run-command: add "use shell" option
[gitweb.git] / run-command.c
index ff3d8e2d8bf3208b7ad0f29d7cf76cc84a4ad0e6..b2bdcfda3df9cc9a50453dae33926da7377a7b57 100644 (file)
@@ -15,10 +15,53 @@ static inline void dup_devnull(int to)
        close(fd);
 }
 
+static const char **prepare_shell_cmd(const char **argv)
+{
+       int argc, nargc = 0;
+       const char **nargv;
+
+       for (argc = 0; argv[argc]; argc++)
+               ; /* just counting */
+       /* +1 for NULL, +3 for "sh -c" plus extra $0 */
+       nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
+
+       if (argc < 1)
+               die("BUG: shell command is empty");
+
+       nargv[nargc++] = "sh";
+       nargv[nargc++] = "-c";
+
+       if (argc < 2)
+               nargv[nargc++] = argv[0];
+       else {
+               struct strbuf arg0 = STRBUF_INIT;
+               strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
+               nargv[nargc++] = strbuf_detach(&arg0, NULL);
+       }
+
+       for (argc = 0; argv[argc]; argc++)
+               nargv[nargc++] = argv[argc];
+       nargv[nargc] = NULL;
+
+       return nargv;
+}
+
+#ifndef WIN32
+static int execv_shell_cmd(const char **argv)
+{
+       const char **nargv = prepare_shell_cmd(argv);
+       trace_argv_printf(nargv, "trace: exec:");
+       execvp(nargv[0], (char **)nargv);
+       free(nargv);
+       return -1;
+}
+#endif
+
 int start_command(struct child_process *cmd)
 {
        int need_in, need_out, need_err;
        int fdin[2], fdout[2], fderr[2];
+       int failed_errno = failed_errno;
 
        /*
         * In case of errors we must keep the promise to close FDs
@@ -28,9 +71,10 @@ int start_command(struct child_process *cmd)
        need_in = !cmd->no_stdin && cmd->in < 0;
        if (need_in) {
                if (pipe(fdin) < 0) {
+                       failed_errno = errno;
                        if (cmd->out > 0)
                                close(cmd->out);
-                       return -ERR_RUN_COMMAND_PIPE;
+                       goto fail_pipe;
                }
                cmd->in = fdin[1];
        }
@@ -40,11 +84,12 @@ int start_command(struct child_process *cmd)
                && cmd->out < 0;
        if (need_out) {
                if (pipe(fdout) < 0) {
+                       failed_errno = errno;
                        if (need_in)
                                close_pair(fdin);
                        else if (cmd->in)
                                close(cmd->in);
-                       return -ERR_RUN_COMMAND_PIPE;
+                       goto fail_pipe;
                }
                cmd->out = fdout[0];
        }
@@ -52,6 +97,7 @@ int start_command(struct child_process *cmd)
        need_err = !cmd->no_stderr && cmd->err < 0;
        if (need_err) {
                if (pipe(fderr) < 0) {
+                       failed_errno = errno;
                        if (need_in)
                                close_pair(fdin);
                        else if (cmd->in)
@@ -60,14 +106,18 @@ int start_command(struct child_process *cmd)
                                close_pair(fdout);
                        else if (cmd->out)
                                close(cmd->out);
-                       return -ERR_RUN_COMMAND_PIPE;
+fail_pipe:
+                       error("cannot create pipe for %s: %s",
+                               cmd->argv[0], strerror(failed_errno));
+                       errno = failed_errno;
+                       return -1;
                }
                cmd->err = fderr[0];
        }
 
        trace_argv_printf(cmd->argv, "trace: run_command:");
 
-#ifndef __MINGW32__
+#ifndef WIN32
        fflush(NULL);
        cmd->pid = fork();
        if (!cmd->pid) {
@@ -115,6 +165,8 @@ int start_command(struct child_process *cmd)
                        cmd->preexec_cb();
                if (cmd->git_cmd) {
                        execv_git_cmd(cmd->argv);
+               } else if (cmd->use_shell) {
+                       execv_shell_cmd(cmd->argv);
                } else {
                        execvp(cmd->argv[0], (char *const*) cmd->argv);
                }
@@ -122,7 +174,11 @@ int start_command(struct child_process *cmd)
                                strerror(errno));
                exit(127);
        }
+       if (cmd->pid < 0)
+               error("cannot fork() for %s: %s", cmd->argv[0],
+                       strerror(failed_errno = errno));
 #else
+{
        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
        const char **sargv = cmd->argv;
        char **env = environ;
@@ -162,17 +218,19 @@ int start_command(struct child_process *cmd)
 
        if (cmd->dir)
                die("chdir in start_command() not implemented");
-       if (cmd->env) {
-               env = copy_environ();
-               for (; *cmd->env; cmd->env++)
-                       env = env_setenv(env, *cmd->env);
-       }
+       if (cmd->env)
+               env = make_augmented_environ(cmd->env);
 
        if (cmd->git_cmd) {
                cmd->argv = prepare_git_cmd(cmd->argv);
+       } else if (cmd->use_shell) {
+               cmd->argv = prepare_shell_cmd(cmd->argv);
        }
 
        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
+       failed_errno = errno;
+       if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
+               error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 
        if (cmd->env)
                free_environ(env);
@@ -186,10 +244,10 @@ int start_command(struct child_process *cmd)
                dup2(s1, 1), close(s1);
        if (s2 >= 0)
                dup2(s2, 2), close(s2);
+}
 #endif
 
        if (cmd->pid < 0) {
-               int err = errno;
                if (need_in)
                        close_pair(fdin);
                else if (cmd->in)
@@ -200,9 +258,8 @@ int start_command(struct child_process *cmd)
                        close(cmd->out);
                if (need_err)
                        close_pair(fderr);
-               return err == ENOENT ?
-                       -ERR_RUN_COMMAND_EXEC :
-                       -ERR_RUN_COMMAND_FORK;
+               errno = failed_errno;
+               return -1;
        }
 
        if (need_in)
@@ -221,40 +278,51 @@ int start_command(struct child_process *cmd)
        return 0;
 }
 
-static int wait_or_whine(pid_t pid)
+static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 {
-       for (;;) {
-               int status, code;
-               pid_t waiting = waitpid(pid, &status, 0);
-
-               if (waiting < 0) {
-                       if (errno == EINTR)
-                               continue;
-                       error("waitpid failed (%s)", strerror(errno));
-                       return -ERR_RUN_COMMAND_WAITPID;
-               }
-               if (waiting != pid)
-                       return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
-               if (WIFSIGNALED(status))
-                       return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
-
-               if (!WIFEXITED(status))
-                       return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
+       int status, code = -1;
+       pid_t waiting;
+       int failed_errno = 0;
+
+       while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
+               ;       /* nothing */
+
+       if (waiting < 0) {
+               failed_errno = errno;
+               error("waitpid for %s failed: %s", argv0, strerror(errno));
+       } else if (waiting != pid) {
+               error("waitpid is confused (%s)", argv0);
+       } else if (WIFSIGNALED(status)) {
+               code = WTERMSIG(status);
+               error("%s died of signal %d", argv0, code);
+               /*
+                * This return value is chosen so that code & 0xff
+                * mimics the exit code that a POSIX shell would report for
+                * a program that died from this signal.
+                */
+               code -= 128;
+       } else if (WIFEXITED(status)) {
                code = WEXITSTATUS(status);
-               switch (code) {
-               case 127:
-                       return -ERR_RUN_COMMAND_EXEC;
-               case 0:
-                       return 0;
-               default:
-                       return -code;
+               /*
+                * Convert special exit code when execvp failed.
+                */
+               if (code == 127) {
+                       code = -1;
+                       failed_errno = ENOENT;
+                       if (!silent_exec_failure)
+                               error("cannot run %s: %s", argv0,
+                                       strerror(ENOENT));
                }
+       } else {
+               error("waitpid is confused (%s)", argv0);
        }
+       errno = failed_errno;
+       return code;
 }
 
 int finish_command(struct child_process *cmd)
 {
-       return wait_or_whine(cmd->pid);
+       return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 }
 
 int run_command(struct child_process *cmd)
@@ -274,6 +342,8 @@ static void prepare_run_command_v_opt(struct child_process *cmd,
        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
+       cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
+       cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 }
 
 int run_command_v_opt(const char **argv, int opt)
@@ -292,8 +362,8 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const
        return run_command(&cmd);
 }
 
-#ifdef __MINGW32__
-static __stdcall unsigned run_thread(void *data)
+#ifdef WIN32
+static unsigned __stdcall run_thread(void *data)
 {
        struct async *async = data;
        return async->proc(async->fd_for_proc, async->data);
@@ -308,7 +378,7 @@ int start_async(struct async *async)
                return error("cannot create pipe: %s", strerror(errno));
        async->out = pipe_out[0];
 
-#ifndef __MINGW32__
+#ifndef WIN32
        /* Flush stdio before fork() to avoid cloning buffers */
        fflush(NULL);
 
@@ -337,11 +407,8 @@ int start_async(struct async *async)
 
 int finish_async(struct async *async)
 {
-#ifndef __MINGW32__
-       int ret = 0;
-
-       if (wait_or_whine(async->pid))
-               ret = error("waitpid (async) failed");
+#ifndef WIN32
+       int ret = wait_or_whine(async->pid, "child process", 0);
 #else
        DWORD ret = 0;
        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
@@ -385,15 +452,7 @@ int run_hook(const char *index_file, const char *name, ...)
                hook.env = env;
        }
 
-       ret = start_command(&hook);
+       ret = run_command(&hook);
        free(argv);
-       if (ret) {
-               warning("Could not spawn %s", argv[0]);
-               return ret;
-       }
-       ret = finish_command(&hook);
-       if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
-               warning("%s exited due to uncaught signal", argv[0]);
-
        return ret;
 }