run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4 #include "spawn-pipe.h"
   5
   6 extern char **environ;
   7 static inline void close_pair(int fd[2])
   8 {
   9         close(fd[0]);
  10         close(fd[1]);
  11 }
  12
  13 int start_command(struct child_process *cmd)
  14 {
  15         int need_in, need_out;
  16         int fdin[2] = { -1, -1 };
  17         int fdout[2] = { -1, -1 };
  18         char **env = environ;
  19
  20         need_in = !cmd->no_stdin && cmd->in < 0;
  21         if (need_in) {
  22                 if (pipe(fdin) < 0)
  23                         return -ERR_RUN_COMMAND_PIPE;
  24                 cmd->in = fdin[1];
  25                 cmd->close_in = 1;
  26         }
  27
  28         need_out = !cmd->no_stdout
  29                 && !cmd->stdout_to_stderr
  30                 && cmd->out < 0;
  31         if (need_out) {
  32                 if (pipe(fdout) < 0) {
  33                         if (need_in)
  34                                 close_pair(fdin);
  35                         return -ERR_RUN_COMMAND_PIPE;
  36                 }
  37                 cmd->out = fdout[0];
  38                 cmd->close_out = 1;
  39         }
  40
  41         {
  42                 if (cmd->no_stdin)
  43                         fdin[0] = open("/dev/null", O_RDWR);
  44                 else if (need_in) {
  45                         /* nothing */
  46                 } else if (cmd->in) {
  47                         fdin[0] = cmd->in;
  48                 }
  49
  50                 if (cmd->no_stdout)
  51                         fdout[1] = open("/dev/null", O_RDWR);
  52                 else if (cmd->stdout_to_stderr)
  53                         fdout[1] = dup(2);
  54                 else if (need_out) {
  55                         /* nothing */
  56                 } else if (cmd->out > 1) {
  57                         fdout[1] = cmd->out;
  58                 }
  59
  60                 if (cmd->dir)
  61                         die("chdir in start_command() not implemented");
  62                 if (cmd->dir && chdir(cmd->dir))
  63                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
  64                             cmd->dir, strerror(errno));
  65                 if (cmd->env) {
  66                         if (cmd->merge_env) {
  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                         else
  76                                 env = cmd->env;
  77                 }
  78                 if (cmd->git_cmd) {
  79                         cmd->pid = spawnve_git_cmd(cmd->argv, fdin, fdout, env);
  80                 } else {
  81                         cmd->pid = spawnvpe_pipe(cmd->cmd ? cmd->cmd : cmd->argv[0], cmd->argv, env, fdin, fdout);
  82                 }
  83         }
  84         if (cmd->pid < 0) {
  85                 if (need_in)
  86                         close_pair(fdin);
  87                 if (need_out)
  88                         close_pair(fdout);
  89                 return -ERR_RUN_COMMAND_FORK;
  90         }
  91
  92         return 0;
  93 }
  94
  95 int finish_command(struct child_process *cmd)
  96 {
  97         if (cmd->close_in)
  98                 close(cmd->in);
  99         if (cmd->close_out)
 100                 close(cmd->out);
 101
 102         for (;;) {
 103                 int status, code;
 104                 pid_t waiting = waitpid(cmd->pid, &status, 0);
 105
 106                 if (waiting < 0) {
 107                         if (errno == EINTR)
 108                                 continue;
 109                         error("waitpid failed (%s)", strerror(errno));
 110                         return -ERR_RUN_COMMAND_WAITPID;
 111                 }
 112                 if (waiting != cmd->pid)
 113                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 114                 if (WIFSIGNALED(status))
 115                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 116
 117                 if (!WIFEXITED(status))
 118                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 119                 code = WEXITSTATUS(status);
 120                 if (code)
 121                         return -code;
 122                 return 0;
 123         }
 124 }
 125
 126 int run_command(struct child_process *cmd)
 127 {
 128         int code = start_command(cmd);
 129         if (code)
 130                 return code;
 131         return finish_command(cmd);
 132 }
 133
 134 static void prepare_run_command_v_opt(struct child_process *cmd,
 135                                       const char **argv,
 136                                       int opt)
 137 {
 138         memset(cmd, 0, sizeof(*cmd));
 139         cmd->argv = argv;
 140         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 141         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 142         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 143         cmd->merge_env = opt & RUN_COMMAND_NO_MERGE_ENV ? 0 : 1;
 144 }
 145
 146 int run_command_v_opt(const char **argv, int opt)
 147 {
 148         struct child_process cmd;
 149         prepare_run_command_v_opt(&cmd, argv, opt);
 150         return run_command(&cmd);
 151 }
 152
 153 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 154 {
 155         struct child_process cmd;
 156         prepare_run_command_v_opt(&cmd, argv, opt);
 157         cmd.dir = dir;
 158         return run_command(&cmd);
 159 }
 160
 161 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 162 {
 163         struct child_process cmd;
 164         prepare_run_command_v_opt(&cmd, argv, opt);
 165         cmd.dir = dir;
 166         cmd.env = env;
 167         return run_command(&cmd);
 168 }