diff options
Diffstat (limited to 'lib/execute.c')
| -rw-r--r-- | lib/execute.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/lib/execute.c b/lib/execute.c new file mode 100644 index 0000000..554d3f0 --- /dev/null +++ b/lib/execute.c @@ -0,0 +1,278 @@ +/* Creation of autonomous subprocesses. + Copyright (C) 2001-2004, 2006-2013 Free Software Foundation, Inc. + Written by Bruno Haible <haible@clisp.cons.org>, 2001. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + + +#include <config.h> + +/* Specification. */ +#include "execute.h" + +#include <errno.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> + +#include "error.h" +#include "fatal-signal.h" +#include "wait-process.h" +#include "gettext.h" + +#define _(str) gettext (str) + +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ + +/* Native Windows API. */ +# include <process.h> +# include "w32spawn.h" + +#else + +/* Unix API. */ +# include <spawn.h> + +#endif + +/* The results of open() in this file are not used with fchdir, + therefore save some unnecessary work in fchdir.c. */ +#undef open +#undef close + + +#if defined EINTR && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) + +/* EINTR handling for close(), open(). + These functions can return -1/EINTR even though we don't have any + signal handlers set up, namely when we get interrupted via SIGSTOP. */ + +static int +nonintr_close (int fd) +{ + int retval; + + do + retval = close (fd); + while (retval < 0 && errno == EINTR); + + return retval; +} +#define close nonintr_close + +static int +nonintr_open (const char *pathname, int oflag, mode_t mode) +{ + int retval; + + do + retval = open (pathname, oflag, mode); + while (retval < 0 && errno == EINTR); + + return retval; +} +#undef open /* avoid warning on VMS */ +#define open nonintr_open + +#endif + + +/* Execute a command, optionally redirecting any of the three standard file + descriptors to /dev/null. Return its exit code. + If it didn't terminate correctly, exit if exit_on_error is true, otherwise + return 127. + If slave_process is true, the child process will be terminated when its + creator receives a catchable fatal signal. */ +int +execute (const char *progname, + const char *prog_path, char **prog_argv, + bool ignore_sigpipe, + bool null_stdin, bool null_stdout, bool null_stderr, + bool slave_process, bool exit_on_error, + int *termsigp) +{ +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ + + /* Native Windows API. */ + int orig_stdin; + int orig_stdout; + int orig_stderr; + int exitcode; + int nullinfd; + int nulloutfd; + + /* FIXME: Need to free memory allocated by prepare_spawn. */ + prog_argv = prepare_spawn (prog_argv); + + /* Save standard file handles of parent process. */ + if (null_stdin) + orig_stdin = dup_safer_noinherit (STDIN_FILENO); + if (null_stdout) + orig_stdout = dup_safer_noinherit (STDOUT_FILENO); + if (null_stderr) + orig_stderr = dup_safer_noinherit (STDERR_FILENO); + exitcode = -1; + + /* Create standard file handles of child process. */ + nullinfd = -1; + nulloutfd = -1; + if ((!null_stdin + || ((nullinfd = open ("NUL", O_RDONLY, 0)) >= 0 + && (nullinfd == STDIN_FILENO + || (dup2 (nullinfd, STDIN_FILENO) >= 0 + && close (nullinfd) >= 0)))) + && (!(null_stdout || null_stderr) + || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0 + && (!null_stdout + || nulloutfd == STDOUT_FILENO + || dup2 (nulloutfd, STDOUT_FILENO) >= 0) + && (!null_stderr + || nulloutfd == STDERR_FILENO + || dup2 (nulloutfd, STDERR_FILENO) >= 0) + && ((null_stdout && nulloutfd == STDOUT_FILENO) + || (null_stderr && nulloutfd == STDERR_FILENO) + || close (nulloutfd) >= 0)))) + /* Use spawnvpe and pass the environment explicitly. This is needed if + the program has modified the environment using putenv() or [un]setenv(). + On Windows, programs have two environments, one in the "environment + block" of the process and managed through SetEnvironmentVariable(), and + one inside the process, in the location retrieved by the 'environ' + macro. When using spawnvp() without 'e', the child process inherits a + copy of the environment block - ignoring the effects of putenv() and + [un]setenv(). */ + { + exitcode = spawnvpe (P_WAIT, prog_path, (const char **) prog_argv, + (const char **) environ); + if (exitcode < 0 && errno == ENOEXEC) + { + /* prog is not a native executable. Try to execute it as a + shell script. Note that prepare_spawn() has already prepended + a hidden element "sh.exe" to prog_argv. */ + --prog_argv; + exitcode = spawnvpe (P_WAIT, prog_argv[0], (const char **) prog_argv, + (const char **) environ); + } + } + if (nulloutfd >= 0) + close (nulloutfd); + if (nullinfd >= 0) + close (nullinfd); + + /* Restore standard file handles of parent process. */ + if (null_stderr) + undup_safer_noinherit (orig_stderr, STDERR_FILENO); + if (null_stdout) + undup_safer_noinherit (orig_stdout, STDOUT_FILENO); + if (null_stdin) + undup_safer_noinherit (orig_stdin, STDIN_FILENO); + + if (termsigp != NULL) + *termsigp = 0; + + if (exitcode == -1) + { + if (exit_on_error || !null_stderr) + error (exit_on_error ? EXIT_FAILURE : 0, errno, + _("%s subprocess failed"), progname); + return 127; + } + + return exitcode; + +#else + + /* Unix API. */ + /* Note about 127: Some errors during posix_spawnp() cause the function + posix_spawnp() to return an error code; some other errors cause the + subprocess to exit with return code 127. It is implementation + dependent which error is reported which way. We treat both cases as + equivalent. */ + sigset_t blocked_signals; + posix_spawn_file_actions_t actions; + bool actions_allocated; + posix_spawnattr_t attrs; + bool attrs_allocated; + int err; + pid_t child; + + if (slave_process) + { + sigprocmask (SIG_SETMASK, NULL, &blocked_signals); + block_fatal_signals (); + } + actions_allocated = false; + attrs_allocated = false; + if ((err = posix_spawn_file_actions_init (&actions)) != 0 + || (actions_allocated = true, + (null_stdin + && (err = posix_spawn_file_actions_addopen (&actions, + STDIN_FILENO, + "/dev/null", O_RDONLY, + 0)) + != 0) + || (null_stdout + && (err = posix_spawn_file_actions_addopen (&actions, + STDOUT_FILENO, + "/dev/null", O_RDWR, + 0)) + != 0) + || (null_stderr + && (err = posix_spawn_file_actions_addopen (&actions, + STDERR_FILENO, + "/dev/null", O_RDWR, + 0)) + != 0) + || (slave_process + && ((err = posix_spawnattr_init (&attrs)) != 0 + || (attrs_allocated = true, + (err = posix_spawnattr_setsigmask (&attrs, + &blocked_signals)) + != 0 + || (err = posix_spawnattr_setflags (&attrs, + POSIX_SPAWN_SETSIGMASK)) + != 0))) + || (err = posix_spawnp (&child, prog_path, &actions, + attrs_allocated ? &attrs : NULL, prog_argv, + environ)) + != 0)) + { + if (actions_allocated) + posix_spawn_file_actions_destroy (&actions); + if (attrs_allocated) + posix_spawnattr_destroy (&attrs); + if (slave_process) + unblock_fatal_signals (); + if (termsigp != NULL) + *termsigp = 0; + if (exit_on_error || !null_stderr) + error (exit_on_error ? EXIT_FAILURE : 0, err, + _("%s subprocess failed"), progname); + return 127; + } + posix_spawn_file_actions_destroy (&actions); + if (attrs_allocated) + posix_spawnattr_destroy (&attrs); + if (slave_process) + { + register_slave_subprocess (child); + unblock_fatal_signals (); + } + + return wait_subprocess (child, progname, ignore_sigpipe, null_stderr, + slave_process, exit_on_error, termsigp); + +#endif +} |