├── .gitignore ├── HISTORY ├── LICENSE ├── Makefile ├── README ├── retry.c ├── when.1 └── when.c /.gitignore: -------------------------------------------------------------------------------- 1 | when 2 | retry 3 | *.o 4 | .*~ 5 | .DS_Store 6 | -------------------------------------------------------------------------------- /HISTORY: -------------------------------------------------------------------------------- 1 | CHANGELOG 2 | * 2013 December 12 (v 0.2.1) 3 | 4 | - Attempt to exit with exit status of conditional 5 | - Merge in an option handling bug (thanks @sshaw!) 6 | 7 | * 2013 December 11 (v 0.2) 8 | 9 | - Support "zero" mode, which runs the conditional until it exits with a 10 | return value of 0. 11 | - Overhaul of pretty much everything, though cleanup still needs to occur. 12 | 13 | * 2013 December 10 (v 0.1) 14 | 15 | - Initial release. Supports "timebomb" mode only which runs the second 16 | command only if an alarm goes off before the first command terminates. 17 | - Allow a custom alarm time to be set. 18 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. {http://fsf.org/} 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | {one line to give the program's name and a brief idea of what it does.} 635 | Copyright (C) {year} {name of author} 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see {http://www.gnu.org/licenses/}. 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | moka-mode Copyright (C) 2013 Andrew Gwozdziewycz 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | {http://www.gnu.org/licenses/}. 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | {http://www.gnu.org/philosophy/why-not-lgpl.html}. 675 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | CFLAGS = -Wall -pedantic -Wno-parentheses 2 | PREFIX ?= /usr/local 3 | MANPATH ?= $(PREFIX)/share/man 4 | 5 | all: when retry 6 | 7 | when: when.c 8 | $(CC) $< $(CFLAGS) -o $@ 9 | 10 | retry: retry.c 11 | $(CC) $< $(CFLAGS) -o $@ 12 | 13 | README: when.1 14 | man -P cat ./when.1 | fmt -w 79 > $@ 15 | 16 | install: when retry 17 | install -m 0755 when $(PREFIX)/bin/when 18 | install -m 0644 when.1 $(MANPATH)/man1/when.1 19 | install -m 0755 retry $(PREFIX)/bin/retry 20 | 21 | uninstall: 22 | rm -f $(PREFIX)/bin/when 23 | rm -f $(MANPATH)/man1/when.1 24 | rm -f $(PREFIX)/bin/retry 25 | 26 | clean: 27 | rm -f when retry 28 | 29 | .PHONY: all clean install uninstall README 30 | -------------------------------------------------------------------------------- /README: -------------------------------------------------------------------------------- 1 | WHEN(1) 2 | 3 | NAME 4 | when - repeatedly runs a command, then another when the first succeeds 5 | 6 | SYNOPSIS 7 | when [-n ] [-t|-z] [-h] [-v] 8 | 9 | DESCRIPTION 10 | when runs conditional every N seconds awaiting for "success." Success 11 | is defined in one of two ways. In timebomb mode, -t, success is 12 | defined by whether or not the conditional is still running after N 13 | seconds (as specified by the -n flag). In zero mode, -z, success is 14 | achieved when conditional exits with a return value of 0. 15 | 16 | The -n flag allows the interval to be set (in seconds) between 17 | successive attempts at running the conditional 18 | 19 | when will run until interrupted, or command completes. 20 | 21 | 22 | OPTIONS 23 | -h Prints the help message and exits successfully. 24 | 25 | -n seconds 26 | Sets the interval for running the conditional to seconds 27 | In timebomb mode, the specified time in seconds will need to pass 28 | before the conditional succeeds. 29 | 30 | -t Sets the success mode to timebomb which succeeds after 31 | conditional has been running for at least seconds 32 | 33 | -v Prints the version and exits successfully. 34 | 35 | -V Turns on verbose output. Mostly useful for debugging purposes. 36 | 37 | -z Sets the success mode to zero which succeeds after conditional 38 | returns 0 the first time. The conditional is guaranteed to be run 39 | at most 1 time every seconds 40 | 41 | NOTE 42 | Note that both conditional and command are given to "sh -c" which 43 | means that you may need to use extra quoting to get the desired effect. 44 | 45 | Note that POSIX option processing is used (i.e., option processing 46 | stops at the first non-option argument). This means that flags 47 | after conditional don't get interpreted by when itself. 48 | 49 | EXIT STATUS 50 | when makes an effort to exit with the exit status returned by the 51 | conditional in timebomb mode. In zero mode the exit status should be, 52 | well, 0. 53 | 54 | EXAMPLES 55 | TODO more examples needed 56 | 57 | Suppose you have a failing build, xmessage will alert you when 58 | it succeeds. 59 | 60 | when "make" "xmessage 'hurrah, build passed'" 61 | 62 | Or you want to say hello to john when he logs on 63 | 64 | when "w | grep john" "echo 'hello, john' | write john" 65 | 66 | Or maybe you have a daemon failing in a tight loop due to 67 | misconfiguration or lack of resources. One can run it with when and 68 | be alerted to when it becomes happy 69 | 70 | when -n 10 -t "" "xmessage 'daemon running'" 71 | 72 | SEE ALSO 73 | watch(1) 74 | 75 | COPYRIGHT 76 | Copyright (C) 2013 Andrew Gwozdziewycz 77 | 78 | This program is free software: you can redistribute it and/or modify 79 | it under the terms of the GNU General Public License as published 80 | by the Free Software Foundation, either version 3 of the License, 81 | or (at your option) any later version. 82 | 83 | This program is distributed in the hope that it will be useful, 84 | but WITHOUT ANY WARRANTY; without even the implied warranty of 85 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 86 | General Public License for more details. 87 | 88 | You should have received a copy of the GNU General Public License 89 | along with this program. If not, see 90 | 91 | AUTHOR 92 | when was written by Andrew Gwozdziewycz in 2013 93 | 94 | 95 | 96 | 2013 97 | Dec 98 | 10 99 | WHEN(1) 100 | -------------------------------------------------------------------------------- /retry.c: -------------------------------------------------------------------------------- 1 | #include 2 | #include 3 | #include 4 | #include 5 | #include 6 | #include 7 | #include 8 | #include 9 | #include 10 | 11 | 12 | #define VERSION "0.2.1" 13 | 14 | typedef enum state { 15 | START = 1, 16 | CANCELLED, 17 | LAUNCHING, 18 | WAITING, 19 | RESTART, 20 | FINISHED 21 | } state_t; 22 | 23 | 24 | static state_t current_state = START; 25 | static int verbose = 0; 26 | static long alarm_time = 5; 27 | 28 | static char *exec_args[4] = { 29 | "/bin/sh", 30 | "-c", 31 | "", 32 | NULL 33 | }; 34 | 35 | 36 | static void 37 | msleep(long ms) 38 | { 39 | struct timespec tm; 40 | tm.tv_sec = ms / 1000; 41 | tm.tv_nsec = (ms % 1000) * 1000000; 42 | nanosleep(&tm, NULL); 43 | } 44 | 45 | 46 | static int 47 | run(char *command) 48 | { 49 | int now, last_time, chld_status; 50 | pid_t chld; 51 | 52 | if (verbose) { 53 | fprintf(stderr, "INFO: running at interval %ld until success\n", 54 | alarm_time); 55 | } 56 | 57 | exec_args[2] = strdup(command); 58 | 59 | do { 60 | switch (current_state) { 61 | case START: 62 | case RESTART: 63 | last_time = time(NULL); 64 | chld = fork(); 65 | if (chld < 0) { 66 | perror("fork"); 67 | _exit(EXIT_FAILURE); 68 | } 69 | else if (chld == 0) { 70 | if (verbose) { 71 | fprintf(stderr, "INFO: running %s in subshell\n", exec_args[2]); 72 | } 73 | 74 | if (execv(exec_args[0], exec_args) < 0) { 75 | perror("execv"); 76 | _exit(EXIT_FAILURE); 77 | } 78 | } 79 | else { 80 | current_state = WAITING; 81 | if (verbose) { 82 | fprintf(stderr, "INFO: switched to WAITING\n"); 83 | } 84 | rewait: 85 | if (waitpid(-1, &chld_status, 0) >= 0) { 86 | if (WEXITSTATUS(chld_status) == 0) { 87 | if (verbose) { 88 | fprintf(stderr, "INFO: FINISHED\n"); 89 | } 90 | 91 | current_state = FINISHED; 92 | } 93 | else { 94 | if (verbose) { 95 | fprintf(stderr, "INFO: non-zero exit status, " 96 | "WAITING for restart\n"); 97 | } 98 | current_state = WAITING; 99 | } 100 | } 101 | else { 102 | if (errno == EINTR) { 103 | goto rewait; 104 | } 105 | if (errno == ECHILD) { 106 | if (verbose) { 107 | fprintf(stderr, "INFO: FINISHED - 2\n"); 108 | } 109 | current_state = FINISHED; /* no more children */ 110 | } 111 | } 112 | } 113 | 114 | break; 115 | 116 | case WAITING: 117 | msleep(10); 118 | now = time(NULL); 119 | if ((now - last_time) >= alarm_time) { 120 | if (verbose) { 121 | fprintf(stderr, "INFO: finished WAITING, RESTARTING\n"); 122 | } 123 | 124 | current_state = RESTART; 125 | } 126 | 127 | break; 128 | 129 | default: 130 | break; 131 | } 132 | } 133 | while (current_state != FINISHED && 134 | current_state != CANCELLED); 135 | 136 | return 0; 137 | } 138 | 139 | 140 | static void 141 | usage(char *prog) 142 | { 143 | fprintf(stderr, "usage: %s [-n seconds] [-hvV] \n", prog); 144 | } 145 | 146 | 147 | int 148 | main(int argc, char **argv) 149 | { 150 | char ch; 151 | int i, ci, l; 152 | char command[1024]; 153 | char *current; 154 | 155 | if (argc > 1) { 156 | while ((ch = getopt(argc, argv, "+hn:vVx")) != -1) { 157 | switch (ch) { 158 | case 'h': 159 | usage(argv[0]); 160 | exit(EXIT_SUCCESS); 161 | break; 162 | case 'n': 163 | alarm_time = strtol(optarg, NULL, 10); 164 | if ((errno == ERANGE && 165 | (alarm_time == LONG_MAX || alarm_time == LONG_MIN)) 166 | || alarm_time <= 0) { 167 | fprintf(stderr, "ERROR: invalid seconds argument\n"); 168 | usage(argv[0]); 169 | exit(EXIT_FAILURE); 170 | } 171 | break; 172 | case 'v': 173 | printf("%s\n", VERSION); 174 | exit(EXIT_SUCCESS); 175 | break; 176 | case 'V': 177 | verbose = 1; 178 | break; 179 | default: 180 | usage(argv[0]); 181 | exit(EXIT_FAILURE); 182 | } 183 | } 184 | 185 | /* get command */ 186 | current = command; 187 | ci = 0; 188 | for (i = optind; i < argc; i++) { 189 | l = strlen(argv[i]); 190 | if ((ci + l + 1) < 1023) { 191 | if (i != optind) { 192 | current[ci++] = ' '; 193 | } 194 | strncpy(current + ci, argv[i], l); 195 | ci += l; 196 | } 197 | else { 198 | fprintf(stderr, "ERROR: command won't fit in buffer\n"); 199 | /* TODO: here is why dynamic allocation would be good */ 200 | exit(EXIT_FAILURE); 201 | } 202 | } 203 | current[ci] = '\0'; 204 | 205 | return run(command); 206 | } 207 | usage(argv[0]); 208 | return 0; 209 | } 210 | -------------------------------------------------------------------------------- /when.1: -------------------------------------------------------------------------------- 1 | .TH WHEN 1 "2013 Dec 10" " " "" 2 | .SH NAME 3 | when \- repeatedly runs a command, then another when the first succeeds 4 | .SH SYNOPSIS 5 | .B when 6 | .I [\-n ] [-t|-z] [-h] [-v] 7 | .SH DESCRIPTION 8 | .BR when 9 | runs 10 | .I conditional 11 | every 12 | .B N 13 | .I seconds 14 | awaiting for "success." Success is defined in one of two ways. In 15 | .I timebomb 16 | mode, 17 | .I \-t, 18 | success is defined by whether or not the 19 | .I conditional 20 | is still running after 21 | .B N 22 | .I seconds 23 | (as specified by the 24 | .I \-n 25 | flag). In 26 | .I zero 27 | mode, 28 | .I \-z, 29 | success is achieved when 30 | .I conditional 31 | exits with a return value of 0. 32 | .PP 33 | The 34 | .I -n 35 | flag allows the interval to be set (in seconds) between successive 36 | attempts at running the 37 | .I conditional 38 | . 39 | .PP 40 | .BR when 41 | will run until interrupted, or 42 | .I command 43 | completes. 44 | 45 | .SH OPTIONS 46 | .TP 47 | .B -h 48 | Prints the help message and exits successfully. 49 | .PP 50 | .TP 51 | .B -n \fIseconds\fP 52 | Sets the interval for running the 53 | .I conditional 54 | to 55 | .B seconds 56 | . This also means that in 57 | .I timebomb 58 | mode, 59 | .B seconds 60 | will need to pass before the conditional succeeds. 61 | .PP 62 | .TP 63 | .B -t 64 | Sets the success mode to 65 | .I timebomb 66 | which succeeds after 67 | .I conditional 68 | has been running for at least 69 | .I seconds 70 | . 71 | .PP 72 | .TP 73 | .B -v 74 | Prints the version and exits successfully. 75 | .PP 76 | .TP 77 | .B -V 78 | Turns on verbose output. Mostly useful for debugging purposes. 79 | .PP 80 | .TP 81 | .B -z 82 | Sets the success mode to 83 | .I zero 84 | which succeeds after 85 | .I conditional 86 | returns 0 the first time. The 87 | .I conditional 88 | is guaranteed to be run at most 1 time every 89 | .I seconds 90 | . 91 | .SH NOTE 92 | Note that both 93 | .I conditional 94 | and 95 | .I command 96 | are given to "sh -c" 97 | which means that you may need to use extra quoting to get the desired effect. 98 | .PP 99 | Note that POSIX option processing is used (i.e., option processing stops at 100 | the first non-option argument). This means that flags after 101 | .I conditional 102 | don't get interpreted by 103 | .BR when 104 | itself. 105 | .SH EXIT STATUS 106 | when makes an effort to exit with the exit status returned by the 107 | .I conditional 108 | in timebomb mode. In zero mode the exit status should be, well, 0. 109 | .SH EXAMPLES 110 | .PP 111 | .I TODO 112 | more examples needed 113 | .PP 114 | Suppose you have a failing build, xmessage will alert you when it succeeds. 115 | .IP 116 | when "make" "xmessage 'hurrah, build passed'" 117 | .PP 118 | Or you want to say hello to john when he logs on 119 | .IP 120 | when "w | grep john" "echo 'hello, john' | write john" 121 | .PP 122 | Or maybe you have a daemon failing in a tight loop due to misconfiguration or 123 | lack of resources. One can run it with when and be alerted to when it 124 | becomes happy 125 | .IP 126 | when -n 10 -t "" "xmessage 'daemon running'" 127 | .SH SEE ALSO 128 | watch(1) 129 | .SH COPYRIGHT 130 | Copyright (C) 2013 Andrew Gwozdziewycz 131 | .PP 132 | This program is free software: you can redistribute it and/or modify 133 | it under the terms of the GNU General Public License as published by 134 | the Free Software Foundation, either version 3 of the License, or 135 | (at your option) any later version. 136 | .PP 137 | This program is distributed in the hope that it will be useful, 138 | but WITHOUT ANY WARRANTY; without even the implied warranty of 139 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 140 | GNU General Public License for more details. 141 | .PP 142 | You should have received a copy of the GNU General Public License 143 | along with this program. If not, see 144 | .SH AUTHOR 145 | .B when 146 | was written by Andrew Gwozdziewycz in 2013 147 | -------------------------------------------------------------------------------- /when.c: -------------------------------------------------------------------------------- 1 | /** 2 | * This program is free software: you can redistribute it and/or modify 3 | * it under the terms of the GNU General Public License as published by 4 | * the Free Software Foundation, either version 3 of the License, or 5 | * (at your option) any later version. 6 | * 7 | * This program is distributed in the hope that it will be useful, 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 | * GNU General Public License for more details. 11 | * 12 | * You should have received a copy of the GNU General Public License 13 | * along with this program. If not, see 14 | */ 15 | 16 | #include 17 | #include 18 | #include 19 | #include 20 | #include 21 | #include 22 | #include 23 | #include 24 | #include 25 | #include 26 | #include 27 | 28 | #define VERSION "0.2.1" 29 | 30 | 31 | typedef enum state { 32 | START = 1, 33 | /* User has cancelled request */ 34 | CANCELLED, 35 | /* Launching conditional */ 36 | LAUNCHING, 37 | /* Waiting for alarm, or completion of conditional */ 38 | WAITING, 39 | /* Conditional died, and we got an alarm */ 40 | RESTART, 41 | /* Alarm before conditional died */ 42 | ALARM, 43 | /* We're ready to run finishing command */ 44 | FINISHED 45 | } state_t; 46 | 47 | static state_t current_state = START; 48 | static long alarm_time = 5; 49 | static int success_when_zero = 0; 50 | static int success_when_timebomb = 0; 51 | static int verbose = 0; 52 | static pid_t wait_for = 0; 53 | 54 | static char *execargs[4] = { 55 | "/bin/sh", 56 | "-c", 57 | "", 58 | NULL 59 | }; 60 | 61 | 62 | static void 63 | timebomb_handler(int signum) 64 | { 65 | switch (signum) { 66 | case SIGINT: 67 | current_state = CANCELLED; 68 | alarm(0); 69 | break; 70 | case SIGALRM: 71 | if (current_state != WAITING) { 72 | /* if we get an alarm before a SIGCHLD, we win */ 73 | current_state = ALARM; 74 | } 75 | else { 76 | /* The SIGCHLD set us into the WAITING state, but now we got an 77 | alarm, which puts us in the DIED state. Re-launch imminent */ 78 | current_state = RESTART; 79 | } 80 | break; 81 | } 82 | } 83 | 84 | static void 85 | zero_handler(int signum) 86 | { 87 | if (signum == SIGINT) { 88 | current_state = CANCELLED; 89 | } 90 | } 91 | 92 | /** 93 | * Used in timebomb mode 94 | */ 95 | static void 96 | chld_handler(int signum) 97 | { 98 | /* When we get a sigchld, we wait for the alarm before 99 | trying again, but put ourselves into a holding state */ 100 | if (signum == SIGCHLD) { 101 | current_state = WAITING; 102 | } 103 | } 104 | 105 | void 106 | setup_sigchld(void) 107 | { 108 | struct sigaction saction; 109 | sigemptyset(&saction.sa_mask); 110 | 111 | saction.sa_handler = chld_handler; 112 | saction.sa_flags = 0; 113 | 114 | if (sigaction(SIGCHLD, &saction, NULL)) { 115 | perror("sigaction"); 116 | _exit(EXIT_FAILURE); 117 | } 118 | } 119 | 120 | void 121 | setup_sighandlers(void) 122 | { 123 | struct sigaction saction; 124 | 125 | sigemptyset(&saction.sa_mask); 126 | saction.sa_flags = 0; 127 | 128 | if (success_when_zero) { 129 | saction.sa_handler = zero_handler; 130 | } 131 | else { 132 | saction.sa_handler = timebomb_handler; 133 | 134 | if (sigaction(SIGALRM, &saction, NULL)) { 135 | perror("sigaction"); 136 | _exit(EXIT_FAILURE); 137 | } 138 | } 139 | 140 | if (sigaction(SIGINT, &saction, NULL)) { 141 | perror("sigaction"); 142 | _exit(EXIT_FAILURE); 143 | } 144 | 145 | if (success_when_timebomb) { 146 | setup_sigchld(); 147 | } 148 | } 149 | 150 | static void 151 | msleep(long ms) 152 | { 153 | struct timespec tm; 154 | tm.tv_sec = ms / 1000; 155 | tm.tv_nsec = (ms % 1000) * 1000000; 156 | nanosleep(&tm, NULL); 157 | } 158 | 159 | static int 160 | finish() 161 | { 162 | sigset_t oset; 163 | pid_t finished_chld; 164 | int chld_status; 165 | 166 | if (current_state == ALARM || current_state == FINISHED) { 167 | finished_chld = fork(); 168 | if (finished_chld < 0) { 169 | perror("fork"); 170 | _exit(EXIT_FAILURE); 171 | } 172 | else if (finished_chld == 0) { 173 | if (execv(execargs[0], execargs) < 0) { 174 | perror("execv"); 175 | _exit(EXIT_FAILURE); 176 | } 177 | } 178 | else { 179 | /** 180 | * We have an interesting problem. In the timebomb mode, we want to 181 | * keep running until it completes. However, it may be 182 | * the case that finishes quickly, which will signal a 183 | * sigchld, and terminate the `when` process, and ultimately, the 184 | * that was originally running. 185 | * 186 | * The solution, for now (and this needs to be fixed), is to just 187 | * call waitpid() in the signal handler after we execute the finish 188 | * command. 189 | */ 190 | 191 | if (verbose) { 192 | fprintf(stderr, "INFO: ignoring sigchld for finish\n"); 193 | } 194 | 195 | if (sigprocmask(SIG_SETMASK, NULL, &oset) == 0) { 196 | sigaddset(&oset, SIGCHLD); 197 | sigprocmask(SIG_BLOCK, &oset, NULL); 198 | } 199 | 200 | do { 201 | if (waitpid(wait_for, &chld_status, 0) == -1) { 202 | perror("waitpid"); 203 | return EXIT_FAILURE; 204 | } 205 | } while (!WIFEXITED(chld_status) && !WIFSIGNALED(chld_status)); 206 | 207 | return WEXITSTATUS(chld_status); 208 | } 209 | } 210 | 211 | return 0; 212 | } 213 | 214 | static void 215 | run_zero() 216 | { 217 | int now; 218 | int last_time; 219 | int chld_status, status; 220 | 221 | if (verbose) { 222 | fprintf(stderr, "INFO: run in success when zero mode\n"); 223 | } 224 | 225 | do { 226 | switch (current_state) { 227 | case START: 228 | case RESTART: 229 | last_time = time(NULL); 230 | wait_for = fork(); 231 | if (wait_for < 0) { 232 | perror("fork"); 233 | _exit(EXIT_FAILURE); 234 | } 235 | else if (wait_for == 0) { 236 | if (verbose) { 237 | fprintf(stderr, "INFO: running %s\n", execargs[2]); 238 | } 239 | 240 | if (execv(execargs[0], execargs) < 0) { 241 | perror("execv"); 242 | _exit(EXIT_FAILURE); 243 | } 244 | } 245 | else { 246 | current_state = LAUNCHING; 247 | if (verbose) { 248 | fprintf(stderr, "INFO: waiting...\n"); 249 | } 250 | 251 | if (waitpid(wait_for, &chld_status, 0) >= 0) { 252 | status = WEXITSTATUS(chld_status); 253 | if (status == 0) { 254 | if (verbose) { 255 | fprintf(stderr, "INFO: FINISHED, will run finish command\n"); 256 | } 257 | 258 | current_state = FINISHED; 259 | } 260 | else { 261 | if (verbose) { 262 | fprintf(stderr, "INFO: > 0 exit code, WAITING for restart.\n"); 263 | } 264 | current_state = WAITING; 265 | } 266 | } 267 | else { 268 | fprintf(stderr, "INFO: failed waitpid, switching to WAITING\n"); 269 | current_state = WAITING; 270 | } 271 | } 272 | break; 273 | case WAITING: 274 | /* sleep, hoping that we get some progress */ 275 | msleep(10); 276 | now = time(NULL); 277 | if ((now - last_time) >= alarm_time) { 278 | /* process died, timeout occurred -- restart */ 279 | if (verbose) { 280 | fprintf(stderr, "INFO: ok to RESTART\n"); 281 | } 282 | current_state = RESTART; 283 | } 284 | break; 285 | default: 286 | break; 287 | } 288 | } 289 | while (current_state != FINISHED && 290 | current_state != CANCELLED); 291 | } 292 | 293 | 294 | static void 295 | run_timebomb() 296 | { 297 | 298 | if (verbose) { 299 | fprintf(stderr, "INFO: run in success when timebomb mode\n"); 300 | } 301 | 302 | do { 303 | switch (current_state) { 304 | case START: 305 | case RESTART: 306 | wait_for = fork(); 307 | if (wait_for < 0) { 308 | perror("fork"); 309 | _exit(EXIT_FAILURE); 310 | } 311 | else if (wait_for == 0) { /* launch conditional_cmd */ 312 | if (verbose) { 313 | fprintf(stderr, "INFO: running %s\n", execargs[0]); 314 | } 315 | 316 | if (execv(execargs[0], execargs) < 0) { 317 | perror("execv"); 318 | _exit(EXIT_FAILURE); 319 | } 320 | } 321 | else { 322 | if (verbose) { 323 | fprintf(stderr, "INFO: in LAUNCHING state, setting an alarm\n"); 324 | } 325 | current_state = LAUNCHING; 326 | alarm(alarm_time); 327 | } 328 | break; 329 | case LAUNCHING: 330 | case WAITING: 331 | /* sleep, hoping that we get some progress */ 332 | msleep(10); 333 | break; 334 | default: 335 | break; 336 | } 337 | } while (current_state != ALARM && 338 | current_state != CANCELLED && 339 | current_state != FINISHED); 340 | } 341 | 342 | void 343 | usage(int argc, char **argv) 344 | { 345 | fprintf(stderr, "usage: %s [-n seconds] " 346 | "[-h] [-t|-z] [-V] [-v] \n", 347 | argv[0]); 348 | } 349 | 350 | 351 | int 352 | main(int argc, char **argv) 353 | { 354 | char ch; 355 | 356 | if (argc > 1) { 357 | while ((ch = getopt(argc, argv, "hn:tvVz")) != -1) { 358 | switch (ch) { 359 | case 'h': 360 | usage(argc, argv); 361 | _exit(EXIT_SUCCESS); 362 | case 'n': 363 | alarm_time = strtol(optarg, NULL, 10); 364 | if ((errno == ERANGE && 365 | (alarm_time == LONG_MAX || alarm_time == LONG_MIN)) 366 | || (alarm_time <= 0)) { 367 | fprintf(stderr, "ERROR: invalid seconds argument\n"); 368 | usage(argc, argv); 369 | _exit(EXIT_FAILURE); 370 | } 371 | break; 372 | case 't': 373 | success_when_timebomb = 1; 374 | break; 375 | case 'v': 376 | printf("%s\n", VERSION); 377 | _exit(EXIT_SUCCESS); 378 | case 'V': 379 | verbose = 1; 380 | break; 381 | case 'z': 382 | success_when_zero = 1; 383 | break; 384 | default: 385 | usage(argc, argv); 386 | _exit(EXIT_FAILURE); 387 | } 388 | } 389 | 390 | if (success_when_timebomb && success_when_zero) { 391 | fprintf(stderr, "ERROR: can't use both timebomb and zero mode\n"); 392 | usage(argc, argv); 393 | return 1; 394 | } 395 | 396 | setup_sighandlers(); 397 | 398 | if ((argc - optind) == 2) { 399 | argv += optind; 400 | 401 | execargs[2] = strdup(argv[0]); 402 | if (success_when_timebomb) { 403 | run_timebomb(); 404 | } 405 | else { 406 | run_zero(); 407 | } 408 | 409 | if (current_state == FINISHED || current_state == ALARM) { 410 | execargs[2] = strdup(argv[1]); 411 | return finish(); 412 | } 413 | 414 | fprintf(stderr, "ERROR: something went wrong\n"); 415 | return 1; 416 | } 417 | } 418 | 419 | usage(argc, argv); 420 | return 0; 421 | } 422 | --------------------------------------------------------------------------------