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 static inline void dup_devnull(int to)
  12 {
  13         int fd = open("/dev/null", O_RDWR);
  14         dup2(fd, to);
  15         close(fd);
  16 }
  17
  18 int start_command(struct child_process *cmd)
  19 {
  20         int need_in, need_out, need_err;
  21         int fdin[2], fdout[2], fderr[2];
  22
  23         need_in = !cmd->no_stdin && cmd->in < 0;
  24         if (need_in) {
  25                 if (pipe(fdin) < 0)
  26                         return -ERR_RUN_COMMAND_PIPE;
  27                 cmd->in = fdin[1];
  28                 cmd->close_in = 1;
  29         }
  30
  31         need_out = !cmd->no_stdout
  32                 && !cmd->stdout_to_stderr
  33                 && cmd->out < 0;
  34         if (need_out) {
  35                 if (pipe(fdout) < 0) {
  36                         if (need_in)
  37                                 close_pair(fdin);
  38                         return -ERR_RUN_COMMAND_PIPE;
  39                 }
  40                 cmd->out = fdout[0];
  41                 cmd->close_out = 1;
  42         }
  43
  44         need_err = !cmd->no_stderr && cmd->err < 0;
  45         if (need_err) {
  46                 if (pipe(fderr) < 0) {
  47                         if (need_in)
  48                                 close_pair(fdin);
  49                         if (need_out)
  50                                 close_pair(fdout);
  51                         return -ERR_RUN_COMMAND_PIPE;
  52                 }
  53                 cmd->err = fderr[0];
  54         }
  55
  56 #ifndef __MINGW32__
  57         cmd->pid = fork();
  58         if (!cmd->pid) {
  59                 if (cmd->no_stdin)
  60                         dup_devnull(0);
  61                 else if (need_in) {
  62                         dup2(fdin[0], 0);
  63                         close_pair(fdin);
  64                 } else if (cmd->in) {
  65                         dup2(cmd->in, 0);
  66                         close(cmd->in);
  67                 }
  68
  69                 if (cmd->no_stdout)
  70                         dup_devnull(1);
  71                 else if (cmd->stdout_to_stderr)
  72                         dup2(2, 1);
  73                 else if (need_out) {
  74                         dup2(fdout[1], 1);
  75                         close_pair(fdout);
  76                 } else if (cmd->out > 1) {
  77                         dup2(cmd->out, 1);
  78                         close(cmd->out);
  79                 }
  80
  81                 if (cmd->no_stderr)
  82                         dup_devnull(2);
  83                 else if (need_err) {
  84                         dup2(fderr[1], 2);
  85                         close_pair(fderr);
  86                 }
  87
  88                 if (cmd->dir && chdir(cmd->dir))
  89                         die("exec %s: cd to %s failed (%s)", cmd->argv[0],
  90                             cmd->dir, strerror(errno));
  91                 if (cmd->env) {
  92                         for (; *cmd->env; cmd->env++) {
  93                                 if (strchr(*cmd->env, '='))
  94                                         putenv((char*)*cmd->env);
  95                                 else
  96                                         unsetenv(*cmd->env);
  97                         }
  98                 }
  99                 if (cmd->git_cmd) {
 100                         execv_git_cmd(cmd->argv);
 101                 } else {
 102                         execvp(cmd->argv[0], (char *const*) cmd->argv);
 103                 }
 104                 die("exec %s failed.", cmd->argv[0]);
 105         }
 106 #else
 107         int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 108         const char *sargv0 = cmd->argv[0];
 109         char **env = environ;
 110         struct strbuf git_cmd;
 111
 112         if (cmd->no_stdin) {
 113                 s0 = dup(0);
 114                 dup_devnull(0);
 115         } else if (need_in) {
 116                 s0 = dup(0);
 117                 dup2(fdin[0], 0);
 118         } else if (cmd->in) {
 119                 s0 = dup(0);
 120                 dup2(cmd->in, 0);
 121         }
 122
 123         if (cmd->no_stdout) {
 124                 s1 = dup(1);
 125                 dup_devnull(1);
 126         } else if (cmd->stdout_to_stderr) {
 127                 s1 = dup(1);
 128                 dup2(2, 1);
 129         } else if (need_out) {
 130                 s1 = dup(1);
 131                 dup2(fdout[1], 1);
 132         } else if (cmd->out > 1) {
 133                 s1 = dup(1);
 134                 dup2(cmd->out, 1);
 135         }
 136
 137         if (cmd->no_stderr) {
 138                 s2 = dup(2);
 139                 dup_devnull(2);
 140         } else if (need_err) {
 141                 s2 = dup(2);
 142                 dup2(fderr[1], 2);
 143         }
 144
 145         if (cmd->dir)
 146                 die("chdir in start_command() not implemented");
 147         if (cmd->env) {
 148                 env = copy_environ();
 149                 for (; *cmd->env; cmd->env++)
 150                         env = env_setenv(env, *cmd->env);
 151         }
 152
 153         if (cmd->git_cmd) {
 154                 strbuf_init(&git_cmd, 0);
 155                 strbuf_addf(&git_cmd, "git-%s", cmd->argv[0]);
 156                 cmd->argv[0] = git_cmd.buf;
 157         }
 158
 159         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 160
 161         if (cmd->env)
 162                 free_environ(env);
 163         if (cmd->git_cmd)
 164                 strbuf_release(&git_cmd);
 165
 166         cmd->argv[0] = sargv0;
 167         if (s0 >= 0)
 168                 dup2(s0, 0), close(s0);
 169         if (s1 >= 0)
 170                 dup2(s1, 1), close(s1);
 171         if (s2 >= 0)
 172                 dup2(s2, 2), close(s2);
 173 #endif
 174
 175         if (cmd->pid < 0) {
 176                 if (need_in)
 177                         close_pair(fdin);
 178                 if (need_out)
 179                         close_pair(fdout);
 180                 if (need_err)
 181                         close_pair(fderr);
 182                 return -ERR_RUN_COMMAND_FORK;
 183         }
 184
 185         if (need_in)
 186                 close(fdin[0]);
 187         else if (cmd->in)
 188                 close(cmd->in);
 189
 190         if (need_out)
 191                 close(fdout[1]);
 192         else if (cmd->out > 1)
 193                 close(cmd->out);
 194
 195         if (need_err)
 196                 close(fderr[1]);
 197
 198         return 0;
 199 }
 200
 201 static int wait_or_whine(pid_t pid)
 202 {
 203         for (;;) {
 204                 int status, code;
 205                 pid_t waiting = waitpid(pid, &status, 0);
 206
 207                 if (waiting < 0) {
 208                         if (errno == EINTR)
 209                                 continue;
 210                         error("waitpid failed (%s)", strerror(errno));
 211                         return -ERR_RUN_COMMAND_WAITPID;
 212                 }
 213                 if (waiting != pid)
 214                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 215                 if (WIFSIGNALED(status))
 216                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 217
 218                 if (!WIFEXITED(status))
 219                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 220                 code = WEXITSTATUS(status);
 221                 if (code)
 222                         return -code;
 223                 return 0;
 224         }
 225 }
 226
 227 int finish_command(struct child_process *cmd)
 228 {
 229         if (cmd->close_in)
 230                 close(cmd->in);
 231         if (cmd->close_out)
 232                 close(cmd->out);
 233         return wait_or_whine(cmd->pid);
 234 }
 235
 236 int run_command(struct child_process *cmd)
 237 {
 238         int code = start_command(cmd);
 239         if (code)
 240                 return code;
 241         return finish_command(cmd);
 242 }
 243
 244 static void prepare_run_command_v_opt(struct child_process *cmd,
 245                                       const char **argv,
 246                                       int opt)
 247 {
 248         memset(cmd, 0, sizeof(*cmd));
 249         cmd->argv = argv;
 250         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 251         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 252         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 253 }
 254
 255 int run_command_v_opt(const char **argv, int opt)
 256 {
 257         struct child_process cmd;
 258         prepare_run_command_v_opt(&cmd, argv, opt);
 259         return run_command(&cmd);
 260 }
 261
 262 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 263 {
 264         struct child_process cmd;
 265         prepare_run_command_v_opt(&cmd, argv, opt);
 266         cmd.dir = dir;
 267         return run_command(&cmd);
 268 }
 269
 270 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 271 {
 272         struct child_process cmd;
 273         prepare_run_command_v_opt(&cmd, argv, opt);
 274         cmd.dir = dir;
 275         cmd.env = env;
 276         return run_command(&cmd);
 277 }
 278
 279 #ifdef __MINGW32__
 280 static __stdcall unsigned run_thread(void *data)
 281 {
 282         struct async *async = data;
 283         return async->proc(async->fd_for_proc, async->data);
 284 }
 285 #endif
 286
 287 int start_async(struct async *async)
 288 {
 289         int pipe_out[2];
 290
 291         if (pipe(pipe_out) < 0)
 292                 return error("cannot create pipe: %s", strerror(errno));
 293         async->out = pipe_out[0];
 294
 295 #ifndef __MINGW32__
 296         async->pid = fork();
 297         if (async->pid < 0) {
 298                 error("fork (async) failed: %s", strerror(errno));
 299                 close_pair(pipe_out);
 300                 return -1;
 301         }
 302         if (!async->pid) {
 303                 close(pipe_out[0]);
 304                 exit(!!async->proc(pipe_out[1], async->data));
 305         }
 306         close(pipe_out[1]);
 307 #else
 308         async->fd_for_proc = pipe_out[1];
 309         async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 310         if (!async->tid) {
 311                 error("cannot create thread: %s", strerror(errno));
 312                 close_pair(pipe_out);
 313                 return -1;
 314         }
 315 #endif
 316         return 0;
 317 }
 318
 319 int finish_async(struct async *async)
 320 {
 321 #ifndef __MINGW32__
 322         int ret = 0;
 323
 324         if (wait_or_whine(async->pid))
 325                 ret = error("waitpid (async) failed");
 326 #else
 327         DWORD ret = 0;
 328         if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 329                 ret = error("waiting for thread failed: %lu", GetLastError());
 330         else if (!GetExitCodeThread(async->tid, &ret))
 331                 ret = error("cannot get thread exit code: %lu", GetLastError());
 332         CloseHandle(async->tid);
 333 #endif
 334         return ret;
 335 }