1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright 2010 Lennart Poettering
9 //#include <linux/kd.h>
10 //#include <linux/tiocl.h>
11 //#include <linux/vt.h>
18 #include <sys/inotify.h>
19 //#include <sys/ioctl.h>
20 #include <sys/socket.h>
21 #include <sys/sysmacros.h>
23 #include <sys/types.h>
24 //#include <sys/utsname.h>
28 #include "alloc-util.h"
39 #include "parse-util.h"
40 //#include "path-util.h"
41 //#include "proc-cmdline.h"
42 #include "process-util.h"
43 #include "socket-util.h"
44 #include "stat-util.h"
45 #include "string-util.h"
47 #include "terminal-util.h"
48 #include "time-util.h"
51 /// Additional includes needed by elogind
52 #include "path-util.h"
54 static volatile unsigned cached_columns = 0;
55 static volatile unsigned cached_lines = 0;
57 static volatile int cached_on_tty = -1;
58 static volatile int cached_colors_enabled = -1;
59 static volatile int cached_underline_enabled = -1;
62 _cleanup_close_ int fd;
64 /* Switch to the specified vt number. If the VT is specified <= 0 switch to the VT the kernel log messages go,
65 * if that's configured. */
67 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
73 TIOCL_GETKMSGREDIRECT,
77 if (ioctl(fd, TIOCLINUX, tiocl) < 0)
80 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
83 if (ioctl(fd, VT_ACTIVATE, vt) < 0)
89 #if 0 /// UNNEEDED by elogind
90 int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
91 struct termios old_termios, new_termios;
92 char c, line[LINE_MAX];
97 if (tcgetattr(fileno(f), &old_termios) >= 0) {
98 new_termios = old_termios;
100 new_termios.c_lflag &= ~ICANON;
101 new_termios.c_cc[VMIN] = 1;
102 new_termios.c_cc[VTIME] = 0;
104 if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
107 if (t != USEC_INFINITY) {
108 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
109 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
114 k = fread(&c, 1, 1, f);
116 tcsetattr(fileno(f), TCSADRAIN, &old_termios);
122 *need_nl = c != '\n';
129 if (t != USEC_INFINITY) {
130 if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
135 if (!fgets(line, sizeof(line), f))
136 return errno > 0 ? -errno : -EIO;
140 if (strlen(line) != 1)
150 #define DEFAULT_ASK_REFRESH_USEC (2*USEC_PER_SEC)
152 int ask_char(char *ret, const char *replies, const char *fmt, ...) {
164 if (colors_enabled())
165 fputs(ANSI_HIGHLIGHT, stdout);
173 if (colors_enabled())
174 fputs(ANSI_NORMAL, stdout);
178 r = read_one_char(stdin, &c, DEFAULT_ASK_REFRESH_USEC, &need_nl);
185 puts("Bad input, please try again.");
196 if (strchr(replies, c)) {
201 puts("Read unexpected character, please try again.");
205 int ask_string(char **ret, const char *text, ...) {
213 if (colors_enabled())
214 fputs(ANSI_HIGHLIGHT, stdout);
220 if (colors_enabled())
221 fputs(ANSI_NORMAL, stdout);
226 if (!fgets(line, sizeof(line), stdin))
227 return errno > 0 ? -errno : -EIO;
229 if (!endswith(line, "\n"))
248 int reset_terminal_fd(int fd, bool switch_to_text) {
249 struct termios termios;
252 /* Set terminal to some sane defaults */
256 /* We leave locked terminal attributes untouched, so that
257 * Plymouth may set whatever it wants to set, and we don't
258 * interfere with that. */
260 /* Disable exclusive mode, just in case */
261 (void) ioctl(fd, TIOCNXCL);
263 /* Switch to text mode */
265 (void) ioctl(fd, KDSETMODE, KD_TEXT);
267 /* Set default keyboard mode */
268 (void) vt_reset_keyboard(fd);
270 if (tcgetattr(fd, &termios) < 0) {
275 /* We only reset the stuff that matters to the software. How
276 * hardware is set up we don't touch assuming that somebody
277 * else will do that for us */
279 termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
280 termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
281 termios.c_oflag |= ONLCR;
282 termios.c_cflag |= CREAD;
283 termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
285 termios.c_cc[VINTR] = 03; /* ^C */
286 termios.c_cc[VQUIT] = 034; /* ^\ */
287 termios.c_cc[VERASE] = 0177;
288 termios.c_cc[VKILL] = 025; /* ^X */
289 termios.c_cc[VEOF] = 04; /* ^D */
290 termios.c_cc[VSTART] = 021; /* ^Q */
291 termios.c_cc[VSTOP] = 023; /* ^S */
292 termios.c_cc[VSUSP] = 032; /* ^Z */
293 termios.c_cc[VLNEXT] = 026; /* ^V */
294 termios.c_cc[VWERASE] = 027; /* ^W */
295 termios.c_cc[VREPRINT] = 022; /* ^R */
296 termios.c_cc[VEOL] = 0;
297 termios.c_cc[VEOL2] = 0;
299 termios.c_cc[VTIME] = 0;
300 termios.c_cc[VMIN] = 1;
302 if (tcsetattr(fd, TCSANOW, &termios) < 0)
306 /* Just in case, flush all crap out */
307 (void) tcflush(fd, TCIOFLUSH);
312 int reset_terminal(const char *name) {
313 _cleanup_close_ int fd = -1;
315 /* We open the terminal with O_NONBLOCK here, to ensure we
316 * don't block on carrier if this is a terminal with carrier
319 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
323 return reset_terminal_fd(fd, true);
327 int open_terminal(const char *name, int mode) {
332 * If a TTY is in the process of being closed opening it might
333 * cause EIO. This is horribly awful, but unlikely to be
334 * changed in the kernel. Hence we work around this problem by
335 * retrying a couple of times.
337 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
344 fd = open(name, mode, 0);
351 /* Max 1s in total */
355 usleep(50 * USEC_PER_MSEC);
359 if (isatty(fd) <= 0) {
367 #if 0 /// UNNEEDED by elogind
368 int acquire_terminal(
370 AcquireTerminalFlags flags,
373 _cleanup_close_ int notify = -1, fd = -1;
374 usec_t ts = USEC_INFINITY;
378 assert(IN_SET(flags & ~ACQUIRE_TERMINAL_PERMISSIVE, ACQUIRE_TERMINAL_TRY, ACQUIRE_TERMINAL_FORCE, ACQUIRE_TERMINAL_WAIT));
380 /* We use inotify to be notified when the tty is closed. We create the watch before checking if we can actually
381 * acquire it, so that we don't lose any event.
383 * Note: strictly speaking this actually watches for the device being closed, it does *not* really watch
384 * whether a tty loses its controlling process. However, unless some rogue process uses TIOCNOTTY on /dev/tty
385 * *after* closing its tty otherwise this will not become a problem. As long as the administrator makes sure to
386 * not configure any service on the same tty as an untrusted user this should not be a problem. (Which they
387 * probably should not do anyway.) */
389 if ((flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_WAIT) {
390 notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
394 wd = inotify_add_watch(notify, name, IN_CLOSE);
398 if (timeout != USEC_INFINITY)
399 ts = now(CLOCK_MONOTONIC);
403 struct sigaction sa_old, sa_new = {
404 .sa_handler = SIG_IGN,
405 .sa_flags = SA_RESTART,
409 r = flush_fd(notify);
414 /* We pass here O_NOCTTY only so that we can check the return value TIOCSCTTY and have a reliable way
415 * to figure out if we successfully became the controlling process of the tty */
416 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
420 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed if we already own the tty. */
421 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
423 /* First, try to get the tty */
424 r = ioctl(fd, TIOCSCTTY,
425 (flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_FORCE) < 0 ? -errno : 0;
427 /* Reset signal handler to old value */
428 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
430 /* Success? Exit the loop now! */
434 /* Any failure besides -EPERM? Fail, regardless of the mode. */
438 if (flags & ACQUIRE_TERMINAL_PERMISSIVE) /* If we are in permissive mode, then EPERM is fine, turn this
439 * into a success. Note that EPERM is also returned if we
440 * already are the owner of the TTY. */
443 if (flags != ACQUIRE_TERMINAL_WAIT) /* If we are in TRY or FORCE mode, then propagate EPERM as EPERM */
450 union inotify_event_buffer buffer;
451 struct inotify_event *e;
454 if (timeout != USEC_INFINITY) {
457 assert(ts != USEC_INFINITY);
459 n = now(CLOCK_MONOTONIC);
460 if (ts + timeout < n)
463 r = fd_wait_for_event(notify, POLLIN, ts + timeout - n);
470 l = read(notify, &buffer, sizeof(buffer));
472 if (IN_SET(errno, EINTR, EAGAIN))
478 FOREACH_INOTIFY_EVENT(e, buffer, l) {
479 if (e->mask & IN_Q_OVERFLOW) /* If we hit an inotify queue overflow, simply check if the terminal is up for grabs now. */
482 if (e->wd != wd || !(e->mask & IN_CLOSE)) /* Safety checks */
489 /* We close the tty fd here since if the old session ended our handle will be dead. It's important that
490 * we do this after sleeping, so that we don't enter an endless loop. */
498 #if 0 /// UNNEEDED by elogind
499 int release_terminal(void) {
500 static const struct sigaction sa_new = {
501 .sa_handler = SIG_IGN,
502 .sa_flags = SA_RESTART,
505 _cleanup_close_ int fd = -1;
506 struct sigaction sa_old;
509 fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
513 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
514 * by our own TIOCNOTTY */
515 assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
517 r = ioctl(fd, TIOCNOTTY) < 0 ? -errno : 0;
519 assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
524 int terminal_vhangup_fd(int fd) {
527 if (ioctl(fd, TIOCVHANGUP) < 0)
533 int terminal_vhangup(const char *name) {
534 _cleanup_close_ int fd;
536 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
540 return terminal_vhangup_fd(fd);
543 int vt_disallocate(const char *name) {
544 _cleanup_close_ int fd = -1;
549 /* Deallocate the VT if possible. If not possible
550 * (i.e. because it is the active one), at least clear it
551 * entirely (including the scrollback buffer) */
553 e = path_startswith(name, "/dev/");
557 if (!tty_is_vc(name)) {
558 /* So this is not a VT. I guess we cannot deallocate
559 * it then. But let's at least clear the screen */
561 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
566 "\033[r" /* clear scrolling region */
567 "\033[H" /* move home */
568 "\033[2J", /* clear screen */
573 n = startswith(e, "tty");
577 r = safe_atou(n, &u);
584 /* Try to deallocate */
585 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
589 r = ioctl(fd, VT_DISALLOCATE, u);
598 /* Couldn't deallocate, so let's clear it fully with
600 fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
605 "\033[r" /* clear scrolling region */
606 "\033[H" /* move home */
607 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
612 int make_console_stdio(void) {
615 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
617 fd = acquire_terminal("/dev/console", ACQUIRE_TERMINAL_FORCE|ACQUIRE_TERMINAL_PERMISSIVE, USEC_INFINITY);
619 return log_error_errno(fd, "Failed to acquire terminal: %m");
621 r = reset_terminal_fd(fd, true);
623 log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
625 r = rearrange_stdio(fd, fd, fd); /* This invalidates 'fd' both on success and on failure. */
627 return log_error_errno(r, "Failed to make terminal stdin/stdout/stderr: %m");
629 reset_terminal_feature_caches();
635 bool tty_is_vc(const char *tty) {
638 return vtnr_from_tty(tty) >= 0;
641 bool tty_is_console(const char *tty) {
644 return streq(skip_dev_prefix(tty), "console");
647 int vtnr_from_tty(const char *tty) {
652 tty = skip_dev_prefix(tty);
654 if (!startswith(tty, "tty") )
657 if (tty[3] < '0' || tty[3] > '9')
660 r = safe_atoi(tty+3, &i);
670 #if 0 /// UNNEEDED by elogind
671 int resolve_dev_console(char **ret) {
672 _cleanup_free_ char *active = NULL;
678 /* Resolve where /dev/console is pointing to, if /sys is actually ours (i.e. not read-only-mounted which is a
679 * sign for container setups) */
681 if (path_is_read_only_fs("/sys") > 0)
684 r = read_one_line_file("/sys/class/tty/console/active", &active);
688 /* If multiple log outputs are configured the last one is what /dev/console points to */
689 tty = strrchr(active, ' ');
695 if (streq(tty, "tty0")) {
696 active = mfree(active);
698 /* Get the active VC (e.g. tty1) */
699 r = read_one_line_file("/sys/class/tty/tty0/active", &active);
707 *ret = TAKE_PTR(active);
721 int get_kernel_consoles(char ***ret) {
722 _cleanup_strv_free_ char **l = NULL;
723 _cleanup_free_ char *line = NULL;
729 /* If /sys is mounted read-only this means we are running in some kind of container environment. In that
730 * case /sys would reflect the host system, not us, hence ignore the data we can read from it. */
731 if (path_is_read_only_fs("/sys") > 0)
734 r = read_one_line_file("/sys/class/tty/console/active", &line);
740 _cleanup_free_ char *tty = NULL;
743 r = extract_first_word(&p, &tty, NULL, 0);
749 if (streq(tty, "tty0")) {
751 r = read_one_line_file("/sys/class/tty/tty0/active", &tty);
756 path = strappend("/dev/", tty);
760 if (access(path, F_OK) < 0) {
761 log_debug_errno(errno, "Console device %s is not accessible, skipping: %m", path);
766 r = strv_consume(&l, path);
771 if (strv_isempty(l)) {
772 log_debug("No devices found for system console");
781 r = strv_extend(&l, "/dev/console");
790 bool tty_is_vc_resolve(const char *tty) {
791 _cleanup_free_ char *resolved = NULL;
795 tty = skip_dev_prefix(tty);
797 if (streq(tty, "console")) {
798 if (resolve_dev_console(&resolved) < 0)
804 return tty_is_vc(tty);
807 const char *default_term_for_tty(const char *tty) {
808 return tty && tty_is_vc_resolve(tty) ? "linux" : "vt220";
812 int fd_columns(int fd) {
813 struct winsize ws = {};
815 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
824 unsigned columns(void) {
828 if (cached_columns > 0)
829 return cached_columns;
832 e = getenv("COLUMNS");
834 (void) safe_atoi(e, &c);
837 c = fd_columns(STDOUT_FILENO);
843 return cached_columns;
846 int fd_lines(int fd) {
847 struct winsize ws = {};
849 if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
858 unsigned lines(void) {
862 if (cached_lines > 0)
868 (void) safe_atoi(e, &l);
871 l = fd_lines(STDOUT_FILENO);
880 /* intended to be used as a SIGWINCH sighandler */
881 #if 0 /// UNNEEDED by elogind
882 void columns_lines_cache_reset(int signum) {
888 void reset_terminal_feature_caches(void) {
892 cached_colors_enabled = -1;
893 cached_underline_enabled = -1;
899 /* We check both stdout and stderr, so that situations where pipes on the shell are used are reliably
900 * recognized, regardless if only the output or the errors are piped to some place. Since on_tty() is generally
901 * used to default to a safer, non-interactive, non-color mode of operation it's probably good to be defensive
902 * here, and check for both. Note that we don't check for STDIN_FILENO, because it should fine to use fancy
903 * terminal functionality when outputting stuff, even if the input is piped to us. */
905 if (cached_on_tty < 0)
907 isatty(STDOUT_FILENO) > 0 &&
908 isatty(STDERR_FILENO) > 0;
910 return cached_on_tty;
913 int getttyname_malloc(int fd, char **ret) {
923 r = ttyname_r(fd, path, sizeof(path));
927 c = strdup(skip_dev_prefix(path));
944 int getttyname_harder(int fd, char **r) {
948 k = getttyname_malloc(fd, &s);
952 if (streq(s, "tty")) {
954 return get_ctty(0, NULL, r);
961 int get_ctty_devnr(pid_t pid, dev_t *d) {
963 _cleanup_free_ char *line = NULL;
969 p = procfs_file_alloca(pid, "stat");
970 r = read_one_line_file(p, &line);
974 p = strrchr(line, ')');
989 if (major(ttynr) == 0 && minor(ttynr) == 0)
998 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
999 char fn[STRLEN("/dev/char/") + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
1000 _cleanup_free_ char *s = NULL;
1007 k = get_ctty_devnr(pid, &devnr);
1011 sprintf(fn, "/dev/char/%u:%u", major(devnr), minor(devnr));
1013 k = readlink_malloc(fn, &s);
1019 /* This is an ugly hack */
1020 if (major(devnr) == 136) {
1021 if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
1024 /* Probably something like the ptys which have no
1025 * symlink in /dev/char. Let's return something
1026 * vaguely useful. */
1033 if (startswith(s, "/dev/"))
1035 else if (startswith(s, "../"))
1052 #if 0 /// UNNEEDED by elogind
1053 int ptsname_malloc(int fd, char **ret) {
1066 if (ptsname_r(fd, c, l) == 0) {
1070 if (errno != ERANGE) {
1080 int ptsname_namespace(int pty, char **ret) {
1083 /* Like ptsname(), but doesn't assume that the path is
1084 * accessible in the local namespace. */
1086 r = ioctl(pty, TIOCGPTN, &no);
1093 if (asprintf(ret, "/dev/pts/%i", no) < 0)
1099 int openpt_in_namespace(pid_t pid, int flags) {
1100 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1101 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1107 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1111 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1114 r = safe_fork("(sd-openpt)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &child);
1120 pair[0] = safe_close(pair[0]);
1122 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1124 _exit(EXIT_FAILURE);
1126 master = posix_openpt(flags|O_NOCTTY|O_CLOEXEC);
1128 _exit(EXIT_FAILURE);
1130 if (unlockpt(master) < 0)
1131 _exit(EXIT_FAILURE);
1133 if (send_one_fd(pair[1], master, 0) < 0)
1134 _exit(EXIT_FAILURE);
1136 _exit(EXIT_SUCCESS);
1139 pair[1] = safe_close(pair[1]);
1141 r = wait_for_terminate_and_check("(sd-openpt)", child, 0);
1144 if (r != EXIT_SUCCESS)
1147 return receive_one_fd(pair[0], 0);
1150 int open_terminal_in_namespace(pid_t pid, const char *name, int mode) {
1151 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
1152 _cleanup_close_pair_ int pair[2] = { -1, -1 };
1156 r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
1160 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
1163 r = safe_fork("(sd-terminal)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &child);
1169 pair[0] = safe_close(pair[0]);
1171 r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
1173 _exit(EXIT_FAILURE);
1175 master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC);
1177 _exit(EXIT_FAILURE);
1179 if (send_one_fd(pair[1], master, 0) < 0)
1180 _exit(EXIT_FAILURE);
1182 _exit(EXIT_SUCCESS);
1185 pair[1] = safe_close(pair[1]);
1187 r = wait_for_terminate_and_check("(sd-terminal)", child, 0);
1190 if (r != EXIT_SUCCESS)
1193 return receive_one_fd(pair[0], 0);
1197 static bool getenv_terminal_is_dumb(void) {
1204 return streq(e, "dumb");
1207 bool terminal_is_dumb(void) {
1211 return getenv_terminal_is_dumb();
1214 bool colors_enabled(void) {
1216 /* Returns true if colors are considered supported on our stdout. For that we check $SYSTEMD_COLORS first
1217 * (which is the explicit way to turn colors on/off). If that didn't work we turn colors off unless we are on a
1218 * TTY. And if we are on a TTY we turn it off if $TERM is set to "dumb". There's one special tweak though: if
1219 * we are PID 1 then we do not check whether we are connected to a TTY, because we don't keep /dev/console open
1220 * continously due to fear of SAK, and hence things are a bit weird. */
1222 if (cached_colors_enabled < 0) {
1223 #if 0 /// elogind does not allow such forcing, and we are never init!
1226 val = getenv_bool("SYSTEMD_COLORS");
1228 cached_colors_enabled = val;
1229 else if (getpid_cached() == 1)
1230 /* PID1 outputs to the console without holding it open all the time */
1231 cached_colors_enabled = !getenv_terminal_is_dumb();
1234 cached_colors_enabled = !terminal_is_dumb();
1237 return cached_colors_enabled;
1240 #if 0 /// UNNEEDED by elogind
1241 bool dev_console_colors_enabled(void) {
1242 _cleanup_free_ char *s = NULL;
1245 /* Returns true if we assume that color is supported on /dev/console.
1247 * For that we first check if we explicitly got told to use colors or not, by checking $SYSTEMD_COLORS. If that
1248 * isn't set we check whether PID 1 has $TERM set, and if not, whether TERM is set on the kernel command
1249 * line. If we find $TERM set we assume color if it's not set to "dumb", similarly to how regular
1250 * colors_enabled() operates. */
1252 b = getenv_bool("SYSTEMD_COLORS");
1256 if (getenv_for_pid(1, "TERM", &s) <= 0)
1257 (void) proc_cmdline_get_key("TERM", 0, &s);
1259 return !streq_ptr(s, "dumb");
1263 bool underline_enabled(void) {
1265 if (cached_underline_enabled < 0) {
1267 /* The Linux console doesn't support underlining, turn it off, but only there. */
1269 if (colors_enabled())
1270 cached_underline_enabled = !streq_ptr(getenv("TERM"), "linux");
1272 cached_underline_enabled = false;
1275 return cached_underline_enabled;
1278 int vt_default_utf8(void) {
1279 _cleanup_free_ char *b = NULL;
1282 /* Read the default VT UTF8 setting from the kernel */
1284 r = read_one_line_file("/sys/module/vt/parameters/default_utf8", &b);
1288 return parse_boolean(b);
1291 int vt_reset_keyboard(int fd) {
1294 /* If we can't read the default, then default to unicode. It's 2017 after all. */
1295 kb = vt_default_utf8() != 0 ? K_UNICODE : K_XLATE;
1297 if (ioctl(fd, KDSKBMODE, kb) < 0)
1303 static bool urlify_enabled(void) {
1304 static int cached_urlify_enabled = -1;
1306 /* Unfortunately 'less' doesn't support links like this yet ðŸ˜, hence let's disable this as long as there's a
1307 * pager in effect. Let's drop this check as soon as less got fixed a and enough time passed so that it's safe
1308 * to assume that a link-enabled 'less' version has hit most installations. */
1310 if (cached_urlify_enabled < 0) {
1313 val = getenv_bool("SYSTEMD_URLIFY");
1315 cached_urlify_enabled = val;
1317 cached_urlify_enabled = colors_enabled() && !pager_have();
1320 return cached_urlify_enabled;
1323 int terminal_urlify(const char *url, const char *text, char **ret) {
1328 /* Takes an URL and a pretty string and formats it as clickable link for the terminal. See
1329 * https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda for details. */
1334 if (urlify_enabled())
1335 n = strjoin("\x1B]8;;", url, "\a", text, "\x1B]8;;\a");
1345 int terminal_urlify_path(const char *path, const char *text, char **ret) {
1346 _cleanup_free_ char *absolute = NULL;
1353 /* Much like terminal_urlify() above, but takes a file system path as input
1354 * and turns it into a proper file:// URL first. */
1362 if (!urlify_enabled()) {
1376 if (!path_is_absolute(path)) {
1377 r = path_make_absolute_cwd(path, &absolute);
1384 /* As suggested by https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda, let's include the local
1385 * hostname here. Note that we don't use gethostname_malloc() or gethostname_strict() since we are interested
1386 * in the raw string the kernel has set, whatever it may be, under the assumption that terminals are not overly
1387 * careful with validating the strings either. */
1389 url = strjoina("file://", u.nodename, path);
1391 return terminal_urlify(url, text, ret);
1394 static int cat_file(const char *filename, bool newline) {
1395 _cleanup_fclose_ FILE *f = NULL;
1396 _cleanup_free_ char *urlified = NULL;
1399 f = fopen(filename, "re");
1403 r = terminal_urlify_path(filename, NULL, &urlified);
1407 printf("%s%s# %s%s\n",
1408 newline ? "\n" : "",
1409 ansi_highlight_blue(),
1415 _cleanup_free_ char *line = NULL;
1417 r = read_line(f, LONG_LINE_MAX, &line);
1419 return log_error_errno(r, "Failed to read \"%s\": %m", filename);
1429 int cat_files(const char *file, char **dropins, CatFlags flags) {
1434 r = cat_file(file, false);
1435 if (r == -ENOENT && (flags & CAT_FLAGS_MAIN_FILE_OPTIONAL))
1436 printf("%s# config file %s not found%s\n",
1437 ansi_highlight_magenta(),
1441 return log_warning_errno(r, "Failed to cat %s: %m", file);
1444 STRV_FOREACH(path, dropins) {
1445 r = cat_file(*path, file || path != dropins);
1447 return log_warning_errno(r, "Failed to cat %s: %m", *path);
1453 void print_separator(void) {
1455 /* Outputs a separator line that resolves to whitespace when copied from the terminal. We do that by outputting
1456 * one line filled with spaces with ANSI underline set, followed by a second (empty) line. */
1458 if (underline_enabled()) {
1464 fputs_unlocked(ANSI_UNDERLINE, stdout);
1466 for (i = 0; i < c; i++)
1467 fputc_unlocked(' ', stdout);
1469 fputs_unlocked(ANSI_NORMAL "\n\n", stdout);
1470 funlockfile(stdout);
1472 fputs("\n\n", stdout);