├── LICENSE ├── Makefile ├── README ├── bin └── .gitignore └── src ├── concat.c ├── posh.c ├── posh.h ├── posh_clearenv.c ├── posh_dup.c ├── posh_main.c ├── posh_pipe.c ├── posh_read.c ├── posh_seq.c ├── posh_setenv.c ├── posh_sub.c ├── posh_unsetenv.c └── posh_write.c /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. By contrast, the GNU General Public 13 | License is intended to guarantee your freedom to share and change free 14 | software--to make sure the software is free for all its users. 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It is safest 289 | to attach them to the start of each source file to most effectively 290 | convey the exclusion of warranty; and each file should have at least 291 | the "copyright" line and a pointer to where the full notice is found. 292 | 293 | {description} 294 | Copyright (C) {year} {fullname} 295 | 296 | This program is free software; you can redistribute it and/or modify 297 | it under the terms of the GNU General Public License as published by 298 | the Free Software Foundation; either version 2 of the License, or 299 | (at your option) any later version. 300 | 301 | This program is distributed in the hope that it will be useful, 302 | but WITHOUT ANY WARRANTY; without even the implied warranty of 303 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 | GNU General Public License for more details. 305 | 306 | You should have received a copy of the GNU General Public License along 307 | with this program; if not, write to the Free Software Foundation, Inc., 308 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 | 310 | Also add information on how to contact you by electronic and paper mail. 311 | 312 | If the program is interactive, make it output a short notice like this 313 | when it starts in an interactive mode: 314 | 315 | Gnomovision version 69, Copyright (C) year name of author 316 | Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 | This is free software, and you are welcome to redistribute it 318 | under certain conditions; type `show c' for details. 319 | 320 | The hypothetical commands `show w' and `show c' should show the appropriate 321 | parts of the General Public License. Of course, the commands you use may 322 | be called something other than `show w' and `show c'; they could even be 323 | mouse-clicks or menu items--whatever suits your program. 324 | 325 | You should also get your employer (if you work as a programmer) or your 326 | school, if any, to sign a "copyright disclaimer" for the program, if 327 | necessary. Here is a sample; alter the names: 328 | 329 | Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 | `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 | 332 | {signature of Ty Coon}, 1 April 1989 333 | Ty Coon, President of Vice 334 | 335 | This General Public License does not permit incorporating your program into 336 | proprietary programs. If your program is a subroutine library, you may 337 | consider it more useful to permit linking proprietary applications with the 338 | library. If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. 340 | 341 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | SRCDIR=src 2 | BINDIR=bin 3 | 4 | all: posh-core utils 5 | 6 | posh-core: posh dup seq setenv unsetenv clearenv pipe read write sub 7 | 8 | posh: $(SRCDIR)/posh_main.c $(SRCDIR)/posh.c 9 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 10 | 11 | dup: $(SRCDIR)/posh_dup.c $(SRCDIR)/posh.c 12 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 13 | 14 | seq: $(SRCDIR)/posh_seq.c $(SRCDIR)/posh.c 15 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 16 | 17 | setenv: $(SRCDIR)/posh_setenv.c $(SRCDIR)/posh.c 18 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 19 | 20 | unsetenv: $(SRCDIR)/posh_unsetenv.c $(SRCDIR)/posh.c 21 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 22 | 23 | clearenv: $(SRCDIR)/posh_clearenv.c $(SRCDIR)/posh.c 24 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 25 | 26 | pipe: $(SRCDIR)/posh_pipe.c $(SRCDIR)/posh.c 27 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 28 | 29 | read: $(SRCDIR)/posh_read.c $(SRCDIR)/posh.c 30 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 31 | 32 | write: $(SRCDIR)/posh_write.c $(SRCDIR)/posh.c 33 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 34 | 35 | sub: $(SRCDIR)/posh_sub.c $(SRCDIR)/posh.c 36 | $(CC) $(CFLAGS) $< $(SRCDIR)/posh.c -o $(BINDIR)/$@ 37 | 38 | utils: concat 39 | 40 | concat: $(SRCDIR)/concat.c 41 | $(CC) $(CFLAGS) $< -o $(BINDIR)/$@ 42 | -------------------------------------------------------------------------------- /README: -------------------------------------------------------------------------------- 1 | posh is a modular shell. It uses separate processes to perform the different 2 | functions of the shell. 3 | 4 | The core of posh is the main shell program named 'posh'. This program simply 5 | reads command lines one after the other and prints a prompt. Commands are 6 | executed one after the other, until an empty command is encountered. 7 | 8 | A command is just a list of strings. posh has a special syntax for parsing lists 9 | of strings. It would be best to give an example: the input 10 | 11 | asdf jkl; (abc def) (foo (bar)) 12 | 13 | is parsed as the four strings: 14 | "asdf" 15 | "jkl;" 16 | "abc def" 17 | "foo (bar)" 18 | 19 | The point of the grouped parentheses is to escape the spaces passed as part 20 | of the command list of a sub-command. Let me explain that. Like bash, the first 21 | string in the command is used as the name of the program to execute. The 22 | following strings in the command are passed as arguments. Most posh processes 23 | expect one of their arguments to be an entire command. This enables each 24 | process to do something to its execution environment, like duplicate a file 25 | descriptor, then start up a child process by interpreting that command 26 | argument. 27 | 28 | Here is a list of the available processes: 29 | 30 | posh 31 | This is the main shell program. It expects no arguments. 32 | 33 | dup 34 | Usage: dup source dest command 35 | dup redirects I/O by calling dup2(), so that the file descriptor dest refers 36 | to the same file descriptor to which source refers. The following example prints 37 | "Hello, world!" on stderr: 38 | 39 | dup 2 1 (echo Hello, world!) 40 | 41 | 42 | read 43 | Usage: read file fd command 44 | read opens a file for reading on the given file descriptor. The common use is 45 | to open a file for reading on stdin. Example: 46 | 47 | read file 0 cat 48 | 49 | 50 | write 51 | Usage: write file fd command 52 | write opens (or creates) a file for writing on the given file descriptor. 53 | Example: 54 | 55 | write file 1 (echo Hello, world!) 56 | 57 | 58 | pipe 59 | Usage: pipe writePipe readPipe writeCommand readCommand 60 | pipe creates a pipe between two processes. One process gets the write end of 61 | the pipe, and the other process gets the read end. By assigning the read end to 62 | file descriptor 0 and the write end to file descriptor 1, we can mimic the behavior of pipes in bash. The following example prints "Hello, world!" on stderr: 63 | 64 | dup 2 1 (pipe 1 0 (echo Hello, world!) cat) 65 | 66 | 67 | setenv 68 | Usage: setenv variable value command 69 | setenv sets an environment variable in the child process. 70 | 71 | unsetenv 72 | Usage: unsetenv variable command 73 | unsetenv removes the value of an environment variable in the child process. 74 | 75 | 76 | clearenv 77 | Usage: clearenv command 78 | clearenv clears the entire environment for the child process. 79 | 80 | 81 | seq 82 | Usage: seq (commands) 83 | This process executes each of its arguments as a command, in order. Example: 84 | 85 | seq (echo Hello,) (echo world!) 86 | 87 | 88 | sub 89 | Think of sub as a minimal subshell. Its purpose is to allow for command 90 | substitution. The following example is equivalent to 'ls `pwd`' in bash: 91 | 92 | pipe 1 0 (seq (concat (ls )) pwd) sub 93 | 94 | sub simply runs one command line from stdin without printing any prompt. The 95 | concat program is provided for convenience. 96 | 97 | 98 | Compiling: 99 | To compile the posh suite, simply run make. You will want to put the posh/bin 100 | directory in your PATH, otherwise all posh programs have to be referred to 101 | by prefixing them with './'. 102 | -------------------------------------------------------------------------------- /bin/.gitignore: -------------------------------------------------------------------------------- 1 | * 2 | !.gitignore 3 | -------------------------------------------------------------------------------- /src/concat.c: -------------------------------------------------------------------------------- 1 | #include 2 | 3 | int main(int argc, char **argv) { 4 | int i; 5 | 6 | for (i = 1; i < argc; ++i) { 7 | printf("%s", argv[i]); 8 | } 9 | 10 | return 0; 11 | } 12 | -------------------------------------------------------------------------------- /src/posh.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | /* 7 | typedef struct POSHstring { 8 | char *base; 9 | size_t length; 10 | size_t allocated; 11 | } POSHstring; 12 | 13 | typedef struct POSHlistNode { 14 | POSHstring string; 15 | struct POSHlistNode *next; 16 | } POSHlistNode; 17 | 18 | typedef struct POSHlist { 19 | POSHlistNode *head; 20 | POSHlistNode *tail; 21 | } POSHlist; 22 | 23 | typedef struct POSHparser { 24 | POSHlist list; 25 | int parenthesesLevel; 26 | char last; 27 | char commentLine; 28 | } POSHparser; 29 | */ 30 | 31 | POSHlistNode POSHmakeListNode() { 32 | POSHlistNode node; 33 | 34 | node.string = POSHmakeString(); 35 | node.next = NULL; 36 | 37 | return node; 38 | } 39 | 40 | POSHlist POSHmakeList() { 41 | POSHlist list; 42 | 43 | list.head = NULL; 44 | list.tail = NULL; 45 | 46 | return list; 47 | } 48 | 49 | char **POSHlistToStringArray(POSHlist *list) { 50 | size_t arraySize = sizeof(char *); 51 | POSHlistNode *current = list->head; 52 | char **array; 53 | int index; 54 | 55 | while (current) { 56 | arraySize += sizeof(char *); 57 | current = current->next; 58 | } 59 | 60 | array = (char **) malloc(arraySize); 61 | 62 | current = list->head; 63 | index = 0; 64 | 65 | while (current) { 66 | array[index] = POSHgetStringValue(¤t->string); 67 | ++index; 68 | current = current->next; 69 | } 70 | 71 | array[index] = NULL; 72 | 73 | return array; 74 | } 75 | 76 | /* Assumes that all nodes were dynamically allocated */ 77 | /* Does not free the list itself */ 78 | void POSHfreeList(POSHlist *list) { 79 | POSHlistNode *temp; 80 | while (list->head) { 81 | temp = list->head; 82 | list->head = list->head->next; 83 | POSHfreeString(&temp->string); 84 | free(temp); 85 | } 86 | list->tail = NULL; 87 | } 88 | 89 | POSHparser POSHmakeParser() { 90 | POSHparser parser; 91 | 92 | parser.list = POSHmakeList(); 93 | parser.parenthesesLevel = 0; 94 | parser.last = 0; 95 | 96 | return parser; 97 | } 98 | 99 | void POSHfreeParser(POSHparser parser) { 100 | POSHfreeList(&parser.list); 101 | } 102 | 103 | /* TODO: This parser has some strange behavior. I'm meaning to rewrite it as 104 | * a recursive descent parser using a line buffer. In the meantime this 105 | * mostly works. */ 106 | void POSHsubmitCharacter(POSHparser *parser, char c) { 107 | POSHlistNode *newNode; 108 | 109 | if (c == '(') { 110 | if (parser->last == ' ' && parser->parenthesesLevel == 0) { 111 | /* Start a new string */ 112 | newNode = (POSHlistNode *) malloc(sizeof(POSHlistNode)); 113 | *newNode = POSHmakeListNode(); 114 | parser->list.tail->next = newNode; 115 | parser->list.tail = newNode; 116 | } 117 | 118 | if (parser->parenthesesLevel > 0) { 119 | POSHappendCharToString(&parser->list.tail->string, c); 120 | } 121 | 122 | ++parser->parenthesesLevel; 123 | } 124 | else if (parser->parenthesesLevel > 0 && c == ')') { 125 | --parser->parenthesesLevel; 126 | 127 | if (parser->parenthesesLevel > 0) { 128 | POSHappendCharToString(&parser->list.tail->string, c); 129 | } 130 | } 131 | else if (c != ' ' || parser->parenthesesLevel > 0) { 132 | if (!parser->list.head) { 133 | /* If the list is not yet initialized, initialize it. */ 134 | newNode = (POSHlistNode *) malloc(sizeof(POSHlistNode)); 135 | *newNode = POSHmakeListNode(); 136 | parser->list.head = parser->list.tail = newNode; 137 | } 138 | 139 | if (parser->last == ' ' && parser->parenthesesLevel == 0) { 140 | /* Start a new string */ 141 | newNode = (POSHlistNode *) malloc(sizeof(POSHlistNode)); 142 | *newNode = POSHmakeListNode(); 143 | parser->list.tail->next = newNode; 144 | parser->list.tail = newNode; 145 | } 146 | 147 | POSHappendCharToString(&parser->list.tail->string, c); 148 | } 149 | 150 | parser->last = c; 151 | } 152 | 153 | 154 | POSHstring POSHmakeString() { 155 | POSHstring string; 156 | 157 | string.base = (char *) malloc(POSH_ALLOC_SIZE); 158 | string.length = 0; 159 | string.allocated = POSH_ALLOC_SIZE; 160 | 161 | return string; 162 | } 163 | 164 | void POSHfreeString(POSHstring *string) { 165 | free(string->base); 166 | } 167 | 168 | void POSHappendToString(POSHstring *string, char *toAppend) { 169 | while (*toAppend) { 170 | POSHappendCharToString(string, *toAppend); 171 | ++toAppend; 172 | } 173 | } 174 | 175 | void POSHappendCharToString(POSHstring *string, char toAppend) { 176 | if (string->length + 2 > string->allocated) { 177 | string->base = 178 | (char *) realloc(string->base, string->allocated + POSH_ALLOC_SIZE); 179 | } 180 | 181 | string->base[string->length++] = toAppend; 182 | } 183 | 184 | /* Note: calling POSHappendToString or POSHappendCharToString after calling 185 | * POSHgetStringValue invalidates the string returned by POSHgetStringValue. */ 186 | char *POSHgetStringValue(POSHstring *string) { 187 | string->base[string->length] = 0; 188 | return string->base; 189 | } 190 | 191 | void POSHrunCommand(char *command) { 192 | POSHparser parser; 193 | char **array; 194 | char c; 195 | int pid, status; 196 | 197 | parser = POSHmakeParser(); 198 | 199 | while (c = *command++) { 200 | POSHsubmitCharacter(&parser, c); 201 | } 202 | 203 | array = POSHlistToStringArray(&parser.list); 204 | 205 | if (*array) { 206 | pid = fork(); 207 | if (pid) { 208 | wait(&status); 209 | } 210 | else { 211 | execvp(array[0], array); 212 | perror("execvp"); 213 | exit(1); 214 | } 215 | } 216 | 217 | free(array); 218 | POSHfreeParser(parser); 219 | } 220 | -------------------------------------------------------------------------------- /src/posh.h: -------------------------------------------------------------------------------- 1 | #ifndef POSH_HEADER 2 | #define POSH_HEADER 3 | 4 | #define YES 1 5 | #define NO 0 6 | 7 | #define POSH_ALLOC_SIZE 64 8 | 9 | typedef struct POSHstring { 10 | char *base; 11 | size_t length; 12 | size_t allocated; 13 | } POSHstring; 14 | 15 | typedef struct POSHlistNode { 16 | POSHstring string; 17 | struct POSHlistNode *next; 18 | } POSHlistNode; 19 | 20 | typedef struct POSHlist { 21 | POSHlistNode *head; 22 | POSHlistNode *tail; 23 | } POSHlist; 24 | 25 | typedef struct POSHparser { 26 | POSHlist list; 27 | int parenthesesLevel; 28 | char last; 29 | } POSHparser; 30 | 31 | 32 | POSHstring POSHmakeString(); 33 | void POSHappendToString(POSHstring *string, char *toAppend); 34 | void POSHappendCharToString(POSHstring *string, char toAppend); 35 | char *POSHgetStringValue(POSHstring *string); 36 | void POSHfreeString(POSHstring *string); 37 | 38 | POSHlist POSHmakeList(); 39 | char **POSHlistToStringArray(POSHlist *list); 40 | void POSHfreeList(POSHlist *list); 41 | 42 | POSHparser POSHmakeParser(); 43 | void POSHfreeParser(POSHparser); 44 | void POSHsubmitCharacter(POSHparser *parser, char c); 45 | 46 | void POSHrunCommand(char *command); 47 | 48 | #endif 49 | -------------------------------------------------------------------------------- /src/posh_clearenv.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | void clearEnv(char **envp); 7 | 8 | int main(int argc, char **argv, char **envp) { 9 | 10 | if (argc != 2) { 11 | fprintf(stderr, "Usage: clearenv command\n"); 12 | exit(1); 13 | } 14 | 15 | clearEnv(envp); 16 | 17 | POSHrunCommand(argv[1]); 18 | 19 | return 0; 20 | } 21 | 22 | void clearEnv(char **envp) { 23 | char **array; 24 | char *ptr; 25 | POSHlist list; 26 | POSHstring name; 27 | POSHlistNode *node; 28 | 29 | list = POSHmakeList(); 30 | 31 | while (*envp) { 32 | ptr = *envp; 33 | 34 | name = POSHmakeString(); 35 | while (*ptr && *ptr != '=') { 36 | POSHappendCharToString(&name, *ptr); 37 | ++ptr; 38 | } 39 | 40 | node = (POSHlistNode *) malloc(sizeof(POSHlistNode)); 41 | 42 | if (!node) { 43 | perror("malloc"); 44 | exit(1); 45 | } 46 | 47 | node->string = name; 48 | 49 | if (!list.tail) { 50 | list.tail = node; 51 | } 52 | 53 | node->next = list.head; 54 | list.head = node; 55 | 56 | ++envp; 57 | } 58 | 59 | node = list.head; 60 | while (node) { 61 | if (unsetenv(POSHgetStringValue(&node->string)) == -1) { 62 | perror("unsetenv"); 63 | } 64 | node = node->next; 65 | } 66 | 67 | POSHfreeList(&list); 68 | } 69 | -------------------------------------------------------------------------------- /src/posh_dup.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | 7 | int main(int argc, char **argv) { 8 | int sourceFD, destFD; 9 | 10 | if (argc != 4) { 11 | fprintf(stderr, "Usage: dup source dest command\n"); 12 | exit(1); 13 | } 14 | 15 | sourceFD = atoi(argv[1]); 16 | destFD = atoi(argv[2]); 17 | 18 | if (dup2(sourceFD, destFD) == -1) { 19 | perror("dup2"); 20 | exit(1); 21 | } 22 | 23 | POSHrunCommand(argv[3]); 24 | 25 | return 0; 26 | } 27 | -------------------------------------------------------------------------------- /src/posh_main.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | /* 7 | #define POSH_ALLOC_SIZE 64 8 | 9 | typedef struct POSHstring { 10 | char *base; 11 | size_t length; 12 | size_t allocated; 13 | } POSHstring; 14 | 15 | typedef struct POSHlistNode { 16 | POSHstring string; 17 | struct POSHlistNode *next; 18 | } POSHlistNode; 19 | 20 | typedef struct POSHlist { 21 | POSHlistNode *head; 22 | POSHlistNode *tail; 23 | } POSHlist; 24 | 25 | typedef struct POSHparser { 26 | POSHlist list; 27 | int parenthesesLevel; 28 | char last; 29 | char commentLine; 30 | } POSHparser; 31 | */ 32 | 33 | int main(int argc, char **argv) { 34 | POSHparser parser; 35 | char **array; 36 | char **iter; 37 | char c; 38 | char exit = NO; 39 | int pid; 40 | int status; 41 | 42 | while (!exit) { 43 | printf("> "); 44 | 45 | parser = POSHmakeParser(); 46 | 47 | while ((c = getchar()) != EOF && c != '\n') { 48 | POSHsubmitCharacter(&parser, c); 49 | } 50 | 51 | /* If the command line is empty, exit the shell. */ 52 | if (parser.list.head == NULL) { 53 | exit = YES; 54 | } 55 | else { 56 | array = POSHlistToStringArray(&parser.list); 57 | 58 | pid = fork(); 59 | if (pid) { 60 | wait(&status); 61 | } 62 | else { 63 | execvp(array[0], array); 64 | 65 | exit = YES; /* Exec failed, so exit the child */ 66 | } 67 | } 68 | 69 | POSHfreeParser(parser); 70 | } 71 | 72 | return 0; 73 | } 74 | -------------------------------------------------------------------------------- /src/posh_pipe.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | int main(int argc, char **argv) { 7 | POSHparser parser; 8 | char **array; 9 | char *ptr; 10 | char c; 11 | int pid; 12 | int status; 13 | int writePipe, readPipe; 14 | int pipes[2]; 15 | 16 | if (argc != 5) { 17 | fprintf(stderr, 18 | "Usage: pipe writePipe readPipe writeCommand readCommand\n"); 19 | exit(1); 20 | } 21 | 22 | writePipe = atoi(argv[1]); 23 | readPipe = atoi(argv[2]); 24 | 25 | if (pipe(pipes) == -1) { 26 | perror("pipe"); 27 | exit(1); 28 | } 29 | 30 | if (dup2(pipes[0], readPipe) == -1) { 31 | perror("dup2"); 32 | exit(1); 33 | } 34 | 35 | /* Parse the writing command */ 36 | 37 | parser = POSHmakeParser(); 38 | 39 | ptr = argv[3]; 40 | while (c = *ptr++) { 41 | POSHsubmitCharacter(&parser, c); 42 | } 43 | 44 | array = POSHlistToStringArray(&parser.list); 45 | 46 | /* Start the writing process */ 47 | if (*array) { 48 | pid = fork(); 49 | if (!pid) { 50 | if (dup2(pipes[1], writePipe) == -1) { 51 | perror("dup2"); 52 | exit(1); 53 | } 54 | 55 | execvp(array[0], array); 56 | perror("execvp"); 57 | exit(1); 58 | } 59 | } 60 | 61 | close(pipes[1]); 62 | free(array); 63 | POSHfreeParser(parser); 64 | 65 | /* Parse the reading command */ 66 | 67 | parser = POSHmakeParser(); 68 | 69 | ptr = argv[4]; 70 | while (c = *ptr++) { 71 | POSHsubmitCharacter(&parser, c); 72 | } 73 | 74 | array = POSHlistToStringArray(&parser.list); 75 | 76 | /* Start the reading process */ 77 | if (*array) { 78 | pid = fork(); 79 | if (!pid) { 80 | if (dup2(pipes[0], readPipe) == -1) { 81 | perror("dup2"); 82 | exit(1); 83 | } 84 | 85 | execvp(array[0], array); 86 | perror("execvp"); 87 | exit(1); 88 | } 89 | } 90 | 91 | close(pipes[0]); 92 | free(array); 93 | POSHfreeParser(parser); 94 | 95 | /* Wait for the two child processes */ 96 | wait(&status); 97 | wait(&status); 98 | 99 | return 0; 100 | } 101 | -------------------------------------------------------------------------------- /src/posh_read.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include 5 | #include "posh.h" 6 | 7 | 8 | int main(int argc, char **argv) { 9 | int openedFD, destFD; 10 | 11 | if (argc != 4) { 12 | fprintf(stderr, "Usage: read file fd command\n"); 13 | exit(1); 14 | } 15 | 16 | openedFD = open(argv[1], O_RDONLY); 17 | if (openedFD == -1) { 18 | perror("open"); 19 | exit(1); 20 | } 21 | 22 | destFD = atoi(argv[2]); 23 | 24 | if (dup2(openedFD, destFD) == -1) { 25 | perror("dup2"); 26 | exit(1); 27 | } 28 | 29 | POSHrunCommand(argv[3]); 30 | 31 | if (close(openedFD) == -1) { 32 | perror("close"); 33 | exit(1); 34 | } 35 | 36 | return 0; 37 | } 38 | -------------------------------------------------------------------------------- /src/posh_seq.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | 7 | int main(int argc, char **argv) { 8 | int i; 9 | 10 | if (argc == 1) { 11 | fprintf(stderr, "Usage: seq commands\n"); 12 | exit(1); 13 | } 14 | 15 | for (i = 1; i < argc; ++i) { 16 | POSHrunCommand(argv[i]); 17 | } 18 | 19 | return 0; 20 | } 21 | -------------------------------------------------------------------------------- /src/posh_setenv.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | 7 | int main(int argc, char **argv) { 8 | 9 | if (argc != 4) { 10 | fprintf(stderr, "Usage: setenv variable value command\n"); 11 | exit(1); 12 | } 13 | 14 | if (setenv(argv[1], argv[2], YES) == -1) { 15 | perror("setenv"); 16 | exit(1); 17 | } 18 | 19 | POSHrunCommand(argv[3]); 20 | 21 | return 0; 22 | } 23 | -------------------------------------------------------------------------------- /src/posh_sub.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | 7 | int main(int argc, char **argv) { 8 | POSHparser parser; 9 | char **array; 10 | char c; 11 | int pid; 12 | int status; 13 | 14 | if (argc != 1) { 15 | fprintf(stderr, "Usage: sub\n"); 16 | exit(1); 17 | } 18 | 19 | parser = POSHmakeParser(); 20 | 21 | while ((c = getchar()) != EOF && c != '\n') { 22 | POSHsubmitCharacter(&parser, c); 23 | } 24 | 25 | array = POSHlistToStringArray(&parser.list); 26 | 27 | pid = fork(); 28 | if (pid) { 29 | wait(&status); 30 | } 31 | else { 32 | execvp(array[0], array); 33 | perror("execvp"); 34 | exit(1); 35 | } 36 | 37 | POSHfreeParser(parser); 38 | 39 | return 0; 40 | } 41 | -------------------------------------------------------------------------------- /src/posh_unsetenv.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include "posh.h" 5 | 6 | 7 | int main(int argc, char **argv) { 8 | 9 | if (argc != 3) { 10 | fprintf(stderr, "Usage: unsetenv variable command\n"); 11 | exit(1); 12 | } 13 | 14 | if (unsetenv(argv[1]) == -1) { 15 | perror("unsetenv"); 16 | exit(1); 17 | } 18 | 19 | POSHrunCommand(argv[2]); 20 | 21 | return 0; 22 | } 23 | -------------------------------------------------------------------------------- /src/posh_write.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include 5 | #include 6 | #include "posh.h" 7 | 8 | 9 | int main(int argc, char **argv) { 10 | int openedFD, destFD; 11 | 12 | if (argc != 4) { 13 | fprintf(stderr, "Usage: write file fd command\n"); 14 | exit(1); 15 | } 16 | 17 | openedFD = open(argv[1], O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR); 18 | if (openedFD == -1) { 19 | perror("open"); 20 | exit(1); 21 | } 22 | 23 | destFD = atoi(argv[2]); 24 | 25 | if (dup2(openedFD, destFD) == -1) { 26 | perror("dup2"); 27 | exit(1); 28 | } 29 | 30 | POSHrunCommand(argv[3]); 31 | 32 | if (close(openedFD) == -1) { 33 | perror("close"); 34 | exit(1); 35 | } 36 | 37 | return 0; 38 | } 39 | --------------------------------------------------------------------------------