git/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         char **env = environ;
  18
  19         need_in = !cmd->no_stdin && cmd->in < 0;
  20         if (need_in) {
  21                 if (pipe(fdin) < 0)
  22                         return -ERR_RUN_COMMAND_PIPE;
  23                 cmd->in = fdin[1];
  24                 cmd->close_in = 1;
  25         }
  26
  27         need_out = !cmd->no_stdout
  28                 && !cmd->stdout_to_stderr
  29                 && cmd->out < 0;
  30         if (need_out) {
  31                 if (pipe(fdout) < 0) {
  32                         if (need_in)
  33                                 close_pair(fdin);
  34                         return -ERR_RUN_COMMAND_PIPE;
  35                 }
  36                 cmd->out = fdout[0];
  37                 cmd->close_out = 1;
  38         }
  39
  40         {
  41                 if (cmd->no_stdin)
  42                         fdin[0] = open("/dev/null", O_RDWR);
  43                 else if (need_in) {
  44                         /* nothing */
  45                 } else if (cmd->in) {
  46                         fdin[0] = cmd->in;
  47                 }
  48
  49                 if (cmd->no_stdout)
  50                         fdout[1] = open("/dev/null", O_RDWR);
  51                 else if (cmd->stdout_to_stderr)
  52                         fdout[1] = dup(2);
  53                 else if (need_out) {
  54                         /* nothing */
  55                 } else if (cmd->out > 1) {
  56                         fdout[1] = cmd->out;
  57                 }
  58
  59                 if (cmd->dir)
  60                         die("chdir in start_command() not implemented");
  61                 if (cmd->dir && chdir(cmd->dir))
  62                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
  63                             cmd->dir, strerror(errno));
  64                 if (cmd->env) {
  65                         if (cmd->git_cmd)
  66                                 die("modifying environment for git_cmd in start_command() not implemented");
  67                         env = copy_environ();
  68                         for (; *cmd->env; cmd->env++) {
  69                                 if (strchr(*cmd->env, '='))
  70                                         die("setting environment in start_command() not implemented");
  71                                 else
  72                                         env_unsetenv(env, *cmd->env);
  73                         }
  74                 }
  75                 if (cmd->git_cmd) {
  76                         cmd->pid = spawnv_git_cmd(cmd->argv, fdin, fdout);
  77                 } else {
  78                         cmd->pid = spawnvpe_pipe(cmd->argv[0], cmd->argv, env, fdin, fdout);
  79                 }
  80         }
  81         if (cmd->pid < 0) {
  82                 if (need_in)
  83                         close_pair(fdin);
  84                 if (need_out)
  85                         close_pair(fdout);
  86                 return -ERR_RUN_COMMAND_FORK;
  87         }
  88
  89         return 0;
  90 }
  91
  92 int finish_command(struct child_process *cmd)
  93 {
  94         if (cmd->close_in)
  95                 close(cmd->in);
  96         if (cmd->close_out)
  97                 close(cmd->out);
  98
  99         for (;;) {
 100                 int status, code;
 101                 pid_t waiting = waitpid(cmd->pid, &status, 0);
 102
 103                 if (waiting < 0) {
 104                         if (errno == EINTR)
 105                                 continue;
 106                         error("waitpid failed (%s)", strerror(errno));
 107                         return -ERR_RUN_COMMAND_WAITPID;
 108                 }
 109                 if (waiting != cmd->pid)
 110                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 111                 if (WIFSIGNALED(status))
 112                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 113
 114                 if (!WIFEXITED(status))
 115                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 116                 code = WEXITSTATUS(status);
 117                 if (code)
 118                         return -code;
 119                 return 0;
 120         }
 121 }
 122
 123 int run_command(struct child_process *cmd)
 124 {
 125         int code = start_command(cmd);
 126         if (code)
 127                 return code;
 128         return finish_command(cmd);
 129 }
 130
 131 static void prepare_run_command_v_opt(struct child_process *cmd,
 132                                       const char **argv,
 133                                       int opt)
 134 {
 135         memset(cmd, 0, sizeof(*cmd));
 136         cmd->argv = argv;
 137         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 138         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 139         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 140 }
 141
 142 int run_command_v_opt(const char **argv, int opt)
 143 {
 144         struct child_process cmd;
 145         prepare_run_command_v_opt(&cmd, argv, opt);
 146         return run_command(&cmd);
 147 }
 148
 149 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 150 {
 151         struct child_process cmd;
 152         prepare_run_command_v_opt(&cmd, argv, opt);
 153         cmd.dir = dir;
 154         return run_command(&cmd);
 155 }
 156
 157 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 158 {
 159         struct child_process cmd;
 160         prepare_run_command_v_opt(&cmd, argv, opt);
 161         cmd.dir = dir;
 162         cmd.env = env;
 163         return run_command(&cmd);
 164 }