Andrew's git / gitweb.git / run-command.c
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run-command.con commit rev-parse --branches/--tags/--remotes=pattern (b09fe97)
   1#include "cache.h"
   2#include "run-command.h"
   3#include "exec_cmd.h"
   4
   5static inline void close_pair(int fd[2])
   6{
   7        close(fd[0]);
   8        close(fd[1]);
   9}
  10
  11#ifndef WIN32
  12static inline void dup_devnull(int to)
  13{
  14        int fd = open("/dev/null", O_RDWR);
  15        dup2(fd, to);
  16        close(fd);
  17}
  18#endif
  19
  20static const char **prepare_shell_cmd(const char **argv)
  21{
  22        int argc, nargc = 0;
  23        const char **nargv;
  24
  25        for (argc = 0; argv[argc]; argc++)
  26                ; /* just counting */
  27        /* +1 for NULL, +3 for "sh -c" plus extra $0 */
  28        nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
  29
  30        if (argc < 1)
  31                die("BUG: shell command is empty");
  32
  33        if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
  34                nargv[nargc++] = "sh";
  35                nargv[nargc++] = "-c";
  36
  37                if (argc < 2)
  38                        nargv[nargc++] = argv[0];
  39                else {
  40                        struct strbuf arg0 = STRBUF_INIT;
  41                        strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
  42                        nargv[nargc++] = strbuf_detach(&arg0, NULL);
  43                }
  44        }
  45
  46        for (argc = 0; argv[argc]; argc++)
  47                nargv[nargc++] = argv[argc];
  48        nargv[nargc] = NULL;
  49
  50        return nargv;
  51}
  52
  53#ifndef WIN32
  54static int execv_shell_cmd(const char **argv)
  55{
  56        const char **nargv = prepare_shell_cmd(argv);
  57        trace_argv_printf(nargv, "trace: exec:");
  58        execvp(nargv[0], (char **)nargv);
  59        free(nargv);
  60        return -1;
  61}
  62#endif
  63
  64int start_command(struct child_process *cmd)
  65{
  66        int need_in, need_out, need_err;
  67        int fdin[2], fdout[2], fderr[2];
  68        int failed_errno = failed_errno;
  69
  70        /*
  71         * In case of errors we must keep the promise to close FDs
  72         * that have been passed in via ->in and ->out.
  73         */
  74
  75        need_in = !cmd->no_stdin && cmd->in < 0;
  76        if (need_in) {
  77                if (pipe(fdin) < 0) {
  78                        failed_errno = errno;
  79                        if (cmd->out > 0)
  80                                close(cmd->out);
  81                        goto fail_pipe;
  82                }
  83                cmd->in = fdin[1];
  84        }
  85
  86        need_out = !cmd->no_stdout
  87                && !cmd->stdout_to_stderr
  88                && cmd->out < 0;
  89        if (need_out) {
  90                if (pipe(fdout) < 0) {
  91                        failed_errno = errno;
  92                        if (need_in)
  93                                close_pair(fdin);
  94                        else if (cmd->in)
  95                                close(cmd->in);
  96                        goto fail_pipe;
  97                }
  98                cmd->out = fdout[0];
  99        }
 100
 101        need_err = !cmd->no_stderr && cmd->err < 0;
 102        if (need_err) {
 103                if (pipe(fderr) < 0) {
 104                        failed_errno = errno;
 105                        if (need_in)
 106                                close_pair(fdin);
 107                        else if (cmd->in)
 108                                close(cmd->in);
 109                        if (need_out)
 110                                close_pair(fdout);
 111                        else if (cmd->out)
 112                                close(cmd->out);
 113fail_pipe:
 114                        error("cannot create pipe for %s: %s",
 115                                cmd->argv[0], strerror(failed_errno));
 116                        errno = failed_errno;
 117                        return -1;
 118                }
 119                cmd->err = fderr[0];
 120        }
 121
 122        trace_argv_printf(cmd->argv, "trace: run_command:");
 123
 124#ifndef WIN32
 125        fflush(NULL);
 126        cmd->pid = fork();
 127        if (!cmd->pid) {
 128                if (cmd->no_stdin)
 129                        dup_devnull(0);
 130                else if (need_in) {
 131                        dup2(fdin[0], 0);
 132                        close_pair(fdin);
 133                } else if (cmd->in) {
 134                        dup2(cmd->in, 0);
 135                        close(cmd->in);
 136                }
 137
 138                if (cmd->no_stderr)
 139                        dup_devnull(2);
 140                else if (need_err) {
 141                        dup2(fderr[1], 2);
 142                        close_pair(fderr);
 143                }
 144
 145                if (cmd->no_stdout)
 146                        dup_devnull(1);
 147                else if (cmd->stdout_to_stderr)
 148                        dup2(2, 1);
 149                else if (need_out) {
 150                        dup2(fdout[1], 1);
 151                        close_pair(fdout);
 152                } else if (cmd->out > 1) {
 153                        dup2(cmd->out, 1);
 154                        close(cmd->out);
 155                }
 156
 157                if (cmd->dir && chdir(cmd->dir))
 158                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 159                            cmd->dir);
 160                if (cmd->env) {
 161                        for (; *cmd->env; cmd->env++) {
 162                                if (strchr(*cmd->env, '='))
 163                                        putenv((char *)*cmd->env);
 164                                else
 165                                        unsetenv(*cmd->env);
 166                        }
 167                }
 168                if (cmd->preexec_cb)
 169                        cmd->preexec_cb();
 170                if (cmd->git_cmd) {
 171                        execv_git_cmd(cmd->argv);
 172                } else if (cmd->use_shell) {
 173                        execv_shell_cmd(cmd->argv);
 174                } else {
 175                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 176                }
 177                trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 178                                strerror(errno));
 179                exit(127);
 180        }
 181        if (cmd->pid < 0)
 182                error("cannot fork() for %s: %s", cmd->argv[0],
 183                        strerror(failed_errno = errno));
 184#else
 185{
 186        int fhin = 0, fhout = 1, fherr = 2;
 187        const char **sargv = cmd->argv;
 188        char **env = environ;
 189
 190        if (cmd->no_stdin)
 191                fhin = open("/dev/null", O_RDWR);
 192        else if (need_in)
 193                fhin = dup(fdin[0]);
 194        else if (cmd->in)
 195                fhin = dup(cmd->in);
 196
 197        if (cmd->no_stderr)
 198                fherr = open("/dev/null", O_RDWR);
 199        else if (need_err)
 200                fherr = dup(fderr[1]);
 201
 202        if (cmd->no_stdout)
 203                fhout = open("/dev/null", O_RDWR);
 204        else if (cmd->stdout_to_stderr)
 205                fhout = dup(fherr);
 206        else if (need_out)
 207                fhout = dup(fdout[1]);
 208        else if (cmd->out > 1)
 209                fhout = dup(cmd->out);
 210
 211        if (cmd->dir)
 212                die("chdir in start_command() not implemented");
 213        if (cmd->env)
 214                env = make_augmented_environ(cmd->env);
 215
 216        if (cmd->git_cmd) {
 217                cmd->argv = prepare_git_cmd(cmd->argv);
 218        } else if (cmd->use_shell) {
 219                cmd->argv = prepare_shell_cmd(cmd->argv);
 220        }
 221
 222        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
 223                                  fhin, fhout, fherr);
 224        failed_errno = errno;
 225        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 226                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 227
 228        if (cmd->env)
 229                free_environ(env);
 230        if (cmd->git_cmd)
 231                free(cmd->argv);
 232
 233        cmd->argv = sargv;
 234        if (fhin != 0)
 235                close(fhin);
 236        if (fhout != 1)
 237                close(fhout);
 238        if (fherr != 2)
 239                close(fherr);
 240}
 241#endif
 242
 243        if (cmd->pid < 0) {
 244                if (need_in)
 245                        close_pair(fdin);
 246                else if (cmd->in)
 247                        close(cmd->in);
 248                if (need_out)
 249                        close_pair(fdout);
 250                else if (cmd->out)
 251                        close(cmd->out);
 252                if (need_err)
 253                        close_pair(fderr);
 254                errno = failed_errno;
 255                return -1;
 256        }
 257
 258        if (need_in)
 259                close(fdin[0]);
 260        else if (cmd->in)
 261                close(cmd->in);
 262
 263        if (need_out)
 264                close(fdout[1]);
 265        else if (cmd->out)
 266                close(cmd->out);
 267
 268        if (need_err)
 269                close(fderr[1]);
 270
 271        return 0;
 272}
 273
 274static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 275{
 276        int status, code = -1;
 277        pid_t waiting;
 278        int failed_errno = 0;
 279
 280        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 281                ;       /* nothing */
 282
 283        if (waiting < 0) {
 284                failed_errno = errno;
 285                error("waitpid for %s failed: %s", argv0, strerror(errno));
 286        } else if (waiting != pid) {
 287                error("waitpid is confused (%s)", argv0);
 288        } else if (WIFSIGNALED(status)) {
 289                code = WTERMSIG(status);
 290                error("%s died of signal %d", argv0, code);
 291                /*
 292                 * This return value is chosen so that code & 0xff
 293                 * mimics the exit code that a POSIX shell would report for
 294                 * a program that died from this signal.
 295                 */
 296                code -= 128;
 297        } else if (WIFEXITED(status)) {
 298                code = WEXITSTATUS(status);
 299                /*
 300                 * Convert special exit code when execvp failed.
 301                 */
 302                if (code == 127) {
 303                        code = -1;
 304                        failed_errno = ENOENT;
 305                        if (!silent_exec_failure)
 306                                error("cannot run %s: %s", argv0,
 307                                        strerror(ENOENT));
 308                }
 309        } else {
 310                error("waitpid is confused (%s)", argv0);
 311        }
 312        errno = failed_errno;
 313        return code;
 314}
 315
 316int finish_command(struct child_process *cmd)
 317{
 318        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 319}
 320
 321int run_command(struct child_process *cmd)
 322{
 323        int code = start_command(cmd);
 324        if (code)
 325                return code;
 326        return finish_command(cmd);
 327}
 328
 329static void prepare_run_command_v_opt(struct child_process *cmd,
 330                                      const char **argv,
 331                                      int opt)
 332{
 333        memset(cmd, 0, sizeof(*cmd));
 334        cmd->argv = argv;
 335        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 336        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 337        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 338        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 339        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 340}
 341
 342int run_command_v_opt(const char **argv, int opt)
 343{
 344        struct child_process cmd;
 345        prepare_run_command_v_opt(&cmd, argv, opt);
 346        return run_command(&cmd);
 347}
 348
 349int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 350{
 351        struct child_process cmd;
 352        prepare_run_command_v_opt(&cmd, argv, opt);
 353        cmd.dir = dir;
 354        cmd.env = env;
 355        return run_command(&cmd);
 356}
 357
 358#ifdef WIN32
 359static unsigned __stdcall run_thread(void *data)
 360{
 361        struct async *async = data;
 362        return async->proc(async->fd_for_proc, async->data);
 363}
 364#endif
 365
 366int start_async(struct async *async)
 367{
 368        int pipe_out[2];
 369
 370        if (pipe(pipe_out) < 0)
 371                return error("cannot create pipe: %s", strerror(errno));
 372        async->out = pipe_out[0];
 373
 374#ifndef WIN32
 375        /* Flush stdio before fork() to avoid cloning buffers */
 376        fflush(NULL);
 377
 378        async->pid = fork();
 379        if (async->pid < 0) {
 380                error("fork (async) failed: %s", strerror(errno));
 381                close_pair(pipe_out);
 382                return -1;
 383        }
 384        if (!async->pid) {
 385                close(pipe_out[0]);
 386                exit(!!async->proc(pipe_out[1], async->data));
 387        }
 388        close(pipe_out[1]);
 389#else
 390        async->fd_for_proc = pipe_out[1];
 391        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 392        if (!async->tid) {
 393                error("cannot create thread: %s", strerror(errno));
 394                close_pair(pipe_out);
 395                return -1;
 396        }
 397#endif
 398        return 0;
 399}
 400
 401int finish_async(struct async *async)
 402{
 403#ifndef WIN32
 404        int ret = wait_or_whine(async->pid, "child process", 0);
 405#else
 406        DWORD ret = 0;
 407        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 408                ret = error("waiting for thread failed: %lu", GetLastError());
 409        else if (!GetExitCodeThread(async->tid, &ret))
 410                ret = error("cannot get thread exit code: %lu", GetLastError());
 411        CloseHandle(async->tid);
 412#endif
 413        return ret;
 414}
 415
 416int run_hook(const char *index_file, const char *name, ...)
 417{
 418        struct child_process hook;
 419        const char **argv = NULL, *env[2];
 420        char index[PATH_MAX];
 421        va_list args;
 422        int ret;
 423        size_t i = 0, alloc = 0;
 424
 425        if (access(git_path("hooks/%s", name), X_OK) < 0)
 426                return 0;
 427
 428        va_start(args, name);
 429        ALLOC_GROW(argv, i + 1, alloc);
 430        argv[i++] = git_path("hooks/%s", name);
 431        while (argv[i-1]) {
 432                ALLOC_GROW(argv, i + 1, alloc);
 433                argv[i++] = va_arg(args, const char *);
 434        }
 435        va_end(args);
 436
 437        memset(&hook, 0, sizeof(hook));
 438        hook.argv = argv;
 439        hook.no_stdin = 1;
 440        hook.stdout_to_stderr = 1;
 441        if (index_file) {
 442                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 443                env[0] = index;
 444                env[1] = NULL;
 445                hook.env = env;
 446        }
 447
 448        ret = run_command(&hook);
 449        free(argv);
 450        return ret;
 451}