Something went wrong. Try again.
🎥 Command line media player
Something went wrong. Try again.
C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161/* * This file is part of mpv. * * mpv is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * mpv 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with mpv. If not, see <http://www.gnu.org/licenses/>. */
#include "osdep/posix-spawn.h"#include <poll.h>#include <unistd.h>#include <sys/types.h>#include <sys/wait.h>#include <fcntl.h>#include <errno.h>#include <signal.h>
#include "osdep/subprocess.h"
#include "common/common.h"#include "misc/thread_tools.h"#include "osdep/io.h"#include "stream/stream.h"
extern char **environ;
#define SAFE_CLOSE(fd) do { if ((fd) >= 0) close((fd)); (fd) = -1; } while (0)
// A silly helper: automatically skips entries with negative FDsstatic int sparse_poll(struct pollfd *fds, int num_fds, int timeout){ struct pollfd p_fds[10]; int map[10]; if (num_fds > MP_ARRAY_SIZE(p_fds)) return -1; int p_num_fds = 0; for (int n = 0; n < num_fds; n++) { map[n] = -1; if (fds[n].fd < 0) continue; map[n] = p_num_fds; p_fds[p_num_fds++] = fds[n]; } int r = poll(p_fds, p_num_fds, timeout); for (int n = 0; n < num_fds; n++) fds[n].revents = (map[n] < 0 && r >= 0) ? 0 : p_fds[map[n]].revents; return r;}
int mp_subprocess(char **args, struct mp_cancel *cancel, void *ctx, subprocess_read_cb on_stdout, subprocess_read_cb on_stderr, char **error){ posix_spawn_file_actions_t fa; bool fa_destroy = false; int status = -1; int p_stdout[2] = {-1, -1}; int p_stderr[2] = {-1, -1}; int devnull = -1; pid_t pid = -1; bool spawned = false; bool killed_by_us = false;
if (on_stdout && mp_make_cloexec_pipe(p_stdout) < 0) goto done; if (on_stderr && mp_make_cloexec_pipe(p_stderr) < 0) goto done;
devnull = open("/dev/null", O_RDONLY | O_CLOEXEC); if (devnull < 0) goto done;
if (posix_spawn_file_actions_init(&fa)) goto done; fa_destroy = true; // redirect stdin/stdout/stderr if (posix_spawn_file_actions_adddup2(&fa, devnull, 0)) goto done; if (p_stdout[1] >= 0 && posix_spawn_file_actions_adddup2(&fa, p_stdout[1], 1)) goto done; if (p_stderr[1] >= 0 && posix_spawn_file_actions_adddup2(&fa, p_stderr[1], 2)) goto done;
if (posix_spawnp(&pid, args[0], &fa, NULL, args, environ)) { pid = -1; goto done; } spawned = true;
SAFE_CLOSE(p_stdout[1]); SAFE_CLOSE(p_stderr[1]); SAFE_CLOSE(devnull);
int *read_fds[2] = {&p_stdout[0], &p_stderr[0]}; subprocess_read_cb read_cbs[2] = {on_stdout, on_stderr};
while (p_stdout[0] >= 0 || p_stderr[0] >= 0) { struct pollfd fds[] = { {.events = POLLIN, .fd = *read_fds[0]}, {.events = POLLIN, .fd = *read_fds[1]}, {.events = POLLIN, .fd = cancel ? mp_cancel_get_fd(cancel) : -1}, }; if (sparse_poll(fds, MP_ARRAY_SIZE(fds), -1) < 0 && errno != EINTR) break; for (int n = 0; n < 2; n++) { if (fds[n].revents) { char buf[4096]; ssize_t r = read(*read_fds[n], buf, sizeof(buf)); if (r < 0 && errno == EINTR) continue; if (r > 0 && read_cbs[n]) read_cbs[n](ctx, buf, r); if (r <= 0) SAFE_CLOSE(*read_fds[n]); } } if (fds[2].revents) { kill(pid, SIGKILL); killed_by_us = true; break; } }
// Note: it can happen that a child process closes the pipe, but does not // terminate yet. In this case, we would have to run waitpid() in // a separate thread and use pthread_cancel(), or use other weird // and laborious tricks. So this isn't handled yet. while (waitpid(pid, &status, 0) < 0 && errno == EINTR) {}
done: if (fa_destroy) posix_spawn_file_actions_destroy(&fa); SAFE_CLOSE(p_stdout[0]); SAFE_CLOSE(p_stdout[1]); SAFE_CLOSE(p_stderr[0]); SAFE_CLOSE(p_stderr[1]); SAFE_CLOSE(devnull);
if (!spawned || (WIFEXITED(status) && WEXITSTATUS(status) == 127)) { *error = "init"; status = -1; } else if (WIFEXITED(status)) { *error = NULL; status = WEXITSTATUS(status); } else { *error = "killed"; status = killed_by_us ? MP_SUBPROCESS_EKILLED_BY_US : -1; }
return status;}