Created
July 14, 2010 04:52
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Wrapper program to make general applications into erlang ports.
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| /* | |
| * Wrapper program to make general applications into erlang ports. | |
| */ | |
| #include <stdio.h> | |
| #include <stdlib.h> | |
| #include <unistd.h> | |
| #include <signal.h> | |
| #include <sysexits.h> | |
| #include <sys/wait.h> | |
| #include <assert.h> | |
| static int caught = 0; | |
| static int grace = 0; | |
| static void caught_signal(int which) | |
| { | |
| caught = which; | |
| } | |
| static int wait_for_process(pid_t pid) | |
| { | |
| int rv = EX_SOFTWARE; | |
| int stats = 0; | |
| int i = 0; | |
| struct sigaction sig_handler; | |
| char buf[256]; | |
| sig_handler.sa_handler = caught_signal; | |
| sig_handler.sa_flags = 0; | |
| sigaction(SIGALRM, &sig_handler, NULL); | |
| sigaction(SIGHUP, &sig_handler, NULL); | |
| sigaction(SIGINT, &sig_handler, NULL); | |
| sigaction(SIGTERM, &sig_handler, NULL); | |
| sigaction(SIGPIPE, &sig_handler, NULL); | |
| sigaction(SIGCHLD, &sig_handler, NULL); | |
| fgets(buf, sizeof(buf), stdin); | |
| if (caught != SIGCHLD) { | |
| if (kill(pid, SIGTERM) < 0) { | |
| perror("Failed to kill my child."); | |
| exit(EX_SOFTWARE); | |
| } | |
| } | |
| /* Loop forever waiting for the process to quit */ | |
| for (i = 0; ;i++) { | |
| sleep(grace); | |
| pid_t p = waitpid(pid, &stats, WNOHANG); | |
| if (p == pid) { | |
| /* child exited. Let's get out of here */ | |
| rv = WIFEXITED(stats) ? | |
| WEXITSTATUS(stats) : | |
| (0x80 | WTERMSIG(stats)); | |
| break; | |
| } else { | |
| printf("Undead, sending sig N9NE\n"); | |
| if (kill(pid, SIGKILL) < 0) { | |
| /* Kill failed. Must have lost the process. :/ */ | |
| perror("lost child when trying to kill"); | |
| exit(EX_SOFTWARE); | |
| } | |
| } | |
| } | |
| return rv; | |
| } | |
| static int spawn_and_wait(int argc, char **argv) | |
| { | |
| int rv = EX_SOFTWARE; | |
| pid_t pid = fork(); | |
| assert(argc > 0); | |
| switch (pid) { | |
| case -1: | |
| perror("fork"); | |
| rv = EX_OSERR; | |
| break; /* NOTREACHED */ | |
| case 0: | |
| execvp(argv[0], argv); | |
| perror("exec"); | |
| rv = EX_SOFTWARE; | |
| break; /* NOTREACHED */ | |
| default: | |
| printf("%d\n", pid); | |
| fflush(stdout); | |
| rv = wait_for_process(pid); | |
| } | |
| return rv; | |
| } | |
| int main(int argc, char **argv) | |
| { | |
| assert(argc > 2); | |
| grace = atoi(argv[1]); | |
| return spawn_and_wait(argc-2, argv+2); | |
| } |
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