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 need_out = !cmd->stdout_to_stderr && cmd->out < 0;
  15         int fdin[2], fdout[2];
  16
  17         if (need_in) {
  18                 if (pipe(fdin) < 0)
  19                         return -ERR_RUN_COMMAND_PIPE;
  20                 cmd->in = fdin[1];
  21                 cmd->close_in = 1;
  22         }
  23
  24         if (need_out) {
  25                 if (pipe(fdout) < 0) {
  26                         if (need_in)
  27                                 close_pair(fdin);
  28                         return -ERR_RUN_COMMAND_PIPE;
  29                 }
  30                 cmd->out = fdout[0];
  31                 cmd->close_out = 1;
  32         }
  33
  34         cmd->pid = fork();
  35         if (cmd->pid < 0) {
  36                 if (need_in)
  37                         close_pair(fdin);
  38                 if (need_out)
  39                         close_pair(fdout);
  40                 return -ERR_RUN_COMMAND_FORK;
  41         }
  42
  43         if (!cmd->pid) {
  44                 if (cmd->no_stdin) {
  45                         int fd = open("/dev/null", O_RDWR);
  46                         dup2(fd, 0);
  47                         close(fd);
  48                 } else if (need_in) {
  49                         dup2(fdin[0], 0);
  50                         close_pair(fdin);
  51                 } else if (cmd->in) {
  52                         dup2(cmd->in, 0);
  53                         close(cmd->in);
  54                 }
  55
  56                 if (cmd->stdout_to_stderr)
  57                         dup2(2, 1);
  58                 else if (need_out) {
  59                         dup2(fdout[1], 1);
  60                         close_pair(fdout);
  61                 } else if (cmd->out > 1) {
  62                         dup2(cmd->out, 1);
  63                         close(cmd->out);
  64                 }
  65
  66                 if (cmd->git_cmd) {
  67                         execv_git_cmd(cmd->argv);
  68                 } else {
  69                         execvp(cmd->argv[0], (char *const*) cmd->argv);
  70                 }
  71                 die("exec %s failed.", cmd->argv[0]);
  72         }
  73
  74         if (need_in)
  75                 close(fdin[0]);
  76         else if (cmd->in)
  77                 close(cmd->in);
  78
  79         if (need_out)
  80                 close(fdout[1]);
  81         else if (cmd->out > 1)
  82                 close(cmd->out);
  83
  84         return 0;
  85 }
  86
  87 int finish_command(struct child_process *cmd)
  88 {
  89         if (cmd->close_in)
  90                 close(cmd->in);
  91         if (cmd->close_out)
  92                 close(cmd->out);
  93
  94         for (;;) {
  95                 int status, code;
  96                 pid_t waiting = waitpid(cmd->pid, &status, 0);
  97
  98                 if (waiting < 0) {
  99                         if (errno == EINTR)
 100                                 continue;
 101                         error("waitpid failed (%s)", strerror(errno));
 102                         return -ERR_RUN_COMMAND_WAITPID;
 103                 }
 104                 if (waiting != cmd->pid)
 105                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 106                 if (WIFSIGNALED(status))
 107                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 108
 109                 if (!WIFEXITED(status))
 110                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 111                 code = WEXITSTATUS(status);
 112                 if (code)
 113                         return -code;
 114                 return 0;
 115         }
 116 }
 117
 118 int run_command(struct child_process *cmd)
 119 {
 120         int code = start_command(cmd);
 121         if (code)
 122                 return code;
 123         return finish_command(cmd);
 124 }
 125
 126 int run_command_v_opt(const char **argv, int opt)
 127 {
 128         struct child_process cmd;
 129         memset(&cmd, 0, sizeof(cmd));
 130         cmd.argv = argv;
 131         cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 132         cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 133         cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 134         return run_command(&cmd);
 135 }