+ int slavefd;
+ char name[FILENAME_MAX];
+ pid_t pid, pgrp;
+
+#ifdef BSD_PTYS
+ {
+ const char chars1[] = "pqrstuvwxyz";
+ const char chars2[] = "0123456789abcdef";
+ const char *p1, *p2;
+ char master_name[20];
+
+ for (p1 = chars1; *p1; p1++)
+ for (p2 = chars2; *p2; p2++) {
+ sprintf(master_name, "/dev/pty%c%c", *p1, *p2);
+ pty_master_fd = open(master_name, O_RDWR);
+ if (pty_master_fd >= 0) {
+ if (geteuid() == 0 ||
+ access(master_name, R_OK | W_OK) == 0)
+ goto got_one;
+ close(pty_master_fd);
+ }
+ }
+
+ /* If we get here, we couldn't get a tty at all. */
+ fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n");
+ exit(1);
+
+ got_one:
+ strcpy(name, master_name);
+ name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */
+ }
+#else
+ pty_master_fd = open("/dev/ptmx", O_RDWR);
+
+ if (pty_master_fd < 0) {
+ perror("/dev/ptmx: open");
+ exit(1);
+ }
+
+ if (grantpt(pty_master_fd) < 0) {
+ perror("grantpt");
+ exit(1);
+ }
+
+ if (unlockpt(pty_master_fd) < 0) {
+ perror("unlockpt");
+ exit(1);
+ }
+
+ name[FILENAME_MAX-1] = '\0';
+ strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1);
+#endif
+
+ /*
+ * Set the backspace character to be whichever of ^H and ^? is
+ * specified by bksp_is_delete.
+ */
+ {
+ struct termios attrs;
+ tcgetattr(pty_master_fd, &attrs);
+ attrs.c_cc[VERASE] = cfg.bksp_is_delete ? '\177' : '\010';
+ tcsetattr(pty_master_fd, TCSANOW, &attrs);
+ }
+
+ /*
+ * Trap as many fatal signals as we can in the hope of having
+ * the best chance to clean up utmp before termination.
+ */
+ signal(SIGHUP, fatal_sig_handler);
+ signal(SIGINT, fatal_sig_handler);
+ signal(SIGQUIT, fatal_sig_handler);
+ signal(SIGILL, fatal_sig_handler);
+ signal(SIGABRT, fatal_sig_handler);
+ signal(SIGFPE, fatal_sig_handler);
+ signal(SIGPIPE, fatal_sig_handler);
+ signal(SIGALRM, fatal_sig_handler);
+ signal(SIGTERM, fatal_sig_handler);
+ signal(SIGSEGV, fatal_sig_handler);
+ signal(SIGUSR1, fatal_sig_handler);
+ signal(SIGUSR2, fatal_sig_handler);
+#ifdef SIGBUS
+ signal(SIGBUS, fatal_sig_handler);
+#endif
+#ifdef SIGPOLL
+ signal(SIGPOLL, fatal_sig_handler);
+#endif
+#ifdef SIGPROF
+ signal(SIGPROF, fatal_sig_handler);
+#endif
+#ifdef SIGSYS
+ signal(SIGSYS, fatal_sig_handler);
+#endif
+#ifdef SIGTRAP
+ signal(SIGTRAP, fatal_sig_handler);
+#endif
+#ifdef SIGVTALRM
+ signal(SIGVTALRM, fatal_sig_handler);
+#endif
+#ifdef SIGXCPU
+ signal(SIGXCPU, fatal_sig_handler);
+#endif
+#ifdef SIGXFSZ
+ signal(SIGXFSZ, fatal_sig_handler);
+#endif
+#ifdef SIGIO
+ signal(SIGIO, fatal_sig_handler);
+#endif
+ /* Also clean up utmp on normal exit. */
+ atexit(cleanup_utmp);
+ setup_utmp(name);
+
+ /*
+ * Fork and execute the command.
+ */
+ pid = fork();
+ if (pid < 0) {
+ perror("fork");
+ exit(1);
+ }
+
+ if (pid == 0) {
+ int i;
+ /*
+ * We are the child.
+ */
+
+ slavefd = open(name, O_RDWR);
+ if (slavefd < 0) {
+ perror("slave pty: open");
+ exit(1);
+ }
+
+#ifdef BSD_PTYS
+ /* We need to chown/chmod the /dev/ttyXX device. */
+ {
+ struct group *gp = getgrnam("tty");
+ fchown(slavefd, getuid(), gp ? gp->gr_gid : -1);
+ fchmod(slavefd, 0600);
+ }
+#endif
+
+ close(pty_master_fd);
+ close(0);
+ close(1);
+ close(2);
+ fcntl(slavefd, F_SETFD, 0); /* don't close on exec */
+ dup2(slavefd, 0);
+ dup2(slavefd, 1);
+ dup2(slavefd, 2);
+ setsid();
+ ioctl(slavefd, TIOCSCTTY, 1);
+ pgrp = getpid();
+ tcsetpgrp(slavefd, pgrp);
+ setpgrp();
+ close(open(name, O_WRONLY, 0));
+ setpgrp();
+ /* In case we were setgid-utmp or setuid-root, drop privs. */
+ setgid(getgid());
+ setuid(getuid());
+ /* Close everything _else_, for tidiness. */
+ for (i = 3; i < 1024; i++)
+ close(i);
+ {
+ char term_env_var[10 + sizeof(cfg.termtype)];
+ sprintf(term_env_var, "TERM=%s", cfg.termtype);
+ putenv(term_env_var);
+ }
+ if (pty_argv)
+ execvp(pty_argv[0], pty_argv);
+ else {
+ char *shell = getenv("SHELL");
+ char *shellname;
+ if (cfg.login_shell) {
+ char *p = strrchr(shell, '/');
+ shellname = smalloc(2+strlen(shell));
+ p = p ? p+1 : shell;
+ sprintf(shellname, "-%s", p);
+ } else
+ shellname = shell;
+ execl(getenv("SHELL"), shellname, NULL);
+ }
+
+ /*
+ * If we're here, exec has gone badly foom.
+ */
+ perror("exec");
+ exit(127);
+ } else {
+ close(slavefd);
+ pty_child_pid = pid;
+ pty_child_dead = FALSE;
+ signal(SIGCHLD, sigchld_handler);
+ }
+