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                         if (strchr(*cmd->env, '='))
 151                                 die("setting environment in start_command() not implemented");
 152                         else
 153                                 env_unsetenv(env, *cmd->env);
 154                 }
 155         }
 156
 157         if (cmd->git_cmd) {
 158                 strbuf_init(&git_cmd, 0);
 159                 strbuf_addf(&git_cmd, "git-%s", cmd->argv[0]);
 160                 cmd->argv[0] = git_cmd.buf;
 161         }
 162
 163         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 164
 165         /* TODO: if (cmd->env) free env; */
 166
 167         if (cmd->git_cmd)
 168                 strbuf_release(&git_cmd);
 169
 170         cmd->argv[0] = sargv0;
 171         if (s0 >= 0)
 172                 dup2(s0, 0), close(s0);
 173         if (s1 >= 0)
 174                 dup2(s1, 1), close(s1);
 175         if (s2 >= 0)
 176                 dup2(s2, 2), close(s2);
 177 #endif
 178
 179         if (cmd->pid < 0) {
 180                 if (need_in)
 181                         close_pair(fdin);
 182                 if (need_out)
 183                         close_pair(fdout);
 184                 if (need_err)
 185                         close_pair(fderr);
 186                 return -ERR_RUN_COMMAND_FORK;
 187         }
 188
 189         if (need_in)
 190                 close(fdin[0]);
 191         else if (cmd->in)
 192                 close(cmd->in);
 193
 194         if (need_out)
 195                 close(fdout[1]);
 196         else if (cmd->out > 1)
 197                 close(cmd->out);
 198
 199         if (need_err)
 200                 close(fderr[1]);
 201
 202         return 0;
 203 }
 204
 205 static int wait_or_whine(pid_t pid)
 206 {
 207         for (;;) {
 208                 int status, code;
 209                 pid_t waiting = waitpid(pid, &status, 0);
 210
 211                 if (waiting < 0) {
 212                         if (errno == EINTR)
 213                                 continue;
 214                         error("waitpid failed (%s)", strerror(errno));
 215                         return -ERR_RUN_COMMAND_WAITPID;
 216                 }
 217                 if (waiting != pid)
 218                         return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 219                 if (WIFSIGNALED(status))
 220                         return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 221
 222                 if (!WIFEXITED(status))
 223                         return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 224                 code = WEXITSTATUS(status);
 225                 if (code)
 226                         return -code;
 227                 return 0;
 228         }
 229 }
 230
 231 int finish_command(struct child_process *cmd)
 232 {
 233         if (cmd->close_in)
 234                 close(cmd->in);
 235         if (cmd->close_out)
 236                 close(cmd->out);
 237         return wait_or_whine(cmd->pid);
 238 }
 239
 240 int run_command(struct child_process *cmd)
 241 {
 242         int code = start_command(cmd);
 243         if (code)
 244                 return code;
 245         return finish_command(cmd);
 246 }
 247
 248 static void prepare_run_command_v_opt(struct child_process *cmd,
 249                                       const char **argv,
 250                                       int opt)
 251 {
 252         memset(cmd, 0, sizeof(*cmd));
 253         cmd->argv = argv;
 254         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 255         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 256         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 257 }
 258
 259 int run_command_v_opt(const char **argv, int opt)
 260 {
 261         struct child_process cmd;
 262         prepare_run_command_v_opt(&cmd, argv, opt);
 263         return run_command(&cmd);
 264 }
 265
 266 int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 267 {
 268         struct child_process cmd;
 269         prepare_run_command_v_opt(&cmd, argv, opt);
 270         cmd.dir = dir;
 271         return run_command(&cmd);
 272 }
 273
 274 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 275 {
 276         struct child_process cmd;
 277         prepare_run_command_v_opt(&cmd, argv, opt);
 278         cmd.dir = dir;
 279         cmd.env = env;
 280         return run_command(&cmd);
 281 }
 282
 283 #ifdef __MINGW32__
 284 static __stdcall unsigned run_thread(void *data)
 285 {
 286         struct async *async = data;
 287         return async->proc(async->fd_for_proc, async->data);
 288 }
 289 #endif
 290
 291 int start_async(struct async *async)
 292 {
 293         int pipe_out[2];
 294
 295         if (pipe(pipe_out) < 0)
 296                 return error("cannot create pipe: %s", strerror(errno));
 297         async->out = pipe_out[0];
 298
 299 #ifndef __MINGW32__
 300         async->pid = fork();
 301         if (async->pid < 0) {
 302                 error("fork (async) failed: %s", strerror(errno));
 303                 close_pair(pipe_out);
 304                 return -1;
 305         }
 306         if (!async->pid) {
 307                 close(pipe_out[0]);
 308                 exit(!!async->proc(pipe_out[1], async->data));
 309         }
 310         close(pipe_out[1]);
 311 #else
 312         async->fd_for_proc = pipe_out[1];
 313         async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 314         if (!async->tid) {
 315                 error("cannot create thread: %s", strerror(errno));
 316                 close_pair(pipe_out);
 317                 return -1;
 318         }
 319 #endif
 320         return 0;
 321 }
 322
 323 int finish_async(struct async *async)
 324 {
 325 #ifndef __MINGW32__
 326         int ret = 0;
 327
 328         if (wait_or_whine(async->pid))
 329                 ret = error("waitpid (async) failed");
 330 #else
 331         DWORD ret = 0;
 332         if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 333                 ret = error("waiting for thread failed: %lu", GetLastError());
 334         else if (!GetExitCodeThread(async->tid, &ret))
 335                 ret = error("cannot get thread exit code: %lu", GetLastError());
 336         CloseHandle(async->tid);
 337 #endif
 338         return ret;
 339 }