKS=()
1132 | 	ALT_GROUP_STATUS= # auto | manual
1133 | 	ALT_GROUP_CURRENT_VALUE=
1134 | 	ALT_GROUP_CURRENT_INDEX=
1135 | 	ALT_GROUP_BEST_VALUE=
1136 | 	ALT_GROUP_BEST_INDEX=
1137 | 	ALT_GROUP_VALUES=()
1138 | 	ALT_GROUP_PRIORITIES=()
1139 | 	# TODO Consider moving to serialized arrays for slave values
1140 | 	#ALT_GROUP_VALUE_${v}_SLAVE_${s}_VALUE
1141 | 
1142 | 	_ALT_PARSE_QUERY_STATE="NAME"
1143 | 	local IFS line lineno=0 # 1 on first use
1144 | 	while IFS="" read -r line || [ -n "${line}" ]; do
1145 | 		((lineno += 1))
1146 | 		# Keeps looping on return code 3, otherwise returns on !0
1147 | 		#
1148 | 		local return_code
1149 | 		while :; do
1150 | 			if [ "${2:-}" == "trace" ]; then
1151 | 				printf "# line NO  : %s\n" "${lineno}"
1152 | 				printf "# line TEXT: '%s'\n" "${line}"
1153 | 				printf "# state    : %s\n" "${_ALT_PARSE_ADMIN_STATE}"
1154 | 				printf "#  ---------\n"
1155 | 			fi
1156 | 			_alt_parse_query_state_"${_ALT_PARSE_QUERY_STATE}" "${line}"
1157 | 			return_code=$?
1158 | 			[[ $return_code -eq 3 ]] || break
1159 | 		done
1160 | 		[[ $return_code -eq 0 ]] || return $return_code
1161 | 	done <"${1}"
1162 | 	# Final state should be one of "eof candidate" states
1163 | 	#
1164 | 	if [ ! "${_ALT_PARSE_QUERY_STATE}" = "MAYBE_ALT_START" ] && [ ! "${_ALT_PARSE_QUERY_STATE}" = "MAYBE_ALT_SLAVES_HEADER" ] && [ ! "${_ALT_PARSE_QUERY_STATE}" = "MAYBE_ALT_SLAVE_ENTRY" ]; then
1165 | 		printf "unexpected parse state: %s\n" "${_ALT_PARSE_QUERY_STATE}" >&2
1166 | 		return 2
1167 | 	fi
1168 | 	if [ "${2:-}" == "trace" ] || [ "${2:-}" == "debug" ]; then
1169 | 		printf "ALT_GROUP_NAME         : %s\n" "${ALT_GROUP_NAME}"
1170 | 		printf "ALT_GROUP_LINK         : %s\n" "${ALT_GROUP_LINK}"
1171 | 		printf "ALT_GROUP_SLAVE_NAMES  : %s\n" "${ALT_GROUP_SLAVE_NAMES[*]}"
1172 | 		printf "ALT_GROUP_SLAVE_LINKS  : %s\n" "${ALT_GROUP_SLAVE_LINKS[*]}"
1173 | 		printf "ALT_GROUP_STATUS       : %s\n" "${ALT_GROUP_STATUS}"
1174 | 		printf "ALT_GROUP_CURRENT_VALUE: %s\n" "${ALT_GROUP_CURRENT_VALUE}"
1175 | 		printf "ALT_GROUP_CURRENT_INDEX: %s\n" "${ALT_GROUP_CURRENT_INDEX}"
1176 | 		printf "ALT_GROUP_BEST_VALUE   : %s\n" "${ALT_GROUP_BEST_VALUE}"
1177 | 		printf "ALT_GROUP_BEST_INDEX   : %s\n" "${ALT_GROUP_BEST_INDEX}"
1178 | 		printf "ALT_GROUP_VALUES       : %s\n" "${ALT_GROUP_VALUES[*]}"
1179 | 		printf "ALT_GROUP_PRIORITIES   : %s\n" "${ALT_GROUP_PRIORITIES[*]}"
1180 | 		local v=0
1181 | 		while [[ $v -lt ${#ALT_GROUP_VALUES[@]} ]]; do
1182 | 			local s=0
1183 | 			while [[ $s -lt ${#ALT_GROUP_SLAVE_NAMES[@]} ]]; do
1184 | 				local alt_slave_value_ref="ALT_GROUP_VALUE_${v}_SLAVE_${s}_VALUE"
1185 | 				printf "${alt_slave_value_ref} : %s\n" "${!alt_slave_value_ref}"
1186 | 				((s += 1))
1187 | 			done
1188 | 			((v += 1))
1189 | 		done
1190 | 	fi
1191 | }
1192 | 
1193 | function _alt_parse_query_state_NAME() {
1194 | 	local regex="^Name: (.+)$"
1195 | 	if [[ "${1}" =~ $regex ]]; then
1196 | 		ALT_GROUP_NAME="${BASH_REMATCH[1]}"
1197 | 		_ALT_PARSE_QUERY_STATE="LINK"
1198 | 		return 0
1199 | 	else
1200 | 		printf "unable to parse Name field: %s\n" "${1}" >&2
1201 | 		return 2
1202 | 	fi
1203 | }
1204 | 
1205 | function _alt_parse_query_state_LINK() {
1206 | 	local regex="^Link: (.+)$"
1207 | 	if [[ "${1}" =~ $regex ]]; then
1208 | 		ALT_GROUP_LINK="${BASH_REMATCH[1]}"
1209 | 		_ALT_PARSE_QUERY_STATE="MAYBE_SLAVES_HEADER"
1210 | 		return 0
1211 | 	else
1212 | 		printf "unable to parse Primary Link field: %s\n" "${1}" >&2
1213 | 		return 2
1214 | 	fi
1215 | }
1216 | 
1217 | function _alt_parse_query_state_MAYBE_SLAVES_HEADER() {
1218 | 	if [[ "${1}" =~ ^Slaves:$ ]]; then
1219 | 		_ALT_PARSE_QUERY_STATE="SLAVE_ENTRY"
1220 | 		return 0
1221 | 	else
1222 | 		_ALT_PARSE_QUERY_STATE="STATUS"
1223 | 		return 3 # re-check line
1224 | 	fi
1225 | }
1226 | 
1227 | function _alt_parse_query_state_SLAVE_ENTRY() {
1228 | 	local regex="^ ([^ ]+) (.+)$"
1229 | 	if [[ "${1}" =~ $regex ]]; then
1230 | 		ALT_GROUP_SLAVE_NAMES+=("${BASH_REMATCH[1]}")
1231 | 		ALT_GROUP_SLAVE_LINKS+=("${BASH_REMATCH[2]}")
1232 | 		# Leave status unchanged
1233 | 		return 0
1234 | 	else
1235 | 		_ALT_PARSE_QUERY_STATE="STATUS"
1236 | 		return 3 # re-check line
1237 | 	fi
1238 | }
1239 | 
1240 | function _alt_parse_query_state_STATUS() {
1241 | 	local regex="^Status: (.+)$"
1242 | 	if [[ "${1}" =~ $regex ]]; then
1243 | 		ALT_GROUP_STATUS="${BASH_REMATCH[1]}"
1244 | 		_ALT_PARSE_QUERY_STATE="BEST"
1245 | 		return 0
1246 | 	else
1247 | 		printf "unable to parse Status field: %s\n" "${1}" >&2
1248 | 		return 2
1249 | 	fi
1250 | }
1251 | 
1252 | function _alt_parse_query_state_BEST() {
1253 | 	local regex="^Best: (.+)$"
1254 | 	if [[ "${1}" =~ $regex ]]; then
1255 | 		ALT_GROUP_BEST_VALUE="${BASH_REMATCH[1]}"
1256 | 		_ALT_PARSE_QUERY_STATE="VALUE"
1257 | 		return 0
1258 | 	else
1259 | 		printf "unable to parse Best Value field: %s\n" "${1}" >&2
1260 | 		return 2
1261 | 	fi
1262 | }
1263 | 
1264 | function _alt_parse_query_state_VALUE() {
1265 | 	local regex="^Value: (.+)$"
1266 | 	if [[ "${1}" =~ $regex ]]; then
1267 | 		ALT_GROUP_CURRENT_VALUE="${BASH_REMATCH[1]}"
1268 | 		_ALT_PARSE_QUERY_STATE="MAYBE_ALT_START"
1269 | 		return 0
1270 | 	else
1271 | 		printf "unable to parse Primary Value field: %s\n" "${1}" >&2
1272 | 		return 2
1273 | 	fi
1274 | }
1275 | 
1276 | # eof candidate
1277 | function _alt_parse_query_state_MAYBE_ALT_START() {
1278 | 	if [[ "${1}" != "" ]]; then
1279 | 		printf "expecting blank line to start an Alternative Entry: %s\n" "${1}" >&2
1280 | 		return 2
1281 | 	fi
1282 | 	_ALT_PARSE_QUERY_STATE="ALT_VALUE"
1283 | 	return 0
1284 | }
1285 | 
1286 | function _alt_parse_query_state_ALT_VALUE() {
1287 | 	local regex="^Alternative: (.+)$"
1288 | 	if [[ "${1}" =~ $regex ]]; then
1289 | 		local alt_value="${BASH_REMATCH[1]}"
1290 | 		local alt_index=${#ALT_GROUP_VALUES[@]} # assign before += for 0-based value
1291 | 		ALT_GROUP_VALUES+=("${alt_value}")
1292 | 		# best alt index
1293 | 		#
1294 | 		if [ "${alt_value}" == "${ALT_GROUP_BEST_VALUE}" ]; then
1295 | 			ALT_GROUP_BEST_INDEX=$alt_index
1296 | 		fi
1297 | 		# current alt index
1298 | 		#
1299 | 		if [ "${alt_value}" == "${ALT_GROUP_CURRENT_VALUE}" ]; then
1300 | 			ALT_GROUP_CURRENT_INDEX=$alt_index
1301 | 		fi
1302 | 		_ALT_PARSE_QUERY_STATE="ALT_PRIORITY"
1303 | 		return 0
1304 | 	else
1305 | 		printf "unable to parse Alternative Value field: %s\n" "${1}" >&2
1306 | 		return 2
1307 | 	fi
1308 | }
1309 | 
1310 | function _alt_parse_query_state_ALT_PRIORITY() {
1311 | 	local regex="^Priority: ([0-9]+)$"
1312 | 	if [[ "${1}" =~ $regex ]]; then
1313 | 		ALT_GROUP_PRIORITIES+=("${BASH_REMATCH[1]}")
1314 | 		_ALT_PARSE_QUERY_STATE="MAYBE_ALT_SLAVES_HEADER"
1315 | 		return 0
1316 | 	else
1317 | 		printf "unable to parse Alternative Priority field: %s\n" "${1}" >&2
1318 | 		return 2
1319 | 	fi
1320 | }
1321 | 
1322 | # eof candidate
1323 | function _alt_parse_query_state_MAYBE_ALT_SLAVES_HEADER() {
1324 | 	if [[ "${1}" =~ ^Slaves:$ ]]; then
1325 | 		_ALT_PARSE_QUERY_STATE="MAYBE_ALT_SLAVE_ENTRY"
1326 | 		return 0
1327 | 	else
1328 | 		_ALT_PARSE_QUERY_STATE="MAYBE_ALT_START"
1329 | 		return 3 # re-check line
1330 | 	fi
1331 | }
1332 | 
1333 | # eof candidate
1334 | function _alt_parse_query_state_MAYBE_ALT_SLAVE_ENTRY() {
1335 | 	local regex="^ ([^ ]+) (.+)$"
1336 | 	if [[ "${1}" =~ $regex ]]; then
1337 | 		local slave_name="${BASH_REMATCH[1]}"
1338 | 		local slave_value="${BASH_REMATCH[2]}"
1339 | 		local slave_name_index=
1340 | 		local i=0
1341 | 		while [[ $i -lt ${#ALT_GROUP_SLAVE_NAMES[@]} ]]; do
1342 | 			if [ "${ALT_GROUP_SLAVE_NAMES[$i]}" == "${slave_name}" ]; then
1343 | 				slave_name_index=$i
1344 | 				break
1345 | 			fi
1346 | 			i=$((i + 1))
1347 | 		done
1348 | 		# find it?
1349 | 		if [ -n "${slave_name_index}" ]; then
1350 | 			local alt_index=$((${#ALT_GROUP_VALUES[@]} - 1))
1351 | 			local slave_value_ref="ALT_GROUP_VALUE_${alt_index}_SLAVE_${slave_name_index}_VALUE"
1352 | 			declare -g "${slave_value_ref}"="${slave_value}"
1353 | 		#else
1354 | 		#	printf "unable to match Alternative Slave Name: %s - skipping\n" "${1}" >&2
1355 | 		fi
1356 | 		# Leave status unchanged
1357 | 		return 0
1358 | 	else
1359 | 		_ALT_PARSE_QUERY_STATE="MAYBE_ALT_START"
1360 | 		return 3 # re-check line
1361 | 	fi
1362 | }
1363 | 
1364 | # ##############################################################################
1365 | # END alternatives_parse_query.bash
1366 | # ##############################################################################
1367 | 
1368 | # Only process main logic if not being sourced (ie tested)
1369 | #
1370 | (return 0 2>/dev/null) || main "$@"
1371 | 


--------------------------------------------------------------------------------
/my-alternatives-redhat:
--------------------------------------------------------------------------------
   1 | #!/usr/bin/env bash
   2 | #######################################################################
   3 | # SPDX-License-Identifier: MIT
   4 | # Copyright (c) 2021 TekWizely & co-authors
   5 | #
   6 | # Use of this source code is governed by the MIT license.
   7 | # See the accompanying LICENSE file, if present, or visit:
   8 | #   https://opensource.org/licenses/MIT
   9 | #######################################################################
  10 | VERSION="v0.7.0-redhat"
  11 | 
  12 | set -Eeuo pipefail
  13 | umask 077 # We use tmp files. Try to protect the user
  14 | 
  15 | function usage() {
  16 | 	# Need to escape $ and \
  17 | 	cat <<-USAGE
  18 | 		my-alternatives (${VERSION})
  19 | 
  20 | 		  a wrapper for update-alternatives to enable user-level configuration.
  21 | 		  also supports temporary (per-shell) changes.
  22 | 
  23 | 		usage:
  24 | 
  25 | 		  eval "\$( my-alternatives <init | shellenv> [--shell <shell>] [--admin-dir <system_admin_dir>] [--alt-dir <system_alt_dir>] [alt_home])"
  26 | 		    prepare the current shell session for user-level alternatives
  27 | 		    NOTE: place this in your .profile
  28 | 		  my-alternatives <init-tmp | tmp> [tmp_dir]
  29 | 		    configure the current shell session for temporary (short-lived) changes
  30 | 		  my-alternatives <rm-tmp | rmtmp>
  31 | 		    remove the temporary configuration from the current shell session
  32 | 		  my-alternatives <command> [option ...]
  33 | 		    invoke a command
  34 | 		  my-alternatives help <command>
  35 | 		    learn more about a specific command
  36 | 
  37 | 		custom commands:
  38 | 
  39 | 		  import <name>
  40 | 		    import the alternative group <name> into the current configuration
  41 | 		    when the default configuration is active, imports from system-level alternatives
  42 | 		    when a tmporary configuration is active, first tries the default configuration, then system-level alternatives
  43 | 		  add <name> ...
  44 | 		    add an alternative to the group <name> within the current configuration
  45 | 		    see 'help add' for usage details
  46 | 		  select | config <name>
  47 | 		    select the active alternative for group <name>
  48 | 		    will first invoke 'import <name>' if the group is not already available in the current configuration
  49 | 		  add-child <name> ...
  50 | 		    add a child to an existing alternative for group <name> within the current configuration
  51 | 		    see 'help add-child' for usage details
  52 | 		  version
  53 | 		    display my-alternatives version number
  54 | 
  55 | 		renamed pass-through commands:
  56 | 
  57 | 		  rm-alt | rmalt
  58 | 		    invoke 'update-alternatives --remove'
  59 | 		  rm-group | rmgrp
  60 | 		    invoke 'update-alternatives --remove-all'
  61 | 		  rm-child | rmchild
  62 | 		    invoke 'update-alternatives --remove-slave'
  63 | 
  64 | 		    these have been renamed to reduce ambiguity
  65 | 
  66 | 		same-name pass-through commands:
  67 | 
  68 | 		  display | list | set | auto
  69 | 
  70 | 		    invoke 'update-alternatives --<command>'
  71 | 
  72 | 		update-alternatives helper commands:
  73 | 
  74 | 		  ua [option ...]
  75 | 		    invoke 'update-alternatives [option ...]' pointing to the currently-configured alternatives
  76 | 		  ua-help
  77 | 		    invoke 'update-alternatives --help'
  78 | 		  ua-version
  79 | 		    invoke 'update-alternatives --version'
  80 | 
  81 | 	USAGE
  82 | 	exit 2
  83 | }
  84 | 
  85 | function version() {
  86 | 	printf "%s\n" "${VERSION}"
  87 | }
  88 | 
  89 | function main() {
  90 | 
  91 | 	case "${1:-}" in
  92 | 		-h | --help)
  93 | 			usage
  94 | 			;;
  95 | 		help)
  96 | 			shift
  97 | 			case "${1:-}" in
  98 | 				init)
  99 | 					help_init
 100 | 					;;
 101 | 				shellenv) # alias
 102 | 					help_alias "init" "$1"
 103 | 					;;
 104 | 				init-tmp)
 105 | 					help_init_tmp
 106 | 					;;
 107 | 				init-temp | tmp | temp) # aliases
 108 | 					help_alias "init-tmp" "$1"
 109 | 					;;
 110 | 				rm-tmp)
 111 | 					help_rm_tmp
 112 | 					;;
 113 | 				rm-temp | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp) # aliases
 114 | 					help_alias "rm-tmp" "$1"
 115 | 					;;
 116 | 				import)
 117 | 					help_import
 118 | 					;;
 119 | 				add)
 120 | 					help_add
 121 | 					;;
 122 | 				add-child)
 123 | 					help_add_child
 124 | 					;;
 125 | 				addchild)
 126 | 					help_alias "add-child" "$1"
 127 | 					;;
 128 | 				select)
 129 | 					help_select
 130 | 					;;
 131 | 				config) # alias
 132 | 					help_alias "select" "$1"
 133 | 					;;
 134 | 				version)
 135 | 					version
 136 | 					;;
 137 | 				#
 138 | 				# renamed update-alternatives pass-through
 139 | 				#
 140 | 				rm-alt | rmalt | remove-alt | removealt)
 141 | 					help_passthrough "remove" "$1"
 142 | 					;;
 143 | 				rm-group | rmgroup | rm-grp | rmgrp | remove-group | removegroup | remove-grp | removegrp)
 144 | 					help_passthrough "remove-all" "$1"
 145 | 					;;
 146 | 				rm-child | rmchild | remove-child | removechild)
 147 | 					help_passthrough "rm-slave" "$1"
 148 | 					;;
 149 | 				#
 150 | 				# update-alternatives pass-through
 151 | 				#
 152 | 				display | list | set | auto)
 153 | 					help_passthrough "$1"
 154 | 					;;
 155 | 				#
 156 | 				# update-alternatives helpers
 157 | 				#
 158 | 				ua)
 159 | 					help_update_alternatives
 160 | 					;;
 161 | 				ua-help)
 162 | 					help_update_alternatives_help
 163 | 					;;
 164 | 				ua-version)
 165 | 					help_update_alternatives_version
 166 | 					;;
 167 | 				*)
 168 | 					if [ -z "${1:-}" ]; then
 169 | 						printf "usage: help <command>\n" >&2
 170 | 					else
 171 | 						printf "error: unrecognized command: %s\n" "${1}" >&2
 172 | 					fi
 173 | 					printf "\nsee 'my-alternatives --help' for list of commands\n" >&2
 174 | 					exit 2
 175 | 					;;
 176 | 			esac
 177 | 			;;
 178 | 		init | shellenv)
 179 | 			shift
 180 | 			do_init "$@"
 181 | 			;;
 182 | 		init-tmp | init-temp | tmp | temp)
 183 | 			shift
 184 | 			do_init_tmp "$@"
 185 | 			;;
 186 | 		rm-tmp | rm-temp | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp)
 187 | 			shift
 188 | 			do_rm_tmp "$@"
 189 | 			;;
 190 | 		import)
 191 | 			shift
 192 | 			do_import "$@"
 193 | 			;;
 194 | 		add)
 195 | 			shift
 196 | 			do_add "$@"
 197 | 			;;
 198 | 		add-child | addchild)
 199 | 			shift
 200 | 			do_add_child "$@"
 201 | 			;;
 202 | 		select | config)
 203 | 			shift
 204 | 			do_select "$@"
 205 | 			;;
 206 | 		version)
 207 | 			version
 208 | 			;;
 209 | 		#
 210 | 		# renamed update-alternatives pass-through
 211 | 		#
 212 | 		rm-alt | rmalt | remove-alt | removealt)
 213 | 			shift
 214 | 			do_update_alternatives "--remove" "$@"
 215 | 			;;
 216 | 		rm-group | rmgroup | rm-grp | rmgrp | remove-group | removegroup | remove-grp | removegrp)
 217 | 			shift
 218 | 			do_update_alternatives "--remove-all" "$@"
 219 | 			;;
 220 | 		rm-child | rmchild | remove-child | removechild)
 221 | 			shift
 222 | 			do_update_alternatives "--remove-slave" "$@"
 223 | 			;;
 224 | 		#
 225 | 		# update-alternatives pass-through
 226 | 		#
 227 | 		display | list | set | auto)
 228 | 			local cmd="${1}"
 229 | 			shift
 230 | 			do_update_alternatives "--${cmd}" "$@"
 231 | 			;;
 232 | 		#
 233 | 		# update-alternatives helpers
 234 | 		#
 235 | 		ua)
 236 | 			shift
 237 | 			do_update_alternatives "$@"
 238 | 			;;
 239 | 		ua-help)
 240 | 			shift
 241 | 			command update-alternatives --help "$@"
 242 | 			;;
 243 | 		ua-version)
 244 | 			shift
 245 | 			command update-alternatives --version "$@"
 246 | 			;;
 247 | 		*)
 248 | 			if [ -z "${1:-}" ]; then
 249 | 				printf "usage: my-alternatives <command> [option ...]\n" >&2
 250 | 			else
 251 | 				printf "error: unrecognized command: %s\n" "${1}" >&2
 252 | 			fi
 253 | 			printf "\nsee 'my-alternatives --help' for list of commands\n" >&2
 254 | 			exit 2
 255 | 			;;
 256 | 	esac
 257 | }
 258 | 
 259 | function help_init() {
 260 | 	cat <<-'USAGE'
 261 | 		usage: eval "$( my-alternatives <init | shellenv> [--shell <shell>] [--admin-dir <system_admin_dir>] [--alt-dir <system_alt_dir>] [alt_home] )"
 262 | 
 263 | 		  prepares the current shell session for user-level alternatives.
 264 | 
 265 | 		  if [alt_home] is provided, it will be configured as MY_ALTS_HOME
 266 | 
 267 | 		  when [alt_home] is NOT provided, the following logic will be used determine MY_ALTS_HOME:
 268 | 
 269 | 		    * check if $MY_ALTS_HOME already defined
 270 | 		    * check $XDG_CONFIG_HOME. if present, use $XDG_CONFIG_HOME/my-alternatives
 271 | 		    * finally default to ~/.config/my-alternatives
 272 | 
 273 | 		  if [--admin-dir <system_admin_dir>] is provided, it will be configured as MY_ALTS_SYS_ADMIN_DIR
 274 | 
 275 | 		  when [--admin-dir <system_admin_dir>] is NOT provided, the following logic will be used to determine MY_ALTS_SYS_ADMIN_DIR:
 276 | 
 277 | 		    * check if $MY_ALTS_SYS_ADMIN_DIR already defined
 278 | 		    * finally default to /var/lib/alternatives
 279 | 
 280 | 		  if [--alt-dir <system_alt_dir>] is provided, it will be configured as MY_ALTS_SYS_ALT_DIR
 281 | 
 282 | 		  when [--alt-dir <system_alt_dir>] is NOT provided, the following logic will be used to determine MY_ALTS_SYS_ALT_DIR:
 283 | 
 284 | 		    * check if $MY_ALTS_SYS_ALT_DIR already defined
 285 | 		    * finally default to /etc/alternatives
 286 | 
 287 | 		  when [--shell <shell>] is NOT provided, checks $SHELL.
 288 | 
 289 | 		  NOTE: Currently only 'bash' is supported.
 290 | 
 291 | 		  creates the MY_ALTS_HOME directory and required sub-directories if they don't already exist.
 292 | 
 293 | 		  finally, configures PATH and MANPATH.
 294 | 
 295 | 		example:
 296 | 
 297 | 		  # prepare shell with default MY_ALTS_HOME logic
 298 | 		  # NOTE: you can place this in your .profile
 299 | 		  $ eval "$( command my-alternatives init )"
 300 | 
 301 | 		  # <ALT_HOME> = ~/.config/my-alternatives
 302 | 		  export MY_ALTS_HOME="<ALT_HOME>"
 303 | 		  export PATH="<ALT_HOME>/bin${PATH:+:$PATH}"
 304 | 		  export MANPATH="<ALT_HOME>/man:${MANPATH:-}"
 305 | 		  export MY_ALTS_SYS_ADMIN_DIR=/var/lib/alternatives
 306 | 		  export MY_ALTS_SYS_ALT_DIR=/etc/alternatives
 307 | 
 308 | 		more info:
 309 | 
 310 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 311 | 
 312 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 313 | 
 314 | 	USAGE
 315 | 	exit 2
 316 | }
 317 | 
 318 | function do_init() {
 319 | 	local alt_home shell admin_dir alt_dir
 320 | 	while (($#)); do
 321 | 		case "${1}" in
 322 | 			--shell)
 323 | 				if [ -z "${2:-}" ]; then
 324 | 					printf "my-alternatives: error: no value provided for --shell option. see 'my-alternatives help init' for usage\n" >&2
 325 | 					exit 2
 326 | 				fi
 327 | 				# basename as a courtesy in case they use $SHELL/etc
 328 | 				#
 329 | 				shell="$(basename "${2}")"
 330 | 				shift 2
 331 | 				;;
 332 | 			--admin-dir)
 333 | 				if [ -z "${2:-}" ]; then
 334 | 					printf "my-alternatives: error: no value provided for --admin-dir option. see 'my-alternatives help init' for usage\n" >&2
 335 | 					exit 2
 336 | 				fi
 337 | 				admin_dir="${2}"
 338 | 				shift 2
 339 | 				;;
 340 | 			--alt-dir)
 341 | 				if [ -z "${2:-}" ]; then
 342 | 					printf "my-alternatives: error: no value provided for --alt-dir option. see 'my-alternatives help init' for usage\n" >&2
 343 | 					exit 2
 344 | 				fi
 345 | 				alt_dir="${2}"
 346 | 				shift 2
 347 | 				;;
 348 | 			*)
 349 | 				# If alt_home already defined
 350 | 				#
 351 | 				if [ -n "${alt_home:-}" ]; then
 352 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help init' for usage\n" "${1}" >&2
 353 | 					exit 2
 354 | 				fi
 355 | 				alt_home="${1}"
 356 | 				shift
 357 | 				;;
 358 | 		esac
 359 | 	done
 360 | 	# If --shell not provided, check $SHELL
 361 | 	#
 362 | 	if [ -z "${shell:-}" ]; then
 363 | 		shell="$(basename "${SHELL:-}")"
 364 | 		if [ -z "${shell}" ]; then
 365 | 			printf "my-alternatives: error: Unable to determine shell.  see 'my-alternatives help init' for usage\n" >&2
 366 | 			exit 2
 367 | 		fi
 368 | 	fi
 369 | 	# Confirm shell supported
 370 | 	#
 371 | 	if [[ "${shell}" != "bash" ]]; then
 372 | 		printf "my-alternatives: error: unrecognized shell: %s.  see 'my-alternatives help init' for usage\n" "${shell}" >&2
 373 | 		exit 2
 374 | 	fi
 375 | 	#
 376 | 	# set from specified values or default logic
 377 | 	#
 378 | 	MY_ALTS_HOME="${alt_home:-${MY_ALTS_HOME:-${XDG_CONFIG_HOME:-${HOME:?}/.config}/my-alternatives}}"
 379 | 	MY_ALTS_SYS_ADMIN_DIR="${admin_dir:-${MY_ALTS_SYS_ADMIN_DIR:-/var/lib/alternatives}}"
 380 | 	MY_ALTS_SYS_ALT_DIR="${alt_dir:-${MY_ALTS_SYS_ALT_DIR:-/etc/alternatives}}"
 381 | 	# print assignments seperately as I don't want to escape ALL the other $ :)
 382 | 	#
 383 | 	printf '_MY_ALTS_HOME="%s"\n' "${MY_ALTS_HOME:?}"
 384 | 	printf '_MY_ALTS_SYS_ADMIN_DIR="%s"\n' "${MY_ALTS_SYS_ADMIN_DIR:?}"
 385 | 	printf '_MY_ALTS_SYS_ALT_DIR="%s"\n' "${MY_ALTS_SYS_ALT_DIR:?}"
 386 | 	# path clean up adapted from: https://stackoverflow.com/a/2108540/1822537
 387 | 	#
 388 | 	cat <<-'INIT'
 389 | 		if [ -n "${_MY_ALTS_HOME}:-" ] && command mkdir -p -- "${_MY_ALTS_HOME}"; then
 390 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/bin"
 391 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/man"
 392 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/man/man"{1..9}
 393 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/admin"
 394 | 		    command mkdir -p -- "${_MY_ALTS_HOME}/alts"
 395 | 		    # clean up PATH and add to front
 396 | 		    PATH=":${PATH:-}:"
 397 | 		    PATH="${PATH/":${_MY_ALTS_HOME}/bin:"/:}"
 398 | 		    PATH="${PATH%:}"
 399 | 		    PATH="${PATH#:}"
 400 | 		    PATH="${_MY_ALTS_HOME}/bin${PATH:+:$PATH}"
 401 | 		    # clean up MANPATH and add to front
 402 | 		    MANPATH=":${MANPATH:-}:"
 403 | 		    MANPATH="${MANPATH/":${_MY_ALTS_HOME}/man:"/:}"
 404 | 		    MANPATH="${MANPATH%:}"
 405 | 		    MANPATH="${MANPATH#:}"
 406 | 		    MANPATH="${_MY_ALTS_HOME}/man:${MANPATH:-}"
 407 | 		    # add helper function
 408 | 		    my-alternatives() {
 409 | 		        case "${1:-}" in
 410 | 		            # some commands require eval
 411 | 		            init     | shellenv  | \
 412 | 		            init-tmp | init-temp | tmp   | temp   | \
 413 | 		            rm-tmp   | rm-temp   | rmtmp | rmtemp | remove-tmp | remove-temp | removetmp | removetemp)
 414 | 		                eval "$( command my-alternatives "$@" )"
 415 | 		                ;;
 416 | 		            *)
 417 | 		            command my-alternatives "$@"
 418 | 		                ;;
 419 | 		        esac
 420 | 		    }
 421 | 		    # finally, export variables
 422 | 		    command export MY_ALTS_HOME="${_MY_ALTS_HOME}"
 423 | 		    command export MY_ALTS_SYS_ADMIN_DIR="${_MY_ALTS_SYS_ADMIN_DIR}"
 424 | 		    command export MY_ALTS_SYS_ALT_DIR="${_MY_ALTS_SYS_ALT_DIR}"
 425 | 		fi
 426 | 		command unset _MY_ALTS_HOME
 427 | 		command unset _MY_ALTS_SYS_ADMIN_DIR
 428 | 		command unset _MY_ALTS_SYS_ALT_DIR
 429 | 	INIT
 430 | }
 431 | 
 432 | function help_init_tmp() {
 433 | 	cat <<-'USAGE'
 434 | 		usage: my-alternatives <init-tmp | tmp> [tmp_dir]
 435 | 
 436 | 		  configures the current shell session for temporary (short-lived) changes.
 437 | 
 438 | 		  if [tmp_dir] is provided, it will be configured as MY_ALTS_TMP
 439 | 
 440 | 		  when [tmp_dir] is NOT provided, the following logic will be used determine MY_ALTS_TMP:
 441 | 
 442 | 		    * check if $MY_ALTS_TMP already defined
 443 | 		    * check XDG_CACHE_HOME. if present, use XDG_CACHE_HOME/my-alternatives/<RANDOM>
 444 | 		    * finally default to ~/.config/my-alternatives/<RANDOM>
 445 | 
 446 | 		  creates the MY_ALTS_TMP directory and required sub-directories if they don't already exist.
 447 | 
 448 | 		  finally, configures PATH and MANPATH.
 449 | 
 450 | 		example:
 451 | 
 452 | 		  $ my-alternatives init-tmp
 453 | 
 454 | 		  # <ALT_TMP> = ~/.config/my-alternatives/abcd123
 455 | 		  export MY_ALTS_TMP="<ALT_TMP>"
 456 | 		  export PATH="<ALT_TMP>/bin${PATH:+:$PATH}"
 457 | 		  export MANPATH="<ALT_TMP>/man:${MANPATH:-}"
 458 | 
 459 | 		more info:
 460 | 
 461 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 462 | 
 463 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 464 | 
 465 | 	USAGE
 466 | 	exit 2
 467 | }
 468 | 
 469 | function do_init_tmp() {
 470 | 	# Ensure alt_home configured
 471 | 	#
 472 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 473 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 474 | 		exit 2
 475 | 	fi
 476 | 	local alt_tmp
 477 | 	while (($#)); do
 478 | 		case "${1}" in
 479 | 			*)
 480 | 				# If alt_root already defined
 481 | 				#
 482 | 				if [ -n "${alt_tmp:-}" ]; then
 483 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help init-tmp' for usage\n" "${1}" >&2
 484 | 					exit 2
 485 | 				fi
 486 | 				alt_tmp="${1}"
 487 | 				shift
 488 | 				;;
 489 | 		esac
 490 | 	done
 491 | 	# create temp folder if no alt_tmp or MY_ALTS_TMP given
 492 | 	#
 493 | 	MY_ALTS_TMP="${alt_tmp:-${MY_ALTS_TMP:-}}"
 494 | 	if [ -z "${MY_ALTS_TMP}" ]; then
 495 | 		while :; do
 496 | 			MY_ALTS_TMP="${XDG_CACHE_HOME:-"${HOME:?}/.cache"}/my-alternatives/${RANDOM}${RANDOM}"
 497 | 			[ -d "${MY_ALTS_TMP}" ] || break
 498 | 		done
 499 | 	fi
 500 | 	# print assignment seperately as I don't want to escape ALL the other $ :)
 501 | 	#
 502 | 	printf '_MY_ALTS_TMP="%s"\n' "${MY_ALTS_TMP:?}"
 503 | 	cat <<-'TMP'
 504 | 		if [ -n "${_MY_ALTS_TMP}:-" ] && command mkdir -p -- "${_MY_ALTS_TMP}"; then
 505 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/bin"
 506 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/man"
 507 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/man/man"{1..9}
 508 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/admin"
 509 | 		    command mkdir -p -- "${_MY_ALTS_TMP}/alts"
 510 | 		    # clean up PATH and add to front
 511 | 		    PATH=":${PATH:-}:"
 512 | 		    PATH="${PATH/":${_MY_ALTS_TMP}/bin:"/:}"
 513 | 		    PATH="${PATH%:}"
 514 | 		    PATH="${PATH#:}"
 515 | 		    PATH="${_MY_ALTS_TMP}/bin${PATH:+:$PATH}"
 516 | 		    # clean up MANPATH and add to front
 517 | 		    MANPATH=":${MANPATH:-}:"
 518 | 		    MANPATH="${MANPATH/":${_MY_ALTS_TMP}/man:"/:}"
 519 | 		    MANPATH="${MANPATH%:}"
 520 | 		    MANPATH="${MANPATH#:}"
 521 | 		    MANPATH="${_MY_ALTS_TMP}/man:${MANPATH:-}"
 522 | 		    # finally, export tmp variable
 523 | 		    command export MY_ALTS_TMP="${_MY_ALTS_TMP}"
 524 | 		fi
 525 | 		command unset _MY_ALTS_TMP
 526 | 	TMP
 527 | }
 528 | 
 529 | function help_rm_tmp() {
 530 | 	cat <<-'USAGE'
 531 | 		usage: my-alternatives rm-tmp
 532 | 
 533 | 		  removes the temporary configuration from the current shell session.
 534 | 
 535 | 		  restores the curent session to the default user-level alternatives.
 536 | 
 537 | 		  removes the temporary directory referenced by MY_ALTS_TMP
 538 | 
 539 | 		  removes MY_ALTS_TMP from both PATH and MANPATH
 540 | 
 541 | 		  finall, unsets the MY_ALTS_TMP variable
 542 | 
 543 | 		more info:
 544 | 
 545 | 		  see 'my-alternatives --help' to learn more about creating a temporary configuration.
 546 | 
 547 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 548 | 
 549 | 	USAGE
 550 | 	exit 2
 551 | }
 552 | 
 553 | function do_rm_tmp() {
 554 | 	# Ensure alt_home configured
 555 | 	#
 556 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 557 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 558 | 		exit 2
 559 | 	fi
 560 | 	# No further arguments expected
 561 | 	#
 562 | 	if [[ $# -gt 0 ]]; then
 563 | 		printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help rm-tmp' for usage\n" "${1}" >&2
 564 | 		exit 2
 565 | 	fi
 566 | 	cat <<-'RMTMP'
 567 | 		if [ -n "${MY_ALTS_TMP:-}" ]; then
 568 | 		    # clean up temp dir
 569 | 		    if [ -d "${MY_ALTS_TMP}" ]; then
 570 | 		        command rm -rf "${MY_ALTS_TMP}/"
 571 | 		    fi
 572 | 		    # clean up PATH
 573 | 		    PATH=":${PATH:-}:"
 574 | 		    PATH="${PATH/":${MY_ALTS_TMP}/bin:"/:}"
 575 | 		    PATH="${PATH%:}"
 576 | 		    PATH="${PATH#:}"
 577 | 		    # clean up MANPATH
 578 | 		    MANPATH=":${MANPATH:-}:"
 579 | 		    MANPATH="${MANPATH/":${MY_ALTS_TMP}/man:"/:}"
 580 | 		    MANPATH="${MANPATH%:}"
 581 | 		    MANPATH="${MANPATH#:}"
 582 | 		fi
 583 | 		# finally, clean up tmp variable
 584 | 		command unset MY_ALTS_TMP
 585 | 	RMTMP
 586 | }
 587 | 
 588 | function help_import() {
 589 | 	cat <<-'USAGE'
 590 | 		usage: my-alternatives import <name>
 591 | 
 592 | 		  imports an alternative group into the currently-configured alternatives.
 593 | 
 594 | 		  when the default alternatives (ie. MY_ALTS_HOME) are active:
 595 | 		    * tries to import from the system-level alternatives
 596 | 
 597 | 		  when temporary alternatives (i.e MY_ALTS_TMP) are active:
 598 | 		    * first tries to import from the default alternatives
 599 | 		    * finally tries to import from the system-level alternatives
 600 | 
 601 | 		more info:
 602 | 
 603 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 604 | 
 605 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
 606 | 
 607 | 	USAGE
 608 | 	exit 2
 609 | }
 610 | 
 611 | function do_import() {
 612 | 	# Ensure alt_home configured
 613 | 	#
 614 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 615 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 616 | 		exit 2
 617 | 	fi
 618 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
 619 | 	local name
 620 | 	while (($#)); do
 621 | 		case "${1}" in
 622 | 			*)
 623 | 				# If name already defined
 624 | 				#
 625 | 				if [ -n "${name:-}" ]; then
 626 | 					printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help import' for usage\n" "${1}" >&2
 627 | 					exit 2
 628 | 				fi
 629 | 				name="${1}"
 630 | 				shift
 631 | 				;;
 632 | 		esac
 633 | 	done
 634 | 	# No name argument
 635 | 	#
 636 | 	if [[ -z "${name:-}" ]]; then
 637 | 		printf "my-alternatives: error: no name provided. see 'my-alternatives help import' for usage\n" >&2
 638 | 		exit 1
 639 | 	fi
 640 | 	local from # for status message
 641 | 	local data_file
 642 | 	local admin_dir alt_dir
 643 | 	# If tmp is active try import from home
 644 | 	#
 645 | 	if [ "${alt_root}" = "${MY_ALTS_TMP:-}" ]; then
 646 | 		admin_dir="${MY_ALTS_HOME}/admin"
 647 | 		alt_dir="${MY_ALTS_HOME}/alts"
 648 | 		data_file="${admin_dir}/${name}"
 649 | 
 650 | 		if [ -s "${data_file}" ]; then
 651 | 			from="MY_ALTS_HOME: ${MY_ALTS_HOME}" # for status message
 652 | 		fi
 653 | 	fi
 654 | 	if [ -z "${from:-}" ]; then
 655 | 		# final fallback = update-alternatives default
 656 | 		admin_dir="${MY_ALTS_SYS_ADMIN_DIR:-}"
 657 | 		alt_dir="${MY_ALTS_SYS_ALT_DIR:-}"
 658 | 		data_file="${admin_dir}/${name}"
 659 | 
 660 | 		if [ -s "${data_file}" ]; then
 661 | 			from="system-level alternative" # for status message
 662 | 		fi
 663 | 	fi
 664 | 	# final sanity check
 665 | 	#
 666 | 	if [ -z "${from:-}" ]; then
 667 | 		printf "my-alternatives: error: unable to locate alternative group with name %s\n" "${name}" >&2
 668 | 		exit 2
 669 | 	fi
 670 | 
 671 | 	alt_parse_admin_redhat "${data_file}" || return $?
 672 | 
 673 | 	if [ -z "${ALT_GROUP_LINK}" ]; then
 674 | 		printf "my-alternatives: error: unable to determine provided location\n" >&2
 675 | 		exit 2
 676 | 	fi
 677 | 
 678 | 	# Fill in NAME
 679 | 	#
 680 | 	local ALT_GROUP_NAME="${name}"
 681 | 	# Fill in CURRENT_VALUE
 682 | 	# NOTE: Assumes knowledge of the configuration's "alt" directory
 683 | 	#
 684 | 	local ALT_GROUP_CURRENT_VALUE
 685 | 	if [ -e "${alt_dir}/${name}" ] && [ -L "${alt_dir}/${name}" ]; then
 686 | 		ALT_GROUP_CURRENT_VALUE=$(command readlink "${alt_dir}/${name}")
 687 | 	fi
 688 | 	: "${ALT_GROUP_CURRENT_VALUE:=none}"
 689 | 
 690 | 	printf "importing alternative group %s%s from %s\n" "${ALT_GROUP_NAME}" "${ALT_GROUP_STATUS:+" in ${ALT_GROUP_STATUS} mode"}" "${from}"
 691 | 
 692 | 	local alt_group_link_rel
 693 | 	alt_group_link_rel="$(get_my_alt_rel_path "${ALT_GROUP_LINK}")"
 694 | 	if [ "${alt_group_link_rel}" == "${ALT_GROUP_LINK}" ]; then
 695 | 		printf "my-alternatives: error: unable to determine relative path for primary link: %s\n" "${ALT_GROUP_LINK}" >&2
 696 | 		exit 2
 697 | 	fi
 698 | 	ALT_GROUP_LINK="${alt_root}${alt_group_link_rel}"
 699 | 	local a=0
 700 | 	while [[ $a -lt ${#ALT_GROUP_VALUES[@]} ]]; do
 701 | 		local alt_value="${ALT_GROUP_VALUES[$a]}"
 702 | 		local alt_priority="${ALT_GROUP_PRIORITIES[$a]}"
 703 | 		local alt_family="${ALT_GROUP_FAMILIES[$a]}"
 704 | 		local alt_init_script="${ALT_GROUP_INIT_SCRIPTS[$a]}"
 705 | 		local child_args=()
 706 | 		local s=0
 707 | 		while [[ $s -lt ${#ALT_GROUP_SLAVE_NAMES[@]} ]]; do
 708 | 			local child_name="${ALT_GROUP_SLAVE_NAMES[$s]}"
 709 | 			local child_link="${ALT_GROUP_SLAVE_LINKS[$s]}"
 710 | 			local child_link_rel
 711 | 			child_link_rel="$(get_my_alt_rel_path "${child_link}")"
 712 | 			if [ "${child_link_rel}" == "${child_link}" ]; then
 713 | 				printf " !!! warning: Unable to determine type (bin/man/etc) for %s\n" "${child_name} @ ${child_link} - skipping" >&2
 714 | 			else
 715 | 				child_link="${alt_root}${child_link_rel}"
 716 | 				local child_value_ref="ALT_GROUP_VALUE_${a}_SLAVE_${s}_VALUE"
 717 | 				local child_value="${!child_value_ref}"
 718 | 				# Did we find a child value?
 719 | 				#
 720 | 				if [[ -n "${child_value}" ]]; then
 721 | 					child_args+=("--slave" "${child_link}" "${child_name}" "${child_value}")
 722 | 				else
 723 | 					printf " !!! warning: Unable to determine type (bin/man/etc) for %s\n" "${child_name} @ ${child_link} - skipping" >&2
 724 | 				fi
 725 | 			fi
 726 | 			((s += 1))
 727 | 		done
 728 | 
 729 | 		printf " ... importing alternative %s with priority %s\n" "${alt_value}" "${alt_priority}"
 730 | 		command update-alternatives \
 731 | 			--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 732 | 			--install "${ALT_GROUP_LINK}" "${ALT_GROUP_NAME}" "${alt_value}" "${alt_priority}" \
 733 | 			${alt_family:+--family "${alt_family}"} \
 734 | 			${alt_init_script:+--initscript "${alt_init_script}"} \
 735 | 			"${child_args[@]}" \
 736 | 			>/dev/null || return $?
 737 | 
 738 | 		((a += 1))
 739 | 	done
 740 | 	# Set current value if manual mode
 741 | 	#
 742 | 	if [ "${ALT_GROUP_STATUS}" = "manual" ] && [ ! "${ALT_GROUP_CURRENT_VALUE:-none}" = "none" ]; then
 743 | 		printf " ... marking %s as active alternative\n" "${ALT_GROUP_CURRENT_VALUE}"
 744 | 		command update-alternatives \
 745 | 			--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 746 | 			--set "${ALT_GROUP_NAME}" "${ALT_GROUP_CURRENT_VALUE}" \
 747 | 			>/dev/null || return $?
 748 | 	fi
 749 | 	# finished
 750 | 	printf "\n"
 751 | }
 752 | 
 753 | function help_add() {
 754 | 	cat <<-'USAGE'
 755 | 		usage: my-alternatives add <group-name> <group-path> <alt-path> <alt-priority> [--family <family>] [--init-script <service>] [--child <group-name> <group-path> <alt-path>]...
 756 | 
 757 | 		  adds an alternative to a group within the currently-configured alternatives.
 758 | 		  The group is created if it does not already exist.
 759 | 
 760 | 		  NOTE: This is generally a pass-through to 'update-alternatives --install', BUT the argument syntax is slightly diffrent:
 761 | 
 762 | 		    * the order of <group-name> and <group-path> arguments are inverted
 763 | 		    * uses --child (vs --slave) for secondary files
 764 | 		    * uses --init-script (vs --initscript) for service option
 765 | 		    * <group-path> arguments should be relative
 766 | 		        ex: bin/pager
 767 | 		        ex: man/man1/pager.1.gz
 768 | 
 769 | 		options:
 770 | 
 771 | 		  <group-name>
 772 | 		     the name of the alternative group.
 773 | 		     used when referring to the group in other commands.
 774 | 		     the name must be unique within the currently-configured alternatives.
 775 | 		     ex: pager
 776 | 		     ex: pager.1.gz
 777 | 
 778 | 		  <group-path>
 779 | 		     path provided by the group.
 780 | 		     path should be relative.
 781 | 		     ex: bin/pager
 782 | 		     ex: man/man1/pager.1.gz
 783 | 
 784 | 		  <alt-path>
 785 | 		     the path of the alternative being introduced.
 786 | 		     ex: /usr/bin/less
 787 | 		     ex: /usr/share/man/man1/less.1.gz
 788 | 
 789 | 		  <alt-priority>
 790 | 		     priority of this alternative.
 791 | 		     alternatives with larger values have higher priority in automatic mode.
 792 | 
 793 | 		  --family <family>
 794 | 		    can be used to group similar alternatives.
 795 | 		    is a Red Hat Linux specific option.
 796 | 
 797 | 		  --init-script <service>
 798 | 		    when used, service will be associated with the alternative via chkconfig.
 799 | 		    is a Red Hat Linux specific option.
 800 | 
 801 | 		  --child <group-name> <group-path> <alt-path>
 802 | 		     adds a secondary entry.
 803 | 		     optional, but if given, all arguments are required.
 804 | 
 805 | 		more info:
 806 | 
 807 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 808 | 
 809 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--install' command.
 810 | 
 811 | 	USAGE
 812 | 	exit 2
 813 | }
 814 | 
 815 | function do_add() {
 816 | 	# Ensure alt_home configured
 817 | 	#
 818 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
 819 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
 820 | 		exit 2
 821 | 	fi
 822 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
 823 | 	# Build update-alternatives --install args
 824 | 	#
 825 | 	local args=("--install")
 826 | 	local providing_name providing_path
 827 | 	# primary group-name
 828 | 	#
 829 | 	if [ -z "${1:-}" ]; then
 830 | 		printf "my-alternatives: error: primary group-name not provided. see 'my-alternatives help add' for usage\n" >&2
 831 | 		exit 1
 832 | 	fi
 833 | 	providing_name="${1}"
 834 | 	shift
 835 | 	# primary group-path
 836 | 	#
 837 | 	if [ -z "${1:-}" ]; then
 838 | 		printf "my-alternatives: error: primary group-path not provided. see 'my-alternatives help add' for usage\n" >&2
 839 | 		exit 1
 840 | 	fi
 841 | 	if [[ "${1}" =~ ^/(bin|man)/ ]]; then
 842 | 		providing_path="${alt_root}${1}"
 843 | 	elif [[ "${1}" =~ ^(bin|man)/ ]]; then
 844 | 		providing_path="${alt_root}/${1}"
 845 | 	else
 846 | 		local group_path
 847 | 		group_path="$(get_my_alt_rel_path "${1}")"
 848 | 		if [ "${group_path}" == "${1}" ]; then
 849 | 			printf "my-alternatives: error: unable to determine relative path for group-path: %s\n" "${group_path}" >&2
 850 | 			exit 2
 851 | 		fi
 852 | 		providing_path="${alt_root}${group_path}"
 853 | 	fi
 854 | 	shift
 855 | 
 856 | 	# add to args (inverted)
 857 | 	args+=("${providing_path}" "${providing_name}")
 858 | 
 859 | 	# primary alt-path
 860 | 	#
 861 | 	if [ -z "${1:-}" ]; then
 862 | 		printf "my-alternatives: error: primary alt-path not provided. see 'my-alternatives help add' for usage\n" >&2
 863 | 		exit 1
 864 | 	fi
 865 | 	args+=("${1}")
 866 | 	shift
 867 | 	# alt-priority
 868 | 	#
 869 | 	if [ -z "${1:-}" ]; then
 870 | 		printf "my-alternatives: error: alt-priority not provided. see 'my-alternatives help install' for usage\n" >&2
 871 | 		exit 1
 872 | 	fi
 873 | 	args+=("${1}")
 874 | 	shift
 875 | 	# family, init-script, children
 876 | 	#
 877 | 	while (($#)); do
 878 | 		case "${1}" in
 879 | 			--family)
 880 | 				shift
 881 | 				if [ -z "${1:-}" ]; then
 882 | 					printf "my-alternatives: error: no value provided for --family option. see 'my-alternatives help add' for usage\n" >&2
 883 | 					exit 2
 884 | 				fi
 885 | 				args+=("--family" "${1}")
 886 | 				shift
 887 | 				;;
 888 | 			--init-script)
 889 | 				shift
 890 | 				if [ -z "${1:-}" ]; then
 891 | 					printf "my-alternatives: error: no value provided for --init-script option. see 'my-alternatives help add' for usage\n" >&2
 892 | 					exit 2
 893 | 				fi
 894 | 				args+=("--initscript" "${1}")
 895 | 				shift
 896 | 				;;
 897 | 			--child)
 898 | 				args+=("--slave")
 899 | 				shift
 900 | 				# secondary group-name
 901 | 				#
 902 | 				if [ -z "${1:-}" ]; then
 903 | 					printf "my-alternatives: error: secondary group-name not provided. see 'my-alternatives help add' for usage\n" >&2
 904 | 					exit 1
 905 | 				fi
 906 | 				providing_name="${1}"
 907 | 				shift
 908 | 				# secondary group-path
 909 | 				#
 910 | 				if [ -z "${1:-}" ]; then
 911 | 					printf "my-alternatives: error: secondary group-path not provided. see 'my-alternatives help add' for usage\n" >&2
 912 | 					exit 1
 913 | 				fi
 914 | 				if [[ "${1}" =~ ^/(bin|man)/ ]]; then
 915 | 					providing_path="${alt_root}${1}"
 916 | 				elif [[ "${1}" =~ ^(bin|man)/ ]]; then
 917 | 					providing_path="${alt_root}/${1}"
 918 | 				else
 919 | 					local group_path
 920 | 					group_path="$(get_my_alt_rel_path "${1}")"
 921 | 					if [ "${group_path}" == "${1}" ]; then
 922 | 						printf "my-alternatives: error: unable to determine relative path for group-path: %s\n" "${group_path}" >&2
 923 | 						exit 2
 924 | 					fi
 925 | 					providing_path="${alt_root}${group_path}"
 926 | 				fi
 927 | 				shift
 928 | 
 929 | 				# add to args (inverted)
 930 | 				args+=("${providing_path}" "${providing_name}")
 931 | 
 932 | 				# secondary alt-path
 933 | 				#
 934 | 				if [ -z "${1:-}" ]; then
 935 | 					printf "my-alternatives: error: secondary alt-path not provided. see 'my-alternatives help add' for usage\n" >&2
 936 | 					exit 1
 937 | 				fi
 938 | 				args+=("${1}")
 939 | 				shift
 940 | 				;;
 941 | 			*)
 942 | 				printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help add' for usage\n" "${1}" >&2
 943 | 				exit 2
 944 | 				;;
 945 | 		esac
 946 | 	done
 947 | 
 948 | 	command update-alternatives \
 949 | 		--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
 950 | 		"${args[@]}" \
 951 | 		>/dev/null || return $?
 952 | }
 953 | 
 954 | function help_add_child() {
 955 | 	cat <<-'USAGE'
 956 | 		usage: my-alternatives add-child <group-name> <alt-path> <child-name> <child-group-path> <child-alt-path>
 957 | 
 958 | 		  adds a child to an existing alternative for a group within the current configuration.
 959 | 
 960 | 		  NOTE: This is generally a pass-through to 'update-alternatives --add-slave', BUT the argument syntax is slightly diffrent:
 961 | 
 962 | 		    * the order of <child_name> and <child_group_path> arguments are inverted
 963 | 		    * <child-group-path> should be relative
 964 | 		        ex: man/man1/pager.1.gz
 965 | 
 966 | 		options:
 967 | 
 968 | 		  <group-name>
 969 | 		     the name of the alternative group.
 970 | 		     ex: pager
 971 | 
 972 | 		  <alt-path>
 973 | 		     the primary path identifying which alternative to add the child to.
 974 | 		     ex: /usr/bin/less
 975 | 
 976 | 		  <child-name>
 977 | 		     the name of the child entry within the alternative group.
 978 | 		     ex: pager.1.gz
 979 | 
 980 | 		  <child-group-path>
 981 | 		    path provided by the alternative group child entry
 982 | 		    ex: man/man1/pager.1.gz
 983 | 
 984 | 		  <child-alt-path>
 985 | 		    the path of the alternative child entry being introduced
 986 | 		    ex: /usr/share/man/man1/less.1.gz
 987 | 
 988 | 		more info:
 989 | 
 990 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
 991 | 
 992 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--add-slave' command.
 993 | 
 994 | 	USAGE
 995 | }
 996 | 
 997 | function do_add_child() {
 998 | 	# Ensure alt_home configured
 999 | 	#
1000 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
1001 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
1002 | 		exit 2
1003 | 	fi
1004 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
1005 | 	# Build update-alternatives --add-slave args
1006 | 	#
1007 | 	local args=("--add-slave")
1008 | 	local providing_name providing_path
1009 | 	# primary group-name
1010 | 	#
1011 | 	if [ -z "${1:-}" ]; then
1012 | 		printf "my-alternatives: error: <group-name> not provided. see 'my-alternatives help add-child' for usage\n" >&2
1013 | 		exit 1
1014 | 	fi
1015 | 	args+=("${1}")
1016 | 	shift
1017 | 	# primary alt path
1018 | 	#
1019 | 	if [ -z "${1:-}" ]; then
1020 | 		printf "my-alternatives: error: <alt-path> not provided. see 'my-alternatives help add-child' for usage\n" >&2
1021 | 		exit 1
1022 | 	fi
1023 | 	args+=("${1}")
1024 | 	shift
1025 | 	# child group name
1026 | 	#
1027 | 	if [ -z "${1:-}" ]; then
1028 | 		printf "my-alternatives: error: <child-name> not provided. see 'my-alternatives help add-child' for usage\n" >&2
1029 | 		exit 1
1030 | 	fi
1031 | 	providing_name="${1}"
1032 | 	shift
1033 | 	# child group path
1034 | 	#
1035 | 	if [ -z "${1:-}" ]; then
1036 | 		printf "my-alternatives: error: <child-group-path> not provided. see 'my-alternatives help add-child' for usage\n" >&2
1037 | 		exit 1
1038 | 	fi
1039 | 	if [[ "${1}" =~ ^/(bin|man)/ ]]; then
1040 | 		providing_path="${alt_root}${1}"
1041 | 	elif [[ "${1}" =~ ^(bin|man)/ ]]; then
1042 | 		providing_path="${alt_root}/${1}"
1043 | 	else
1044 | 		local group_path
1045 | 		group_path="$(get_my_alt_rel_path "${1}")"
1046 | 		if [ "${group_path}" == "${1}" ]; then
1047 | 			printf "my-alternatives: error: unable to determine relative path for <child-group-path>>: %s\n" "${group_path}" >&2
1048 | 			exit 2
1049 | 		fi
1050 | 		providing_path="${alt_root}${group_path}"
1051 | 	fi
1052 | 	shift
1053 | 
1054 | 	# add to args (inverted)
1055 | 	args+=("${providing_path}" "${providing_name}")
1056 | 
1057 | 	# child alt path
1058 | 	#
1059 | 	if [ -z "${1:-}" ]; then
1060 | 		printf "my-alternatives: error: <child-alt-path> not provided. see 'my-alternatives help add-child' for usage\n" >&2
1061 | 		exit 1
1062 | 	fi
1063 | 	args+=("${1}")
1064 | 	shift
1065 | 
1066 | 	# No further arguments expected
1067 | 	#
1068 | 	if [[ $# -gt 0 ]]; then
1069 | 		printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help add-child' for usage\n" "${1}" >&2
1070 | 		exit 2
1071 | 	fi
1072 | 
1073 | 	command update-alternatives \
1074 | 		--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
1075 | 		"${args[@]}" \
1076 | 		>/dev/null || return $?
1077 | }
1078 | 
1079 | function help_select() {
1080 | 	cat <<-'USAGE'
1081 | 		usage: my-alternatives <select | config> <name>
1082 | 
1083 | 		  shows alternatives for the group <name> and asks the user to select which one to use.
1084 | 
1085 | 		  calls 'import <name>' if the group is not present in the currently-configured alternatives.
1086 | 
1087 | 		more info:
1088 | 
1089 | 		  see 'my-alternatives --help' to learn more about the 'import' command.
1090 | 
1091 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--config' command.
1092 | 
1093 | 	USAGE
1094 | 	exit 2
1095 | }
1096 | 
1097 | function do_select() {
1098 | 	# Ensure alt_home configured
1099 | 	#
1100 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
1101 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
1102 | 		exit 2
1103 | 	fi
1104 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
1105 | 	# No name argument
1106 | 	#
1107 | 	if [[ -z "${1:-}" ]]; then
1108 | 		printf "my-alternatives: error: no name provided. see 'my-alternatives help select' for usage\n" >&2
1109 | 		exit 1
1110 | 	fi
1111 | 	local name="${1}"
1112 | 	shift
1113 | 	# No further arguments expected
1114 | 	#
1115 | 	if [[ $# -gt 0 ]]; then
1116 | 		printf "my-alternatives: error: unrecognized option: %s.  see 'my-alternatives help select' for usage\n" "${1}" >&2
1117 | 		exit 2
1118 | 	fi
1119 | 	# need to import?
1120 | 	#
1121 | 	if ! alt_group_exists "${name}"; then
1122 | 		do_import "${name}" || return $?
1123 | 	fi
1124 | 	command update-alternatives \
1125 | 		--altdir "${alt_root}/alts" --admindir "${alt_root}/admin" \
1126 | 		"--config" "${name}"
1127 | }
1128 | 
1129 | ##
1130 | # help_alias
1131 | # Generates help text for the various command aliases
1132 | #
1133 | # $1 = command
1134 | # $2 = alias
1135 | #
1136 | function help_alias() {
1137 | 	# Need to escape $ and \
1138 | 	cat <<-USAGE
1139 | 		${2} is an alias for the '${1}' command.
1140 | 
1141 | 		see 'my-alternatives help ${1}' for usage.
1142 | 
1143 | 	USAGE
1144 | 	exit 2
1145 | }
1146 | 
1147 | ##
1148 | # help_passthrough
1149 | # Generates help text for the various pass-through commands
1150 | #
1151 | # $1 = update-alternatives command
1152 | # $2 = my-alternatives command (optional)
1153 | #
1154 | function help_passthrough() {
1155 | 	# Need to escape $ and \
1156 | 	cat <<-USAGE
1157 | 		usage: my-alternatives ${2:-${1}} [option ...]
1158 | 
1159 | 		  invokes update-alternatives --${1} pointing to the currently-configured alternatives.
1160 | 
1161 | 		  all options are passed through, unmodified.
1162 | 
1163 | 		this is equivilent to:
1164 | 
1165 | 		  # <ALT_ROOT>="\${MY_ALTS_TMP:-\${MY_ALTS_HOME}}"
1166 | 		  update-alternatives --altdir "<ALT_ROOT>/alts" --admindir "<ALT_ROOT>/admin" --${1} [option ...]
1167 | 
1168 | 		more info:
1169 | 
1170 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about the '--${1}' command.
1171 | 
1172 | 	USAGE
1173 | 	exit 2
1174 | }
1175 | 
1176 | function help_update_alternatives_help() {
1177 | 	cat <<-'USAGE'
1178 | 		usage: my-alternatives ua-help
1179 | 
1180 | 		convenience command for invoking:
1181 | 
1182 | 		  update-alternatives --help
1183 | 
1184 | 	USAGE
1185 | 	exit 2
1186 | }
1187 | 
1188 | function help_update_alternatives_version() {
1189 | 	cat <<-'USAGE'
1190 | 		usage: my-alternatives ua-version
1191 | 
1192 | 		convenience command for invoking:
1193 | 
1194 | 		  update-alternatives --version
1195 | 
1196 | 	USAGE
1197 | 	exit 2
1198 | }
1199 | 
1200 | function help_update_alternatives() {
1201 | 	cat <<-'USAGE'
1202 | 		usage: my-alternatives ua [option ...]
1203 | 
1204 | 		  invokes update-alternatives pointing to the currently-configured alternatives.
1205 | 
1206 | 		  all options are passed through, unmodified.
1207 | 
1208 | 		this is equivilent to:
1209 | 
1210 | 		  # <ALT_ROOT>="\${MY_ALTS_TMP:-\${MY_ALTS_HOME}}"
1211 | 		  update-alternatives --altdir "<ALT_ROOT>/alts" --admindir "<ALT_ROOT>/admin" [option ...]
1212 | 
1213 | 		more info:
1214 | 
1215 | 		  see 'my-alternatives --help' to learn more about configuring your own alternatives.
1216 | 
1217 | 		  see 'update-alternatives --help' or 'man update-alternatives' to learn more about alternatives.
1218 | 
1219 | 	USAGE
1220 | 	exit 2
1221 | }
1222 | 
1223 | function do_update_alternatives() {
1224 | 	# Ensure alt_home configured
1225 | 	#
1226 | 	if [ -z "${MY_ALTS_HOME:-}" ]; then
1227 | 		printf "my-alternatives: error: shell session not confgured. see 'my-alternatives --help' for usage\n" >&2
1228 | 		exit 2
1229 | 	fi
1230 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME}}"
1231 | 	# Invoke update-alternatives
1232 | 	#
1233 | 	command update-alternatives \
1234 | 		--altdir "${alt_root}/alts" \
1235 | 		--admindir "${alt_root}/admin" \
1236 | 		"$@"
1237 | }
1238 | 
1239 | ##
1240 | # alt_group_exists
1241 | # Checks if a named alt group exists in the configured alt root
1242 | # NOTE: Assumes knowledge of the configuration's "admin" directory
1243 | # $1 = name
1244 | #
1245 | # returns 0 if exist 1 otherwise
1246 | #
1247 | function alt_group_exists() {
1248 | 	local alt_root="${MY_ALTS_TMP:-${MY_ALTS_HOME:?}}"
1249 | 	if [ -f "${alt_root}/admin/${1}" ]; then
1250 | 		return 0
1251 | 	fi
1252 | 	return 1
1253 | }
1254 | 
1255 | ##
1256 | # is_dir_in_path
1257 | # Checks if the provided entry exists in the provided colon-separated list
1258 | #
1259 | # $1 = path ( or any colon-sepearated list )
1260 | # $2 = dir ( entry to look for )
1261 | #
1262 | # Returns 0 if found 1 otherwise
1263 | #
1264 | # exmaple:
1265 | #
1266 | #    is_dir_in_path "${PATH}" /usr/local/bin && echo YES || echo NO
1267 | #
1268 | function is_dir_in_path() {
1269 | 	# 0 = success
1270 | 	# Most likely to be in middle, least likely to match full path
1271 | 	#
1272 | 	[[ "$1" == *":$2:"* || "$1" == "$2:"* || "$1" == *":$2" || "$1" == "$2" ]] && return 0 || return 1
1273 | }
1274 | 
1275 | ##
1276 | # $1 = file (assumed to represent a file ie last element removed for path checks)
1277 | #
1278 | function get_my_alt_rel_path() {
1279 | 	local file path
1280 | 	if [ "${1}" == "" ]; then
1281 | 		printf ""
1282 | 		return
1283 | 	else
1284 | 		file="$(basename "$1")"
1285 | 		path="$(dirname "$1")"
1286 | 		if [ "${file}" == "" ] || [ "${path}" == "." ] || [ "${path}" == "/" ]; then
1287 | 			printf "%s" "$1"
1288 | 			return
1289 | 		fi
1290 | 	fi
1291 | 	# Check $PATH
1292 | 	#
1293 | 	if is_dir_in_path "${PATH}" "${path}"; then
1294 | 		printf "/bin/%s" "${file}"
1295 | 		return
1296 | 	fi
1297 | 	# Check manpath
1298 | 	#
1299 | 	if command -v manpath &>/dev/null; then
1300 | 		local _manpath
1301 | 		_manpath="$(command manpath 2>/dev/null)"
1302 | 		while [ "${path}" != "." ] && [ "${path}" != "/" ]; do
1303 | 			if is_dir_in_path "${_manpath}" "${path}"; then
1304 | 				printf "/man/%s" "${file}"
1305 | 				return
1306 | 			fi
1307 | 			file="$(command basename "${path}")/${file}"
1308 | 			path="$(command dirname "${path}")"
1309 | 		done
1310 | 	fi
1311 | 	# Unknown
1312 | 	#
1313 | 	printf "%s" "$1"
1314 | }
1315 | 
1316 | # ##############################################################################
1317 | # BEGIN alternatives_parse_admin_redhat.bash v1.0.0
1318 | # ##############################################################################
1319 | 
1320 | ##
1321 | # alt_parse_admin_redhat - Parses RedHat's update-alternatives admin files
1322 | #
1323 | # adapted from:
1324 | #
1325 | #    https://github.com/fedora-sysv/chkconfig/blob/master/alternatives.c#L264
1326 | #
1327 | # $1 = file to read from (can be process sub)
1328 | # $2 = debug|trace
1329 | #
1330 | # example:
1331 | #
1332 | #    alt_parse_admin_redhat <( cat /var/lib/alternatives/pager )
1333 | #
1334 | function alt_parse_admin_redhat() {
1335 | 	# Reset global vars
1336 | 	#
1337 | 	ALT_GROUP_LINK=
1338 | 	#ALT_GROUP_NAME=
1339 | 	ALT_GROUP_SLAVE_NAMES=()
1340 | 	ALT_GROUP_SLAVE_LINKS=()
1341 | 	ALT_GROUP_STATUS= # auto | manual
1342 | 	#ALT_GROUP_CURRENT_VALUE=
1343 | 	#ALT_GROUP_CURRENT_INDEX=
1344 | 	ALT_GROUP_BEST_VALUE=
1345 | 	ALT_GROUP_BEST_INDEX=
1346 | 	ALT_GROUP_VALUES=()
1347 | 	ALT_GROUP_PRIORITIES=()
1348 | 	ALT_GROUP_FAMILIES=()
1349 | 	ALT_GROUP_INIT_SCRIPTS=()
1350 | 	# TODO Consider moving to serialized arrays for slave values
1351 | 	#ALT_GROUP_VALUE_${v}_SLAVE_${s}_VALUE
1352 | 	unset _ALT_TMP_SLAVE_INDEX
1353 | 
1354 | 	_ALT_PARSE_ADMIN_STATE="STATUS"
1355 | 	local IFS line lineno=0 # 1 on first use
1356 | 	while IFS="" read -r line || [ -n "${line}" ]; do
1357 | 		((lineno += 1))
1358 | 		# Keeps looping on return code 3, otherwise returns on !0
1359 | 		#
1360 | 		local return_code
1361 | 		while :; do
1362 | 			if [ "${2:-}" == "trace" ]; then
1363 | 				printf "# line NO  : %s\n" "${lineno}"
1364 | 				printf "# line TEXT: '%s'\n" "${line}"
1365 | 				printf "# state    : %s\n" "${_ALT_PARSE_ADMIN_STATE}"
1366 | 				printf "#  ---------\n"
1367 | 			fi
1368 | 			_alt_parse_admin_state_"${_ALT_PARSE_ADMIN_STATE}" "${line}"
1369 | 			return_code=$?
1370 | 			[[ $return_code -eq 3 ]] || break
1371 | 		done
1372 | 		[[ $return_code -eq 0 ]] || return $return_code
1373 | 	done <"${1}"
1374 | 	# Final state should be one of "eof candidate" states
1375 | 	#
1376 | 	if [ ! "${_ALT_PARSE_ADMIN_STATE}" = "MAYBE_ALT_START" ] && [ ! "${_ALT_PARSE_ADMIN_STATE}" = "MAYBE_ALT_SLAVE_VALUE" ]; then
1377 | 		printf "unexpected parse state: %s\n" "${_ALT_PARSE_ADMIN_STATE}" >&2
1378 | 		return 2
1379 | 	fi
1380 | 	if [ "${2:-}" == "trace" ] || [ "${2:-}" == "debug" ]; then
1381 | 		#printf "ALT_GROUP_NAME         : %s\n" "${ALT_GROUP_NAME}"
1382 | 		printf "ALT_GROUP_LINK         : %s\n" "${ALT_GROUP_LINK}"
1383 | 		printf "ALT_GROUP_SLAVE_NAMES  : %s\n" "${ALT_GROUP_SLAVE_NAMES[*]}"
1384 | 		printf "ALT_GROUP_SLAVE_LINKS  : %s\n" "${ALT_GROUP_SLAVE_LINKS[*]}"
1385 | 		printf "ALT_GROUP_STATUS       : %s\n" "${ALT_GROUP_STATUS}"
1386 | 		#printf "ALT_GROUP_CURRENT_VALUE: %s\n" "${ALT_GROUP_CURRENT_VALUE}"
1387 | 		#printf "ALT_GROUP_CURRENT_INDEX: %s\n" "${ALT_GROUP_CURRENT_INDEX}"
1388 | 		printf "ALT_GROUP_BEST_VALUE   : %s\n" "${ALT_GROUP_BEST_VALUE}"
1389 | 		printf "ALT_GROUP_BEST_INDEX   : %s\n" "${ALT_GROUP_BEST_INDEX}"
1390 | 		printf "ALT_GROUP_VALUES       : %s\n" "${ALT_GROUP_VALUES[*]}"
1391 | 		printf "ALT_GROUP_PRIORITIES   : %s\n" "${ALT_GROUP_PRIORITIES[*]}"
1392 | 		printf "ALT_GROUP_FAMILIES     : %s\n" "${ALT_GROUP_FAMILIES[*]}"
1393 | 		printf "ALT_GROUP_INIT_SCRIPTS : %s\n" "${ALT_GROUP_INIT_SCRIPTS[*]}"
1394 | 		local v=0
1395 | 		while [[ $v -lt ${#ALT_GROUP_VALUES[@]} ]]; do
1396 | 			local s=0
1397 | 			while [[ $s -lt ${#ALT_GROUP_SLAVE_NAMES[@]} ]]; do
1398 | 				local alt_slave_value_ref="ALT_GROUP_VALUE_${v}_SLAVE_${s}_VALUE"
1399 | 				printf "${alt_slave_value_ref} : %s\n" "${!alt_slave_value_ref}"
1400 | 				((s += 1))
1401 | 			done
1402 | 			((v += 1))
1403 | 		done
1404 | 	fi
1405 | }
1406 | 
1407 | function _alt_parse_admin_state_STATUS() {
1408 | 	local regex='^((auto)|(manual))$'
1409 | 	if [[ "${1}" =~ $regex ]]; then
1410 | 		ALT_GROUP_STATUS="${BASH_REMATCH[1]}"
1411 | 		_ALT_PARSE_ADMIN_STATE="LINK"
1412 | 		return 0
1413 | 	else
1414 | 		printf "unable to parse Status field: %s\n" "${1}" >&2
1415 | 		return 2
1416 | 	fi
1417 | }
1418 | 
1419 | function _alt_parse_admin_state_LINK() {
1420 | 	local regex="^(/.+)$"
1421 | 	if [[ "${1}" =~ $regex ]]; then
1422 | 		ALT_GROUP_LINK="${BASH_REMATCH[1]}"
1423 | 		_ALT_PARSE_ADMIN_STATE="MAYBE_SLAVE_NAME"
1424 | 		return 0
1425 | 	else
1426 | 		printf "unable to parse Primary Link field: %s\n" "${1}" >&2
1427 | 		return 2
1428 | 	fi
1429 | }
1430 | 
1431 | function _alt_parse_admin_state_MAYBE_SLAVE_NAME() {
1432 | 	if [ -n "${1}" ]; then
1433 | 		_ALT_PARSE_ADMIN_STATE="SLAVE_NAME"
1434 | 		return 3 # re-check line
1435 | 	else
1436 | 		# blank line separates names/links from alternatives
1437 | 		# so consume the blank line, expect at least 1 alternative
1438 | 		#
1439 | 		_ALT_PARSE_ADMIN_STATE="ALT_VALUE"
1440 | 		return 0
1441 | 	fi
1442 | }
1443 | 
1444 | function _alt_parse_admin_state_SLAVE_NAME() {
1445 | 	local regex="^([^/].*)$"
1446 | 	if [[ "${1}" =~ $regex ]]; then
1447 | 		ALT_GROUP_SLAVE_NAMES+=("${BASH_REMATCH[1]}")
1448 | 		_ALT_PARSE_ADMIN_STATE="SLAVE_LINK"
1449 | 		return 0
1450 | 	else
1451 | 		printf "unable to parse Slave Name field: %s\n" "${1}" >&2
1452 | 		return 2
1453 | 	fi
1454 | }
1455 | 
1456 | function _alt_parse_admin_state_SLAVE_LINK() {
1457 | 	# Official source does not confirm leading / here
1458 | 	local regex="^(.+)$"
1459 | 	if [[ "${1}" =~ $regex ]]; then
1460 | 		ALT_GROUP_SLAVE_LINKS+=("${BASH_REMATCH[1]}")
1461 | 		_ALT_PARSE_ADMIN_STATE="MAYBE_SLAVE_NAME"
1462 | 		return 0
1463 | 	else
1464 | 		printf "unable to parse Slave Link field: %s\n" "${1}" >&2
1465 | 		return 2
1466 | 	fi
1467 | }
1468 | 
1469 | # eof candidate
1470 | function _alt_parse_admin_state_MAYBE_ALT_START() {
1471 | 	_ALT_PARSE_ADMIN_STATE="ALT_VALUE"
1472 | 	return 3 # re-check line
1473 | }
1474 | 
1475 | function _alt_parse_admin_state_ALT_VALUE() {
1476 | 	local regex="^(/.+)$"
1477 | 	if [[ "${1}" =~ $regex ]]; then
1478 | 		ALT_GROUP_VALUES+=("${BASH_REMATCH[1]}")
1479 | 		_ALT_PARSE_ADMIN_STATE="ALT_PRIORITY"
1480 | 		return 0
1481 | 	else
1482 | 		printf "unable to parse Alternative Value field: %s\n" "${1}" >&2
1483 | 		return 2
1484 | 	fi
1485 | }
1486 | 
1487 | function _alt_parse_admin_state_ALT_PRIORITY() {
1488 | 	# Official source accepts \s* but likely always receives \s+
1489 | 	local regex='^(@(.+)@)?([0-9]+)[[:space:]]*(.*)$'
1490 | 	if [[ "${1}" =~ $regex ]]; then
1491 | 		local alt_priority="${BASH_REMATCH[3]}"
1492 | 		local alt_index=${#ALT_GROUP_PRIORITIES[@]} # assign before += for 0-based value
1493 | 		ALT_GROUP_FAMILIES+=("${BASH_REMATCH[2]:-}")
1494 | 		ALT_GROUP_PRIORITIES+=("${alt_priority}")
1495 | 		ALT_GROUP_INIT_SCRIPTS+=("${BASH_REMATCH[4]:-}")
1496 | 		# We have to derive "BEST" manually, based in alternative priorities
1497 | 		#
1498 | 		if [ -z "${ALT_GROUP_BEST_INDEX}" ] || [[ "${ALT_GROUP_PRIORITIES[${ALT_GROUP_BEST_INDEX}]}" -lt "${alt_priority}" ]]; then
1499 | 			ALT_GROUP_BEST_INDEX="${alt_index}"
1500 | 			ALT_GROUP_BEST_VALUE="${ALT_GROUP_VALUES[${alt_index}]}"
1501 | 		fi
1502 | 		_ALT_PARSE_ADMIN_STATE="MAYBE_ALT_SLAVE_VALUE"
1503 | 		return 0
1504 | 	else
1505 | 		printf "unable to parse Alternative Priority field: %s\n" "${1}" >&2
1506 | 		return 2
1507 | 	fi
1508 | }
1509 | 
1510 | # eof candidate
1511 | function _alt_parse_admin_state_MAYBE_ALT_SLAVE_VALUE() {
1512 | 	: "${_ALT_TMP_SLAVE_INDEX:=0}" # Reset to 0 on first slave of each alternative
1513 | 	if [[ "${_ALT_TMP_SLAVE_INDEX}" -lt ${#ALT_GROUP_SLAVE_LINKS[@]} ]]; then
1514 | 		local regex="^(/.+)$"
1515 | 		if [[ "${1}" =~ $regex ]]; then
1516 | 			# Slave value order matches slave name order - no need to lookup
1517 | 			#
1518 | 			local slave_value="${BASH_REMATCH[1]}"
1519 | 			local alt_value_index=$((${#ALT_GROUP_VALUES[@]} - 1))
1520 | 			local slave_value_ref="ALT_GROUP_VALUE_${alt_value_index}_SLAVE_${_ALT_TMP_SLAVE_INDEX}_VALUE"
1521 | 			declare -g "${slave_value_ref}"="${slave_value}"
1522 | 			_ALT_TMP_SLAVE_INDEX=$((_ALT_TMP_SLAVE_INDEX + 1))
1523 | 			# Leave status unchanged
1524 | 			return 0
1525 | 		else
1526 | 			printf "unable to parse Alternative Slave Value field: %s\n" "${1}" >&2
1527 | 			return 2
1528 | 		fi
1529 | 	else
1530 | 		unset _ALT_TMP_SLAVE_INDEX
1531 | 		_ALT_PARSE_ADMIN_STATE="MAYBE_ALT_START"
1532 | 		return 3 # re-check line
1533 | 	fi
1534 | }
1535 | 
1536 | # ##############################################################################
1537 | # END alternatives_parse_admin_redhat.bash
1538 | # ##############################################################################
1539 | 
1540 | # Only process main logic if not being sourced (ie tested)
1541 | #
1542 | (return 0 2>/dev/null) || main "$@"
1543 | 


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