run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4 #include "spawn-pipe.h"
   5
   6 static inline void close_pair(int fd[2])
   7 {
   8         close(fd[0]);
   9         close(fd[1]);
  10 }
  11
  12 int start_command(struct child_process *cmd)
  13 {
  14         int need_in, need_out;
  15         int fdin[2] = { -1, -1 };
  16         int fdout[2] = { -1, -1 };
  17
  18         need_in = !cmd->no_stdin && cmd->in < 0;
  19         if (need_in) {
  20                 if (pipe(fdin) < 0)
  21                         return -ERR_RUN_COMMAND_PIPE;
  22                 cmd->in = fdin[1];
  23                 cmd->close_in = 1;
  24         }
  25
  26         need_out = !cmd->no_stdout
  27                 && !cmd->stdout_to_stderr
  28                 && cmd->out < 0;
  29         if (need_out) {
  30                 if (pipe(fdout) < 0) {
  31                         if (need_in)
  32                                 close_pair(fdin);
  33                         return -ERR_RUN_COMMAND_PIPE;
  34                 }
  35                 cmd->out = fdout[0];
  36                 cmd->close_out = 1;
  37         }
  38
  39         {
  40                 if (cmd->no_stdin)
  41                         fdin[0] = open("/dev/null", O_RDWR);
  42                 else if (need_in) {
  43                         /* nothing */
  44                 } else if (cmd->in) {
  45                         fdin[0] = cmd->in;
  46                 }
  47
  48                 if (cmd->no_stdout)
  49                         fdout[1] = open("/dev/null", O_RDWR);
  50                 else if (cmd->stdout_to_stderr)
  51                         fdout[1] = dup(2);
  52                 else if (need_out) {
  53                         /* nothing */
  54                 } else if (cmd->out > 1) {
  55                         fdout[1] = cmd->out;
  56                 }
  57
  58                 if (cmd->git_cmd) {
  59                         cmd->pid = spawnv_git_cmd(cmd->argv, fdin, fdout);
  60                 } else {
  61                         cmd->pid = spawnvpe_pipe(cmd->argv[0], cmd->argv, environ, fdin, fdout);
  62                 }
  63         }
  64         if (cmd->pid < 0) {
  65                 if (need_in)
  66                         close_pair(fdin);
  67                 if (need_out)
  68                         close_pair(fdout);
  69                 return -ERR_RUN_COMMAND_FORK;
  70         }
  71
  72         return 0;
  73 }
  74
  75 int finish_command(struct child_process *cmd)
  76 {
  77         if (cmd->close_in)
  78                 close(cmd->in);
  79         if (cmd->close_out)
  80                 close(cmd->out);
  81
  82         for (;;) {
  83                 int status, code;
  84                 pid_t waiting = waitpid(cmd->pid, &status, 0);
  85
  86                 if (waiting < 0) {
  87                         if (errno == EINTR)
  88                                 continue;
  89                         error("waitpid failed (%s)", strerror(errno));
  90                         return -ERR_RUN_COMMAND_WAITPID;
  91                 }
  92                 if (waiting != cmd->pid)
  93                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
  94                 if (WIFSIGNALED(status))
  95                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
  96
  97                 if (!WIFEXITED(status))
  98                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
  99                 code = WEXITSTATUS(status);
 100                 if (code)
 101                         return -code;
 102                 return 0;
 103         }
 104 }
 105
 106 int run_command(struct child_process *cmd)
 107 {
 108         int code = start_command(cmd);
 109         if (code)
 110                 return code;
 111         return finish_command(cmd);
 112 }
 113
 114 int run_command_v_opt(const char **argv, int opt)
 115 {
 116         struct child_process cmd;
 117         memset(&cmd, 0, sizeof(cmd));
 118         cmd.argv = argv;
 119         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 120         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 121         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 122         return run_command(&cmd);
 123 }