+#ifndef UTMP_FILE
+#define UTMP_FILE "/var/run/utmp"
+#endif
+#ifndef WTMP_FILE
+#define WTMP_FILE "/var/log/wtmp"
+#endif
+#ifndef LASTLOG_FILE
+#ifdef _PATH_LASTLOG
+#define LASTLOG_FILE _PATH_LASTLOG
+#else
+#define LASTLOG_FILE "/var/log/lastlog"
+#endif
+#endif
+
+/*
+ * Set up a default for vaguely sane systems. The idea is that if
+ * OMIT_UTMP is not defined, then at least one of the symbols which
+ * enable particular forms of utmp processing should be, if only so
+ * that a link error can warn you that you should have defined
+ * OMIT_UTMP if you didn't want any. Currently HAVE_PUTUTLINE is
+ * the only such symbol.
+ */
+#ifndef OMIT_UTMP
+#if !defined HAVE_PUTUTLINE
+#define HAVE_PUTUTLINE
+#endif
+#endif
+
+int pty_master_fd;
+static void *pty_frontend;
+static char pty_name[FILENAME_MAX];
+static int pty_stamped_utmp = 0;
+static int pty_child_pid;
+static int pty_utmp_helper_pid, pty_utmp_helper_pipe;
+static int pty_term_width, pty_term_height;
+static sig_atomic_t pty_child_dead;
+static int pty_exit_code;
+#ifndef OMIT_UTMP
+static struct utmp utmp_entry;
+#endif
+char **pty_argv;
+
+static void setup_utmp(char *ttyname, char *location)
+{
+#ifndef OMIT_UTMP
+#ifdef HAVE_LASTLOG
+ struct lastlog lastlog_entry;
+ FILE *lastlog;
+#endif
+ struct passwd *pw;
+ FILE *wtmp;
+
+ pw = getpwuid(getuid());
+ memset(&utmp_entry, 0, sizeof(utmp_entry));
+ utmp_entry.ut_type = USER_PROCESS;
+ utmp_entry.ut_pid = getpid();
+ strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line));
+ strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id));
+ strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user));
+ strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host));
+ time(&utmp_entry.ut_time);
+
+#if defined HAVE_PUTUTLINE
+ utmpname(UTMP_FILE);
+ setutent();
+ pututline(&utmp_entry);
+ endutent();
+#endif
+
+ if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
+ fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
+ fclose(wtmp);
+ }
+
+#ifdef HAVE_LASTLOG
+ memset(&lastlog_entry, 0, sizeof(lastlog_entry));
+ strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line));
+ strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host));
+ time(&lastlog_entry.ll_time);
+ if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) {
+ fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET);
+ fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog);
+ fclose(lastlog);
+ }
+#endif
+
+ pty_stamped_utmp = 1;
+
+#endif
+}
+
+static void cleanup_utmp(void)
+{
+#ifndef OMIT_UTMP
+ FILE *wtmp;
+
+ if (!pty_stamped_utmp)
+ return;
+
+ utmp_entry.ut_type = DEAD_PROCESS;
+ memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user));
+ time(&utmp_entry.ut_time);
+
+ if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
+ fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
+ fclose(wtmp);
+ }
+
+ memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line));
+ utmp_entry.ut_time = 0;
+
+#if defined HAVE_PUTUTLINE
+ utmpname(UTMP_FILE);
+ setutent();
+ pututline(&utmp_entry);
+ endutent();
+#endif
+
+ pty_stamped_utmp = 0; /* ensure we never double-cleanup */
+#endif
+}
+
+static void sigchld_handler(int signum)
+{
+ pid_t pid;
+ int status;
+ pid = waitpid(-1, &status, WNOHANG);
+ if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status))) {
+ pty_exit_code = status;
+ pty_child_dead = TRUE;
+ }
+}
+
+static void fatal_sig_handler(int signum)
+{
+ signal(signum, SIG_DFL);
+ cleanup_utmp();
+ setuid(getuid());
+ raise(signum);
+}
+
+static void pty_open_master(void)
+{
+#ifdef BSD_PTYS
+ const char chars1[] = "pqrstuvwxyz";
+ const char chars2[] = "0123456789abcdef";
+ const char *p1, *p2;
+ char master_name[20];
+ struct group *gp;
+
+ 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);