mirror of
https://github.com/alsa-project/alsa-utils
synced 2024-11-08 22:05:41 +01:00
b402cf543a
See 'man 7 alsactl_init' for more details. Signed-off-by: Jaroslav Kysela <perex@perex.cz>
247 lines
6.3 KiB
C
247 lines
6.3 KiB
C
/*
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* Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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*/
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#define MY_MAX(a,b) ((a) > (b) ? (a) : (b))
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#define READ_END 0
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#define WRITE_END 1
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static
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int run_program1(struct space *space,
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const char *command0, char *result,
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size_t ressize, size_t *reslen, int log);
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static
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int run_program0(struct space *space,
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const char *command0, char *result,
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size_t ressize, size_t *reslen, int log)
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{
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int retval = 0;
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int status;
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int outpipe[2] = {-1, -1};
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int errpipe[2] = {-1, -1};
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pid_t pid;
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char arg[PATH_SIZE];
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char program[PATH_SIZE];
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char *argv[(sizeof(arg) / 2) + 1];
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int devnull;
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int i;
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/* build argv from comand */
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strlcpy(arg, command0, sizeof(arg));
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i = 0;
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if (strchr(arg, ' ') != NULL) {
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char *pos = arg;
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while (pos != NULL) {
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if (pos[0] == '\'') {
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/* don't separate if in apostrophes */
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pos++;
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argv[i] = strsep(&pos, "\'");
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while (pos != NULL && pos[0] == ' ')
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pos++;
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} else {
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argv[i] = strsep(&pos, " ");
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}
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dbg("arg[%i] '%s'", i, argv[i]);
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i++;
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}
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argv[i] = NULL;
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} else {
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argv[0] = arg;
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argv[1] = NULL;
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}
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info("'%s'", command0);
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/* prepare pipes from child to parent */
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if (result || log) {
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if (pipe(outpipe) != 0) {
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Perror(space, "pipe failed: %s", strerror(errno));
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return -1;
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}
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}
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if (log) {
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if (pipe(errpipe) != 0) {
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Perror(space, "pipe failed: %s", strerror(errno));
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return -1;
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}
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}
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/* allow programs in /lib/alsa called without the path */
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if (strchr(argv[0], '/') == NULL) {
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strlcpy(program, "/lib/alsa/", sizeof(program));
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strlcat(program, argv[0], sizeof(program));
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argv[0] = program;
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}
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pid = fork();
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switch(pid) {
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case 0:
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/* child closes parent ends of pipes */
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if (outpipe[READ_END] > 0)
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close(outpipe[READ_END]);
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if (errpipe[READ_END] > 0)
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close(errpipe[READ_END]);
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/* discard child output or connect to pipe */
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devnull = open("/dev/null", O_RDWR);
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if (devnull > 0) {
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dup2(devnull, STDIN_FILENO);
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if (outpipe[WRITE_END] < 0)
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dup2(devnull, STDOUT_FILENO);
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if (errpipe[WRITE_END] < 0)
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dup2(devnull, STDERR_FILENO);
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close(devnull);
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} else
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Perror(space, "open /dev/null failed: %s", strerror(errno));
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if (outpipe[WRITE_END] > 0) {
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dup2(outpipe[WRITE_END], STDOUT_FILENO);
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close(outpipe[WRITE_END]);
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}
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if (errpipe[WRITE_END] > 0) {
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dup2(errpipe[WRITE_END], STDERR_FILENO);
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close(errpipe[WRITE_END]);
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}
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execv(argv[0], argv);
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/* we should never reach this */
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Perror(space, "exec of program '%s' failed", argv[0]);
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_exit(1);
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case -1:
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Perror(space, "fork of '%s' failed: %s", argv[0], strerror(errno));
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return -1;
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default:
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/* read from child if requested */
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if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
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ssize_t count;
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size_t respos = 0;
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/* parent closes child ends of pipes */
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if (outpipe[WRITE_END] > 0)
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close(outpipe[WRITE_END]);
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if (errpipe[WRITE_END] > 0)
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close(errpipe[WRITE_END]);
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/* read child output */
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while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
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int fdcount;
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fd_set readfds;
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FD_ZERO(&readfds);
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if (outpipe[READ_END] > 0)
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FD_SET(outpipe[READ_END], &readfds);
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if (errpipe[READ_END] > 0)
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FD_SET(errpipe[READ_END], &readfds);
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fdcount = select(MY_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
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if (fdcount < 0) {
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if (errno == EINTR)
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continue;
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retval = -1;
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break;
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}
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/* get stdout */
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if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
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char inbuf[1024];
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char *pos;
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char *line;
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count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
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if (count <= 0) {
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close(outpipe[READ_END]);
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outpipe[READ_END] = -1;
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if (count < 0) {
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Perror(space, "stdin read failed: %s", strerror(errno));
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retval = -1;
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}
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continue;
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}
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inbuf[count] = '\0';
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/* store result for rule processing */
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if (result) {
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if (respos + count < ressize) {
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memcpy(&result[respos], inbuf, count);
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respos += count;
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} else {
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Perror(space, "ressize %ld too short", (long)ressize);
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retval = -1;
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}
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}
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pos = inbuf;
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while ((line = strsep(&pos, "\n")))
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if (pos || line[0] != '\0')
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info("'%s' (stdout) '%s'", argv[0], line);
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}
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/* get stderr */
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if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
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char errbuf[1024];
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char *pos;
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char *line;
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count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
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if (count <= 0) {
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close(errpipe[READ_END]);
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errpipe[READ_END] = -1;
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if (count < 0)
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Perror(space, "stderr read failed: %s", strerror(errno));
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continue;
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}
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errbuf[count] = '\0';
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pos = errbuf;
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while ((line = strsep(&pos, "\n")))
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if (pos || line[0] != '\0')
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info("'%s' (stderr) '%s'", argv[0], line);
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}
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}
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if (outpipe[READ_END] > 0)
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close(outpipe[READ_END]);
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if (errpipe[READ_END] > 0)
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close(errpipe[READ_END]);
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/* return the childs stdout string */
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if (result) {
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result[respos] = '\0';
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dbg("result='%s'", result);
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if (reslen)
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*reslen = respos;
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}
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}
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waitpid(pid, &status, 0);
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if (WIFEXITED(status)) {
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info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
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if (WEXITSTATUS(status) != 0)
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retval = -1;
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} else {
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Perror(space, "'%s' abnormal exit", argv[0]);
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retval = -1;
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}
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}
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return retval;
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}
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static
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int run_program(struct space *space, const char *command0, char *result,
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size_t ressize, size_t *reslen, int log)
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{
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if (command0[0] == '_' && command0[1] == '_')
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return run_program1(space, command0, result, ressize, reslen, log);
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return run_program0(space, command0, result, ressize, reslen, log);
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}
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