A fast, lightweight and minimalistic Wayland terminal emulator
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

185 lines
5.2 KiB

#include "spawn.h"
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define LOG_MODULE "spawn"
#define LOG_ENABLE_DBG 0
#include "log.h"
#include "debug.h"
#include "xmalloc.h"
bool
spawn(struct reaper *reaper, const char *cwd, char *const argv[],
int stdin_fd, int stdout_fd, int stderr_fd)
{
int pipe_fds[2] = {-1, -1};
if (pipe2(pipe_fds, O_CLOEXEC) < 0) {
LOG_ERRNO("failed to create pipe");
goto err;
}
pid_t pid = fork();
if (pid < 0) {
LOG_ERRNO("failed to fork");
goto err;
}
if (pid == 0) {
/* Child */
close(pipe_fds[0]);
if (setsid() < 0)
goto child_err;
/* Clear signal mask */
sigset_t mask;
sigemptyset(&mask);
if (sigprocmask(SIG_SETMASK, &mask, NULL) < 0)
goto child_err;
/* Restore ignored (SIG_IGN) signals */
if (sigaction(SIGHUP, &(struct sigaction){.sa_handler = SIG_DFL}, NULL) < 0)
goto child_err;
bool close_stderr = stderr_fd >= 0;
bool close_stdout = stdout_fd >= 0 && stdout_fd != stderr_fd;
bool close_stdin = stdin_fd >= 0 && stdin_fd != stdout_fd && stdin_fd != stderr_fd;
if ((stdin_fd >= 0 && (dup2(stdin_fd, STDIN_FILENO) < 0
|| (close_stdin && close(stdin_fd) < 0))) ||
(stdout_fd >= 0 && (dup2(stdout_fd, STDOUT_FILENO) < 0
|| (close_stdout && close(stdout_fd) < 0))) ||
(stderr_fd >= 0 && (dup2(stderr_fd, STDERR_FILENO) < 0
|| (close_stderr && close(stderr_fd) < 0))) ||
(cwd != NULL && chdir(cwd) < 0) ||
execvp(argv[0], argv) < 0)
{
goto child_err;
}
xassert(false);
_exit(errno);
child_err:
;
const int errno_copy = errno;
(void)!write(pipe_fds[1], &errno_copy, sizeof(errno_copy));
_exit(errno_copy);
}
/* Parent */
close(pipe_fds[1]);
int errno_copy;
static_assert(sizeof(errno_copy) == sizeof(errno), "errno size mismatch");
ssize_t ret = read(pipe_fds[0], &errno_copy, sizeof(errno_copy));
close(pipe_fds[0]);
if (ret == 0) {
reaper_add(reaper, pid, NULL, NULL);
return true;
} else if (ret < 0) {
LOG_ERRNO("failed to read from pipe");
return false;
} else {
LOG_ERRNO_P(errno_copy, "%s: failed to spawn", argv[0]);
errno = errno_copy;
waitpid(pid, NULL, 0);
return false;
}
err:
if (pipe_fds[0] != -1)
close(pipe_fds[0]);
if (pipe_fds[1] != -1)
close(pipe_fds[1]);
return false;
}
bool
spawn_expand_template(const struct config_spawn_template *template,
size_t key_count,
const char *key_names[static key_count],
const char *key_values[static key_count],
size_t *argc, char ***argv)
{
*argc = 0;
*argv = NULL;
for (; template->argv.args[*argc] != NULL; (*argc)++)
;
#define append(s, n) \
do { \
expanded = xrealloc(expanded, len + (n) + 1); \
memcpy(&expanded[len], s, n); \
len += n; \
expanded[len] = '\0'; \
} while (0)
*argv = malloc((*argc + 1) * sizeof((*argv)[0]));
/* Expand the provided keys */
for (size_t i = 0; i < *argc; i++) {
size_t len = 0;
char *expanded = NULL;
char *start = NULL;
char *last_end = template->argv.args[i];
while ((start = strstr(last_end, "${")) != NULL) {
/* Append everything from the last template's end to this
* one's beginning */
append(last_end, start - last_end);
/* Find end of template */
start += 2;
char *end = strstr(start, "}");
if (end == NULL) {
/* Ensure final append() copies the unclosed '${' */
last_end = start - 2;
LOG_WARN("notify: unclosed template: %s", last_end);
break;
}
/* Expand template */
bool valid_key = false;
for (size_t j = 0; j < key_count; j++) {
if (strncmp(start, key_names[j], end - start) != 0)
continue;
append(key_values[j], strlen(key_values[j]));
valid_key = true;
break;
}
if (!valid_key) {
/* Unrecognized template - append it as-is */
start -= 2;
append(start, end + 1 - start);
LOG_WARN("notify: unrecognized template: %.*s",
(int)(end + 1 - start), start);
}
last_end = end + 1;
}
append(
last_end,
template->argv.args[i] + strlen(template->argv.args[i]) - last_end);
(*argv)[i] = expanded;
}
(*argv)[*argc] = NULL;
#undef append
return true;
}