/* Create pty and fork/exec target process */
pid_t exec_target(int master_fd, char* argv[], int pty_alloc_only)
{
pid_t pid;
pid = fork();
if (pid < 0) {
perror("Failed to fork");
exit(EXIT_FAILURE);
}
if (pid == 0) {
int slave_fd;
int i;
/* new session for obtain ctty */
if (setsid() < 0) {
perror("Failed to setsid");
exit(EXIT_FAILURE);
}
slave_fd = open(ptsname(master_fd), O_RDWR);
close(master_fd);
if (slave_fd < 0) {
perror("Failed to open slave pty");
exit(EXIT_FAILURE);
}
if (pty_alloc_only)
set_tty_echo_on(slave_fd);
for (i = 0; i < 3; i++) {
if (slave_fd != i) {
dup2(slave_fd, i);
fcntl(i, F_SETFD, 0);
}
}
if (slave_fd > 2)
close(slave_fd);
/* make new process group and make it foreground */
if (setpgid(0, 0) < 0)
perror("Failed to setpgid");
if (tcsetpgrp(0, getpgid(getpid())) < 0)
perror("Failed to change foreground pgid");
if (pty_alloc_only)
/* do nothing. wait for kill */
select(0, NULL, NULL, NULL, NULL);
else
execvp(argv[0], argv);
fprintf(stderr, "Failed to execute \"%s\": %s\n", argv[0], strerror(errno));
exit(EXIT_FAILURE);
}
return pid;
}
int main(int argc, char* argv[])
{
fd_set sel, sel0;
int status;
int pty_hold_mode = FALSE;
char* newarg0;
/* SIGINT and SIGBREAK are indistinctive under cygwin environment. */
/* Using Win32API to handle SIGINT. */
SetConsoleCtrlHandler(ctrl_handler, TRUE);
if (argc < 1) {
fputs("Unable to get arg[0].", stderr);
exit(EXIT_FAILURE);
}
newarg0 = real_command_name(argv[0]);
if (newarg0)
argv[0] = newarg0;
else if (argc >=2)
argv++;
else
pty_hold_mode = TRUE;
if (isatty(STDIN_FILENO) && !pty_hold_mode) {
execvp(argv[0], argv);
fprintf(stderr, "Failed to execute \"%s\": %s\n", argv[0], strerror(errno));
exit(EXIT_FAILURE);
}
masterfd = open_master_pty();
if (!pty_hold_mode)
child_pid = exec_target(masterfd, argv);
else
set_tty_echo_on(masterfd);
setup_signal_handlers();
FD_ZERO(&sel0);
FD_SET(masterfd, &sel0);
FD_SET(STDIN_FILENO, &sel0);
/* communication loop */
while (1) {
char buf[BUFSIZE];
int ret;
if (sig_winch_caught == TRUE) {
sig_winch_caught = FALSE;
if (child_pid != -1 && resize_tty_window(masterfd, sig_window_size) == 0)
kill(child_pid, SIGWINCH);
}
sel = sel0;
if (select (FD_SETSIZE, &sel, NULL, NULL, NULL) <= 0) {
if(errno == EINTR)
continue;
else
break;
}
if (FD_ISSET(masterfd, &sel)) {
ret = safe_read(masterfd, buf, BUFSIZE);
if (ret > 0) {
if (safe_write_full(STDOUT_FILENO, buf, ret) < 0)
break;
}
else
break;
}
else if (FD_ISSET(STDIN_FILENO, &sel)) {
ret = safe_read(STDIN_FILENO, buf, BUFSIZE);
if (ret > 0) {
if (safe_write_full_checking_eof(masterfd, buf, ret) < 0)
break;
} else {
FD_CLR(STDIN_FILENO, &sel0);
close(masterfd);
}
}
}
if (pty_hold_mode) {
status = 0;
} else {
while(waitpid(child_pid, &status, 0) < 0 && errno == EINTR)
;
if (WIFEXITED(status))
status = WEXITSTATUS(status);
else if(WIFSIGNALED(status)) /* ntemacs cannot distinct killed by signal */
status = 0x80 + WTERMSIG(status);
}
return status;
}
