1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2010 Lennart Poettering
12 #include <linux/tiocl.h>
20 #include <sys/inotify.h>
21 #include <sys/ioctl.h>
22 #include <sys/socket.h>
23 #include <sys/sysmacros.h>
25 #include <sys/types.h>
26 #include <sys/utsname.h>
30 #include "alloc-util.h"
41 #include "parse-util.h"
42 #include "path-util.h"
43 #include "proc-cmdline.h"
44 #include "process-util.h"
45 #include "socket-util.h"
46 #include "stat-util.h"
47 #include "string-util.h"
49 #include "terminal-util.h"
50 #include "time-util.h"
53 static volatile unsigned cached_columns
= 0;
54 static volatile unsigned cached_lines
= 0;
56 static volatile int cached_on_tty
= -1;
57 static volatile int cached_colors_enabled
= -1;
58 static volatile int cached_underline_enabled
= -1;
61 _cleanup_close_
int fd
;
63 /* Switch to the specified vt number. If the VT is specified <= 0 switch to the VT the kernel log messages go,
64 * if that's configured. */
66 fd
= open_terminal("/dev/tty0", O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
72 TIOCL_GETKMSGREDIRECT
,
76 if (ioctl(fd
, TIOCLINUX
, tiocl
) < 0)
79 vt
= tiocl
[0] <= 0 ? 1 : tiocl
[0];
82 if (ioctl(fd
, VT_ACTIVATE
, vt
) < 0)
88 int read_one_char(FILE *f
, char *ret
, usec_t t
, bool *need_nl
) {
89 struct termios old_termios
, new_termios
;
90 char c
, line
[LINE_MAX
];
95 if (tcgetattr(fileno(f
), &old_termios
) >= 0) {
96 new_termios
= old_termios
;
98 new_termios
.c_lflag
&= ~ICANON
;
99 new_termios
.c_cc
[VMIN
] = 1;
100 new_termios
.c_cc
[VTIME
] = 0;
102 if (tcsetattr(fileno(f
), TCSADRAIN
, &new_termios
) >= 0) {
105 if (t
!= USEC_INFINITY
) {
106 if (fd_wait_for_event(fileno(f
), POLLIN
, t
) <= 0) {
107 tcsetattr(fileno(f
), TCSADRAIN
, &old_termios
);
112 k
= fread(&c
, 1, 1, f
);
114 tcsetattr(fileno(f
), TCSADRAIN
, &old_termios
);
120 *need_nl
= c
!= '\n';
127 if (t
!= USEC_INFINITY
) {
128 if (fd_wait_for_event(fileno(f
), POLLIN
, t
) <= 0)
133 if (!fgets(line
, sizeof(line
), f
))
134 return errno
> 0 ? -errno
: -EIO
;
138 if (strlen(line
) != 1)
148 #define DEFAULT_ASK_REFRESH_USEC (2*USEC_PER_SEC)
150 int ask_char(char *ret
, const char *replies
, const char *fmt
, ...) {
162 if (colors_enabled())
163 fputs(ANSI_HIGHLIGHT
, stdout
);
171 if (colors_enabled())
172 fputs(ANSI_NORMAL
, stdout
);
176 r
= read_one_char(stdin
, &c
, DEFAULT_ASK_REFRESH_USEC
, &need_nl
);
183 puts("Bad input, please try again.");
194 if (strchr(replies
, c
)) {
199 puts("Read unexpected character, please try again.");
203 int ask_string(char **ret
, const char *text
, ...) {
211 if (colors_enabled())
212 fputs(ANSI_HIGHLIGHT
, stdout
);
218 if (colors_enabled())
219 fputs(ANSI_NORMAL
, stdout
);
224 if (!fgets(line
, sizeof(line
), stdin
))
225 return errno
> 0 ? -errno
: -EIO
;
227 if (!endswith(line
, "\n"))
246 int reset_terminal_fd(int fd
, bool switch_to_text
) {
247 struct termios termios
;
250 /* Set terminal to some sane defaults */
254 /* We leave locked terminal attributes untouched, so that
255 * Plymouth may set whatever it wants to set, and we don't
256 * interfere with that. */
258 /* Disable exclusive mode, just in case */
259 (void) ioctl(fd
, TIOCNXCL
);
261 /* Switch to text mode */
263 (void) ioctl(fd
, KDSETMODE
, KD_TEXT
);
265 /* Set default keyboard mode */
266 (void) vt_reset_keyboard(fd
);
268 if (tcgetattr(fd
, &termios
) < 0) {
273 /* We only reset the stuff that matters to the software. How
274 * hardware is set up we don't touch assuming that somebody
275 * else will do that for us */
277 termios
.c_iflag
&= ~(IGNBRK
| BRKINT
| ISTRIP
| INLCR
| IGNCR
| IUCLC
);
278 termios
.c_iflag
|= ICRNL
| IMAXBEL
| IUTF8
;
279 termios
.c_oflag
|= ONLCR
;
280 termios
.c_cflag
|= CREAD
;
281 termios
.c_lflag
= ISIG
| ICANON
| IEXTEN
| ECHO
| ECHOE
| ECHOK
| ECHOCTL
| ECHOPRT
| ECHOKE
;
283 termios
.c_cc
[VINTR
] = 03; /* ^C */
284 termios
.c_cc
[VQUIT
] = 034; /* ^\ */
285 termios
.c_cc
[VERASE
] = 0177;
286 termios
.c_cc
[VKILL
] = 025; /* ^X */
287 termios
.c_cc
[VEOF
] = 04; /* ^D */
288 termios
.c_cc
[VSTART
] = 021; /* ^Q */
289 termios
.c_cc
[VSTOP
] = 023; /* ^S */
290 termios
.c_cc
[VSUSP
] = 032; /* ^Z */
291 termios
.c_cc
[VLNEXT
] = 026; /* ^V */
292 termios
.c_cc
[VWERASE
] = 027; /* ^W */
293 termios
.c_cc
[VREPRINT
] = 022; /* ^R */
294 termios
.c_cc
[VEOL
] = 0;
295 termios
.c_cc
[VEOL2
] = 0;
297 termios
.c_cc
[VTIME
] = 0;
298 termios
.c_cc
[VMIN
] = 1;
300 if (tcsetattr(fd
, TCSANOW
, &termios
) < 0)
304 /* Just in case, flush all crap out */
305 (void) tcflush(fd
, TCIOFLUSH
);
310 int reset_terminal(const char *name
) {
311 _cleanup_close_
int fd
= -1;
313 /* We open the terminal with O_NONBLOCK here, to ensure we
314 * don't block on carrier if this is a terminal with carrier
317 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
321 return reset_terminal_fd(fd
, true);
324 int open_terminal(const char *name
, int mode
) {
329 * If a TTY is in the process of being closed opening it might
330 * cause EIO. This is horribly awful, but unlikely to be
331 * changed in the kernel. Hence we work around this problem by
332 * retrying a couple of times.
334 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
341 fd
= open(name
, mode
, 0);
348 /* Max 1s in total */
352 usleep(50 * USEC_PER_MSEC
);
356 if (isatty(fd
) <= 0) {
364 int acquire_terminal(
366 AcquireTerminalFlags flags
,
369 _cleanup_close_
int notify
= -1, fd
= -1;
370 usec_t ts
= USEC_INFINITY
;
374 assert(IN_SET(flags
& ~ACQUIRE_TERMINAL_PERMISSIVE
, ACQUIRE_TERMINAL_TRY
, ACQUIRE_TERMINAL_FORCE
, ACQUIRE_TERMINAL_WAIT
));
376 /* We use inotify to be notified when the tty is closed. We create the watch before checking if we can actually
377 * acquire it, so that we don't lose any event.
379 * Note: strictly speaking this actually watches for the device being closed, it does *not* really watch
380 * whether a tty loses its controlling process. However, unless some rogue process uses TIOCNOTTY on /dev/tty
381 * *after* closing its tty otherwise this will not become a problem. As long as the administrator makes sure to
382 * not configure any service on the same tty as an untrusted user this should not be a problem. (Which they
383 * probably should not do anyway.) */
385 if ((flags
& ~ACQUIRE_TERMINAL_PERMISSIVE
) == ACQUIRE_TERMINAL_WAIT
) {
386 notify
= inotify_init1(IN_CLOEXEC
| (timeout
!= USEC_INFINITY
? IN_NONBLOCK
: 0));
390 wd
= inotify_add_watch(notify
, name
, IN_CLOSE
);
394 if (timeout
!= USEC_INFINITY
)
395 ts
= now(CLOCK_MONOTONIC
);
399 struct sigaction sa_old
, sa_new
= {
400 .sa_handler
= SIG_IGN
,
401 .sa_flags
= SA_RESTART
,
405 r
= flush_fd(notify
);
410 /* We pass here O_NOCTTY only so that we can check the return value TIOCSCTTY and have a reliable way
411 * to figure out if we successfully became the controlling process of the tty */
412 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
416 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed if we already own the tty. */
417 assert_se(sigaction(SIGHUP
, &sa_new
, &sa_old
) == 0);
419 /* First, try to get the tty */
420 r
= ioctl(fd
, TIOCSCTTY
,
421 (flags
& ~ACQUIRE_TERMINAL_PERMISSIVE
) == ACQUIRE_TERMINAL_FORCE
) < 0 ? -errno
: 0;
423 /* Reset signal handler to old value */
424 assert_se(sigaction(SIGHUP
, &sa_old
, NULL
) == 0);
426 /* Success? Exit the loop now! */
430 /* Any failure besides -EPERM? Fail, regardless of the mode. */
434 if (flags
& ACQUIRE_TERMINAL_PERMISSIVE
) /* If we are in permissive mode, then EPERM is fine, turn this
435 * into a success. Note that EPERM is also returned if we
436 * already are the owner of the TTY. */
439 if (flags
!= ACQUIRE_TERMINAL_WAIT
) /* If we are in TRY or FORCE mode, then propagate EPERM as EPERM */
446 union inotify_event_buffer buffer
;
447 struct inotify_event
*e
;
450 if (timeout
!= USEC_INFINITY
) {
453 assert(ts
!= USEC_INFINITY
);
455 n
= now(CLOCK_MONOTONIC
);
456 if (ts
+ timeout
< n
)
459 r
= fd_wait_for_event(notify
, POLLIN
, ts
+ timeout
- n
);
466 l
= read(notify
, &buffer
, sizeof(buffer
));
468 if (IN_SET(errno
, EINTR
, EAGAIN
))
474 FOREACH_INOTIFY_EVENT(e
, buffer
, l
) {
475 if (e
->mask
& IN_Q_OVERFLOW
) /* If we hit an inotify queue overflow, simply check if the terminal is up for grabs now. */
478 if (e
->wd
!= wd
|| !(e
->mask
& IN_CLOSE
)) /* Safety checks */
485 /* We close the tty fd here since if the old session ended our handle will be dead. It's important that
486 * we do this after sleeping, so that we don't enter an endless loop. */
493 int release_terminal(void) {
494 static const struct sigaction sa_new
= {
495 .sa_handler
= SIG_IGN
,
496 .sa_flags
= SA_RESTART
,
499 _cleanup_close_
int fd
= -1;
500 struct sigaction sa_old
;
503 fd
= open("/dev/tty", O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
507 /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
508 * by our own TIOCNOTTY */
509 assert_se(sigaction(SIGHUP
, &sa_new
, &sa_old
) == 0);
511 r
= ioctl(fd
, TIOCNOTTY
) < 0 ? -errno
: 0;
513 assert_se(sigaction(SIGHUP
, &sa_old
, NULL
) == 0);
518 int terminal_vhangup_fd(int fd
) {
521 if (ioctl(fd
, TIOCVHANGUP
) < 0)
527 int terminal_vhangup(const char *name
) {
528 _cleanup_close_
int fd
;
530 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
534 return terminal_vhangup_fd(fd
);
537 int vt_disallocate(const char *name
) {
538 _cleanup_close_
int fd
= -1;
543 /* Deallocate the VT if possible. If not possible
544 * (i.e. because it is the active one), at least clear it
545 * entirely (including the scrollback buffer) */
547 e
= path_startswith(name
, "/dev/");
551 if (!tty_is_vc(name
)) {
552 /* So this is not a VT. I guess we cannot deallocate
553 * it then. But let's at least clear the screen */
555 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
560 "\033[r" /* clear scrolling region */
561 "\033[H" /* move home */
562 "\033[2J", /* clear screen */
567 n
= startswith(e
, "tty");
571 r
= safe_atou(n
, &u
);
578 /* Try to deallocate */
579 fd
= open_terminal("/dev/tty0", O_RDWR
|O_NOCTTY
|O_CLOEXEC
|O_NONBLOCK
);
583 r
= ioctl(fd
, VT_DISALLOCATE
, u
);
592 /* Couldn't deallocate, so let's clear it fully with
594 fd
= open_terminal(name
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
599 "\033[r" /* clear scrolling region */
600 "\033[H" /* move home */
601 "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
606 int make_console_stdio(void) {
609 /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
611 fd
= acquire_terminal("/dev/console", ACQUIRE_TERMINAL_FORCE
|ACQUIRE_TERMINAL_PERMISSIVE
, USEC_INFINITY
);
613 return log_error_errno(fd
, "Failed to acquire terminal: %m");
615 r
= reset_terminal_fd(fd
, true);
617 log_warning_errno(r
, "Failed to reset terminal, ignoring: %m");
619 r
= rearrange_stdio(fd
, fd
, fd
); /* This invalidates 'fd' both on success and on failure. */
621 return log_error_errno(r
, "Failed to make terminal stdin/stdout/stderr: %m");
623 reset_terminal_feature_caches();
628 bool tty_is_vc(const char *tty
) {
631 return vtnr_from_tty(tty
) >= 0;
634 bool tty_is_console(const char *tty
) {
637 return streq(skip_dev_prefix(tty
), "console");
640 int vtnr_from_tty(const char *tty
) {
645 tty
= skip_dev_prefix(tty
);
647 if (!startswith(tty
, "tty") )
650 if (tty
[3] < '0' || tty
[3] > '9')
653 r
= safe_atoi(tty
+3, &i
);
663 int resolve_dev_console(char **ret
) {
664 _cleanup_free_
char *active
= NULL
;
670 /* Resolve where /dev/console is pointing to, if /sys is actually ours (i.e. not read-only-mounted which is a
671 * sign for container setups) */
673 if (path_is_read_only_fs("/sys") > 0)
676 r
= read_one_line_file("/sys/class/tty/console/active", &active
);
680 /* If multiple log outputs are configured the last one is what /dev/console points to */
681 tty
= strrchr(active
, ' ');
687 if (streq(tty
, "tty0")) {
688 active
= mfree(active
);
690 /* Get the active VC (e.g. tty1) */
691 r
= read_one_line_file("/sys/class/tty/tty0/active", &active
);
699 *ret
= TAKE_PTR(active
);
713 int get_kernel_consoles(char ***ret
) {
714 _cleanup_strv_free_
char **l
= NULL
;
715 _cleanup_free_
char *line
= NULL
;
721 /* If /sys is mounted read-only this means we are running in some kind of container environment. In that
722 * case /sys would reflect the host system, not us, hence ignore the data we can read from it. */
723 if (path_is_read_only_fs("/sys") > 0)
726 r
= read_one_line_file("/sys/class/tty/console/active", &line
);
732 _cleanup_free_
char *tty
= NULL
;
735 r
= extract_first_word(&p
, &tty
, NULL
, 0);
741 if (streq(tty
, "tty0")) {
743 r
= read_one_line_file("/sys/class/tty/tty0/active", &tty
);
748 path
= strappend("/dev/", tty
);
752 if (access(path
, F_OK
) < 0) {
753 log_debug_errno(errno
, "Console device %s is not accessible, skipping: %m", path
);
758 r
= strv_consume(&l
, path
);
763 if (strv_isempty(l
)) {
764 log_debug("No devices found for system console");
773 r
= strv_extend(&l
, "/dev/console");
782 bool tty_is_vc_resolve(const char *tty
) {
783 _cleanup_free_
char *resolved
= NULL
;
787 tty
= skip_dev_prefix(tty
);
789 if (streq(tty
, "console")) {
790 if (resolve_dev_console(&resolved
) < 0)
796 return tty_is_vc(tty
);
799 const char *default_term_for_tty(const char *tty
) {
800 return tty
&& tty_is_vc_resolve(tty
) ? "linux" : "vt220";
803 int fd_columns(int fd
) {
804 struct winsize ws
= {};
806 if (ioctl(fd
, TIOCGWINSZ
, &ws
) < 0)
815 unsigned columns(void) {
819 if (cached_columns
> 0)
820 return cached_columns
;
823 e
= getenv("COLUMNS");
825 (void) safe_atoi(e
, &c
);
828 c
= fd_columns(STDOUT_FILENO
);
834 return cached_columns
;
837 int fd_lines(int fd
) {
838 struct winsize ws
= {};
840 if (ioctl(fd
, TIOCGWINSZ
, &ws
) < 0)
849 unsigned lines(void) {
853 if (cached_lines
> 0)
859 (void) safe_atoi(e
, &l
);
862 l
= fd_lines(STDOUT_FILENO
);
871 /* intended to be used as a SIGWINCH sighandler */
872 void columns_lines_cache_reset(int signum
) {
877 void reset_terminal_feature_caches(void) {
881 cached_colors_enabled
= -1;
882 cached_underline_enabled
= -1;
887 if (cached_on_tty
< 0)
888 cached_on_tty
= isatty(STDOUT_FILENO
) > 0;
890 return cached_on_tty
;
893 int getttyname_malloc(int fd
, char **ret
) {
903 r
= ttyname_r(fd
, path
, sizeof(path
));
907 c
= strdup(skip_dev_prefix(path
));
924 int getttyname_harder(int fd
, char **r
) {
928 k
= getttyname_malloc(fd
, &s
);
932 if (streq(s
, "tty")) {
934 return get_ctty(0, NULL
, r
);
941 int get_ctty_devnr(pid_t pid
, dev_t
*d
) {
943 _cleanup_free_
char *line
= NULL
;
949 p
= procfs_file_alloca(pid
, "stat");
950 r
= read_one_line_file(p
, &line
);
954 p
= strrchr(line
, ')');
969 if (major(ttynr
) == 0 && minor(ttynr
) == 0)
978 int get_ctty(pid_t pid
, dev_t
*_devnr
, char **r
) {
979 char fn
[STRLEN("/dev/char/") + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b
= NULL
;
980 _cleanup_free_
char *s
= NULL
;
987 k
= get_ctty_devnr(pid
, &devnr
);
991 sprintf(fn
, "/dev/char/%u:%u", major(devnr
), minor(devnr
));
993 k
= readlink_malloc(fn
, &s
);
999 /* This is an ugly hack */
1000 if (major(devnr
) == 136) {
1001 if (asprintf(&b
, "pts/%u", minor(devnr
)) < 0)
1004 /* Probably something like the ptys which have no
1005 * symlink in /dev/char. Let's return something
1006 * vaguely useful. */
1013 if (startswith(s
, "/dev/"))
1015 else if (startswith(s
, "../"))
1032 int ptsname_malloc(int fd
, char **ret
) {
1045 if (ptsname_r(fd
, c
, l
) == 0) {
1049 if (errno
!= ERANGE
) {
1059 int ptsname_namespace(int pty
, char **ret
) {
1062 /* Like ptsname(), but doesn't assume that the path is
1063 * accessible in the local namespace. */
1065 r
= ioctl(pty
, TIOCGPTN
, &no
);
1072 if (asprintf(ret
, "/dev/pts/%i", no
) < 0)
1078 int openpt_in_namespace(pid_t pid
, int flags
) {
1079 _cleanup_close_
int pidnsfd
= -1, mntnsfd
= -1, usernsfd
= -1, rootfd
= -1;
1080 _cleanup_close_pair_
int pair
[2] = { -1, -1 };
1086 r
= namespace_open(pid
, &pidnsfd
, &mntnsfd
, NULL
, &usernsfd
, &rootfd
);
1090 if (socketpair(AF_UNIX
, SOCK_DGRAM
, 0, pair
) < 0)
1093 r
= safe_fork("(sd-openpt)", FORK_RESET_SIGNALS
|FORK_DEATHSIG
, &child
);
1099 pair
[0] = safe_close(pair
[0]);
1101 r
= namespace_enter(pidnsfd
, mntnsfd
, -1, usernsfd
, rootfd
);
1103 _exit(EXIT_FAILURE
);
1105 master
= posix_openpt(flags
|O_NOCTTY
|O_CLOEXEC
);
1107 _exit(EXIT_FAILURE
);
1109 if (unlockpt(master
) < 0)
1110 _exit(EXIT_FAILURE
);
1112 if (send_one_fd(pair
[1], master
, 0) < 0)
1113 _exit(EXIT_FAILURE
);
1115 _exit(EXIT_SUCCESS
);
1118 pair
[1] = safe_close(pair
[1]);
1120 r
= wait_for_terminate_and_check("(sd-openpt)", child
, 0);
1123 if (r
!= EXIT_SUCCESS
)
1126 return receive_one_fd(pair
[0], 0);
1129 int open_terminal_in_namespace(pid_t pid
, const char *name
, int mode
) {
1130 _cleanup_close_
int pidnsfd
= -1, mntnsfd
= -1, usernsfd
= -1, rootfd
= -1;
1131 _cleanup_close_pair_
int pair
[2] = { -1, -1 };
1135 r
= namespace_open(pid
, &pidnsfd
, &mntnsfd
, NULL
, &usernsfd
, &rootfd
);
1139 if (socketpair(AF_UNIX
, SOCK_DGRAM
, 0, pair
) < 0)
1142 r
= safe_fork("(sd-terminal)", FORK_RESET_SIGNALS
|FORK_DEATHSIG
, &child
);
1148 pair
[0] = safe_close(pair
[0]);
1150 r
= namespace_enter(pidnsfd
, mntnsfd
, -1, usernsfd
, rootfd
);
1152 _exit(EXIT_FAILURE
);
1154 master
= open_terminal(name
, mode
|O_NOCTTY
|O_CLOEXEC
);
1156 _exit(EXIT_FAILURE
);
1158 if (send_one_fd(pair
[1], master
, 0) < 0)
1159 _exit(EXIT_FAILURE
);
1161 _exit(EXIT_SUCCESS
);
1164 pair
[1] = safe_close(pair
[1]);
1166 r
= wait_for_terminate_and_check("(sd-terminal)", child
, 0);
1169 if (r
!= EXIT_SUCCESS
)
1172 return receive_one_fd(pair
[0], 0);
1175 static bool getenv_terminal_is_dumb(void) {
1182 return streq(e
, "dumb");
1185 bool terminal_is_dumb(void) {
1189 return getenv_terminal_is_dumb();
1192 bool colors_enabled(void) {
1194 /* Returns true if colors are considered supported on our stdout. For that we check $SYSTEMD_COLORS first
1195 * (which is the explicit way to turn colors on/off). If that didn't work we turn colors off unless we are on a
1196 * 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
1197 * we are PID 1 then we do not check whether we are connected to a TTY, because we don't keep /dev/console open
1198 * continously due to fear of SAK, and hence things are a bit weird. */
1200 if (cached_colors_enabled
< 0) {
1203 val
= getenv_bool("SYSTEMD_COLORS");
1205 cached_colors_enabled
= val
;
1206 else if (getpid_cached() == 1)
1207 /* PID1 outputs to the console without holding it open all the time */
1208 cached_colors_enabled
= !getenv_terminal_is_dumb();
1210 cached_colors_enabled
= !terminal_is_dumb();
1213 return cached_colors_enabled
;
1216 bool dev_console_colors_enabled(void) {
1217 _cleanup_free_
char *s
= NULL
;
1220 /* Returns true if we assume that color is supported on /dev/console.
1222 * For that we first check if we explicitly got told to use colors or not, by checking $SYSTEMD_COLORS. If that
1223 * isn't set we check whether PID 1 has $TERM set, and if not, whether TERM is set on the kernel command
1224 * line. If we find $TERM set we assume color if it's not set to "dumb", similarly to how regular
1225 * colors_enabled() operates. */
1227 b
= getenv_bool("SYSTEMD_COLORS");
1231 if (getenv_for_pid(1, "TERM", &s
) <= 0)
1232 (void) proc_cmdline_get_key("TERM", 0, &s
);
1234 return !streq_ptr(s
, "dumb");
1237 bool underline_enabled(void) {
1239 if (cached_underline_enabled
< 0) {
1241 /* The Linux console doesn't support underlining, turn it off, but only there. */
1243 if (colors_enabled())
1244 cached_underline_enabled
= !streq_ptr(getenv("TERM"), "linux");
1246 cached_underline_enabled
= false;
1249 return cached_underline_enabled
;
1252 int vt_default_utf8(void) {
1253 _cleanup_free_
char *b
= NULL
;
1256 /* Read the default VT UTF8 setting from the kernel */
1258 r
= read_one_line_file("/sys/module/vt/parameters/default_utf8", &b
);
1262 return parse_boolean(b
);
1265 int vt_reset_keyboard(int fd
) {
1268 /* If we can't read the default, then default to unicode. It's 2017 after all. */
1269 kb
= vt_default_utf8() != 0 ? K_UNICODE
: K_XLATE
;
1271 if (ioctl(fd
, KDSKBMODE
, kb
) < 0)
1277 static bool urlify_enabled(void) {
1278 static int cached_urlify_enabled
= -1;
1280 /* Unfortunately 'less' doesn't support links like this yet ðŸ˜, hence let's disable this as long as there's a
1281 * pager in effect. Let's drop this check as soon as less got fixed a and enough time passed so that it's safe
1282 * to assume that a link-enabled 'less' version has hit most installations. */
1284 if (cached_urlify_enabled
< 0) {
1287 val
= getenv_bool("SYSTEMD_URLIFY");
1289 cached_urlify_enabled
= val
;
1291 cached_urlify_enabled
= colors_enabled() && !pager_have();
1294 return cached_urlify_enabled
;
1297 int terminal_urlify(const char *url
, const char *text
, char **ret
) {
1302 /* Takes an URL and a pretty string and formats it as clickable link for the terminal. See
1303 * https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda for details. */
1308 if (urlify_enabled())
1309 n
= strjoin("\x1B]8;;", url
, "\a", text
, "\x1B]8;;\a");
1319 int terminal_urlify_path(const char *path
, const char *text
, char **ret
) {
1320 _cleanup_free_
char *absolute
= NULL
;
1327 /* Much like terminal_urlify() above, but takes a file system path as input
1328 * and turns it into a proper file:// URL first. */
1336 if (!urlify_enabled()) {
1350 if (!path_is_absolute(path
)) {
1351 r
= path_make_absolute_cwd(path
, &absolute
);
1358 /* As suggested by https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda, let's include the local
1359 * hostname here. Note that we don't use gethostname_malloc() or gethostname_strict() since we are interested
1360 * in the raw string the kernel has set, whatever it may be, under the assumption that terminals are not overly
1361 * careful with validating the strings either. */
1363 url
= strjoina("file://", u
.nodename
, path
);
1365 return terminal_urlify(url
, text
, ret
);
1368 static int cat_file(const char *filename
, bool newline
) {
1369 _cleanup_fclose_
FILE *f
= NULL
;
1372 f
= fopen(filename
, "re");
1376 printf("%s%s# %s%s\n",
1377 newline
? "\n" : "",
1378 ansi_highlight_blue(),
1384 _cleanup_free_
char *line
= NULL
;
1386 r
= read_line(f
, LONG_LINE_MAX
, &line
);
1388 return log_error_errno(r
, "Failed to read \"%s\": %m", filename
);
1398 int cat_files(const char *file
, char **dropins
, CatFlags flags
) {
1403 r
= cat_file(file
, false);
1404 if (r
== -ENOENT
&& (flags
& CAT_FLAGS_MAIN_FILE_OPTIONAL
))
1405 printf("%s# config file %s not found%s\n",
1406 ansi_highlight_magenta(),
1410 return log_warning_errno(r
, "Failed to cat %s: %m", file
);
1413 STRV_FOREACH(path
, dropins
) {
1414 r
= cat_file(*path
, file
|| path
!= dropins
);
1416 return log_warning_errno(r
, "Failed to cat %s: %m", *path
);