run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include <sys/wait.h>
   4
   5 static int run_external_command(int argc, const char **argv)
   6 {
   7         pid_t pid = fork();
   8
   9         if (pid < 0)
  10                 return -ERR_RUN_COMMAND_FORK;
  11         if (!pid) {
  12                 execvp(argv[0], (char *const*) argv);
  13                 return -ERR_RUN_COMMAND_EXEC;
  14         }
  15         for (;;) {
  16                 int status, code;
  17                 int retval = waitpid(pid, &status, 0);
  18
  19                 if (retval < 0) {
  20                         if (errno == EINTR)
  21                                 continue;
  22                         error("waitpid failed (%s)", strerror(retval));
  23                         return -ERR_RUN_COMMAND_WAITPID;
  24                 }
  25                 if (retval != pid)
  26                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
  27                 if (WIFSIGNALED(status))
  28                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
  29
  30                 if (!WIFEXITED(status))
  31                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
  32                 code = WEXITSTATUS(status);
  33                 if (code)
  34                         return -code;
  35                 return 0;
  36         }
  37 }
  38
  39 int run_command(const char *cmd, ...)
  40 {
  41         int argc;
  42         const char *argv[MAX_RUN_COMMAND_ARGS];
  43         const char *arg;
  44         va_list param;
  45
  46         fprintf(stderr, "run-command %s (%d)\n", cmd, ERR_RUN_COMMAND_EXEC);
  47
  48         va_start(param, cmd);
  49         argv[0] = cmd;
  50         argc = 1;
  51         while (argc < MAX_RUN_COMMAND_ARGS) {
  52                 arg = argv[argc++] = va_arg(param, char *);
  53                 if (!arg)
  54                         break;
  55         }
  56         va_end(param);
  57         if (MAX_RUN_COMMAND_ARGS <= argc)
  58                 return error("too many args to run %s", cmd);
  59         return run_external_command(argc, argv);
  60 }