run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4
   5 static inline void close_pair(int fd[2])
   6 {
   7         close(fd[0]);
   8         close(fd[1]);
   9 }
  10
  11 int start_command(struct child_process *cmd)
  12 {
  13         int need_in = !cmd->no_stdin && cmd->in < 0;
  14         int fdin[2];
  15
  16         if (need_in) {
  17                 if (pipe(fdin) < 0)
  18                         return -ERR_RUN_COMMAND_PIPE;
  19                 cmd->in = fdin[1];
  20                 cmd->close_in = 1;
  21         }
  22
  23         cmd->pid = fork();
  24         if (cmd->pid < 0) {
  25                 if (need_in)
  26                         close_pair(fdin);
  27                 return -ERR_RUN_COMMAND_FORK;
  28         }
  29
  30         if (!cmd->pid) {
  31                 if (cmd->no_stdin) {
  32                         int fd = open("/dev/null", O_RDWR);
  33                         dup2(fd, 0);
  34                         close(fd);
  35                 } else if (need_in) {
  36                         dup2(fdin[0], 0);
  37                         close_pair(fdin);
  38                 } else if (cmd->in) {
  39                         dup2(cmd->in, 0);
  40                         close(cmd->in);
  41                 }
  42
  43                 if (cmd->stdout_to_stderr)
  44                         dup2(2, 1);
  45                 if (cmd->git_cmd) {
  46                         execv_git_cmd(cmd->argv);
  47                 } else {
  48                         execvp(cmd->argv[0], (char *const*) cmd->argv);
  49                 }
  50                 die("exec %s failed.", cmd->argv[0]);
  51         }
  52
  53         if (need_in)
  54                 close(fdin[0]);
  55         else if (cmd->in)
  56                 close(cmd->in);
  57
  58         return 0;
  59 }
  60
  61 int finish_command(struct child_process *cmd)
  62 {
  63         if (cmd->close_in)
  64                 close(cmd->in);
  65
  66         for (;;) {
  67                 int status, code;
  68                 pid_t waiting = waitpid(cmd->pid, &status, 0);
  69
  70                 if (waiting < 0) {
  71                         if (errno == EINTR)
  72                                 continue;
  73                         error("waitpid failed (%s)", strerror(errno));
  74                         return -ERR_RUN_COMMAND_WAITPID;
  75                 }
  76                 if (waiting != cmd->pid)
  77                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
  78                 if (WIFSIGNALED(status))
  79                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
  80
  81                 if (!WIFEXITED(status))
  82                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
  83                 code = WEXITSTATUS(status);
  84                 if (code)
  85                         return -code;
  86                 return 0;
  87         }
  88 }
  89
  90 int run_command(struct child_process *cmd)
  91 {
  92         int code = start_command(cmd);
  93         if (code)
  94                 return code;
  95         return finish_command(cmd);
  96 }
  97
  98 int run_command_v_opt(const char **argv, int opt)
  99 {
 100         struct child_process cmd;
 101         memset(&cmd, 0, sizeof(cmd));
 102         cmd.argv = argv;
 103         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 104         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 105         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 106         return run_command(&cmd);
 107 }