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, need_err;
  15         int fdin[2] = { -1, -1 };
  16         int fdout[2] = { -1, -1 };
  17         int fderr[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         need_err = !cmd->no_stderr && cmd->err < 0;
  42         if (need_err) {
  43                 if (pipe(fderr) < 0) {
  44                         if (need_in)
  45                                 close_pair(fdin);
  46                         if (need_out)
  47                                 close_pair(fdout);
  48                         return -ERR_RUN_COMMAND_PIPE;
  49                 }
  50                 cmd->err = fderr[0];
  51         }
  52
  53         {
  54                 if (cmd->no_stdin)
  55                         fdin[0] = open("/dev/null", O_RDWR);
  56                 else if (need_in) {
  57                         /* nothing */
  58                 } else if (cmd->in) {
  59                         fdin[0] = cmd->in;
  60                 }
  61
  62                 if (cmd->no_stdout)
  63                         fdout[1] = open("/dev/null", O_RDWR);
  64                 else if (cmd->stdout_to_stderr)
  65                         fdout[1] = dup(2);
  66                 else if (need_out) {
  67                         /* nothing */
  68                 } else if (cmd->out > 1) {
  69                         fdout[1] = cmd->out;
  70                 }
  71
  72                 if (cmd->no_stderr)
  73                         fderr[1] = open("/dev/null", O_RDWR);
  74                 else if (need_err) {
  75                         /* nothing */
  76                 }
  77
  78                 if (cmd->dir)
  79                         die("chdir in start_command() not implemented");
  80                 if (cmd->dir && chdir(cmd->dir))
  81                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
  82                             cmd->dir, strerror(errno));
  83                 if (cmd->env) {
  84                         if (cmd->git_cmd)
  85                                 die("modifying environment for git_cmd in start_command() not implemented");
  86                         env = copy_environ();
  87                         for (; *cmd->env; cmd->env++) {
  88                                 if (strchr(*cmd->env, '='))
  89                                         die("setting environment in start_command() not implemented");
  90                                 else
  91                                         env_unsetenv(env, *cmd->env);
  92                         }
  93                 }
  94                 if (cmd->git_cmd) {
  95                         cmd->pid = spawnv_git_cmd(cmd->argv, fdin, fdout);
  96                 } else {
  97                         cmd->pid = spawnvpe_pipe(cmd->argv[0], cmd->argv, env, fdin, fdout);
  98                 }
  99         }
 100         if (cmd->pid < 0) {
 101                 if (need_in)
 102                         close_pair(fdin);
 103                 if (need_out)
 104                         close_pair(fdout);
 105                 if (need_err)
 106                         close_pair(fderr);
 107                 return -ERR_RUN_COMMAND_FORK;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static int wait_or_whine(pid_t pid)
 114 {
 115         for (;;) {
 116                 int status, code;
 117                 pid_t waiting = waitpid(pid, &status, 0);
 118
 119                 if (waiting < 0) {
 120                         if (errno == EINTR)
 121                                 continue;
 122                         error("waitpid failed (%s)", strerror(errno));
 123                         return -ERR_RUN_COMMAND_WAITPID;
 124                 }
 125                 if (waiting != pid)
 126                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 127                 if (WIFSIGNALED(status))
 128                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 129
 130                 if (!WIFEXITED(status))
 131                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 132                 code = WEXITSTATUS(status);
 133                 if (code)
 134                         return -code;
 135                 return 0;
 136         }
 137 }
 138
 139 int finish_command(struct child_process *cmd)
 140 {
 141         if (cmd->close_in)
 142                 close(cmd->in);
 143         if (cmd->close_out)
 144                 close(cmd->out);
 145         return wait_or_whine(cmd->pid);
 146 }
 147
 148 int run_command(struct child_process *cmd)
 149 {
 150         int code = start_command(cmd);
 151         if (code)
 152                 return code;
 153         return finish_command(cmd);
 154 }
 155
 156 static void prepare_run_command_v_opt(struct child_process *cmd,
 157                                       const char **argv,
 158                                       int opt)
 159 {
 160         memset(cmd, 0, sizeof(*cmd));
 161         cmd->argv = argv;
 162         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 163         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 164         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 165 }
 166
 167 int run_command_v_opt(const char **argv, int opt)
 168 {
 169         struct child_process cmd;
 170         prepare_run_command_v_opt(&cmd, argv, opt);
 171         return run_command(&cmd);
 172 }
 173
 174 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 175 {
 176         struct child_process cmd;
 177         prepare_run_command_v_opt(&cmd, argv, opt);
 178         cmd.dir = dir;
 179         return run_command(&cmd);
 180 }
 181
 182 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 183 {
 184         struct child_process cmd;
 185         prepare_run_command_v_opt(&cmd, argv, opt);
 186         cmd.dir = dir;
 187         cmd.env = env;
 188         return run_command(&cmd);
 189 }
 190
 191 #ifdef __MINGW32__
 192 static __stdcall unsigned run_thread(void *data)
 193 {
 194         struct async *async = data;
 195         return async->proc(async->fd_for_proc, async->data);
 196 }
 197 #endif
 198
 199 int start_async(struct async *async)
 200 {
 201         int pipe_out[2];
 202
 203         if (pipe(pipe_out) < 0)
 204                 return error("cannot create pipe: %s", strerror(errno));
 205         async->out = pipe_out[0];
 206
 207 #ifndef __MINGW32__
 208         async->pid = fork();
 209         if (async->pid < 0) {
 210                 error("fork (async) failed: %s", strerror(errno));
 211                 close_pair(pipe_out);
 212                 return -1;
 213         }
 214         if (!async->pid) {
 215                 close(pipe_out[0]);
 216                 exit(!!async->proc(pipe_out[1], async->data));
 217         }
 218         close(pipe_out[1]);
 219 #else
 220         async->fd_for_proc = pipe_out[1];
 221         async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 222         if (!async->tid) {
 223                 error("cannot create thread: %s", strerror(errno));
 224                 close_pair(pipe_out);
 225                 return -1;
 226         }
 227 #endif
 228         return 0;
 229 }
 230
 231 int finish_async(struct async *async)
 232 {
 233 #ifndef __MINGW32__
 234         int ret = 0;
 235
 236         if (wait_or_whine(async->pid))
 237                 ret = error("waitpid (async) failed");
 238 #else
 239         DWORD ret = 0;
 240         if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 241                 ret = error("waiting for thread failed: %lu", GetLastError());
 242         else if (!GetExitCodeThread(async->tid, &ret))
 243                 ret = error("cannot get thread exit code: %lu", GetLastError());
 244         CloseHandle(async->tid);
 245 #endif
 246         return ret;
 247 }