src/basic/terminal-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "forward.h"
   5
   6 /* Erase characters until the end of the line */
   7 #define ANSI_ERASE_TO_END_OF_LINE "\x1B[K"
   8
   9 /* Erase characters until end of screen */
  10 #define ANSI_ERASE_TO_END_OF_SCREEN "\x1B[J"
  11
  12 /* Move cursor up one line */
  13 #define ANSI_REVERSE_LINEFEED "\x1BM"
  14
  15 /* Set cursor to top left corner and clear screen */
  16 #define ANSI_HOME_CLEAR "\x1B[H\x1B[2J"
  17
  18 /* Push/pop a window title off the stack of window titles */
  19 #define ANSI_WINDOW_TITLE_PUSH "\x1b[22;2t"
  20 #define ANSI_WINDOW_TITLE_POP "\x1b[23;2t"
  21
  22 /* The "device control string" ("DCS") start sequence */
  23 #define ANSI_DCS "\eP"
  24
  25 /* The "operating system command" ("OSC") start sequence */
  26 #define ANSI_OSC "\e]"
  27
  28 /* ANSI "string terminator" character ("ST"). Terminal emulators typically allow three different ones: 0x07,
  29  * 0x9c, and 0x1B 0x5C. We'll avoid 0x07 (BEL, aka ^G) since it might trigger unexpected TTY signal handling.
  30  * And we'll avoid 0x9c since that's also valid regular codepoint in UTF-8 and elsewhere, and creates
  31  * ambiguities. Because of that some terminal emulators explicitly choose not to support it. Hence we use
  32  * 0x1B 0x5c. */
  33 #define ANSI_ST "\e\\"
  34
  35 bool isatty_safe(int fd);
  36
  37 typedef enum TerminalResetFlags {
  38         TERMINAL_RESET_SWITCH_TO_TEXT = 1 << 0,
  39         TERMINAL_RESET_AVOID_ANSI_SEQ = 1 << 1,
  40         TERMINAL_RESET_FORCE_ANSI_SEQ = 1 << 2,
  41 } TerminalResetFlags;
  42
  43 int terminal_reset_defensive(int fd, TerminalResetFlags flags);
  44 int terminal_reset_defensive_locked(int fd, TerminalResetFlags flags);
  45
  46 int terminal_set_cursor_position(int fd, unsigned row, unsigned column);
  47
  48 int open_terminal(const char *name, int mode);
  49
  50 /* Flags for tweaking the way we become the controlling process of a terminal. */
  51 typedef enum AcquireTerminalFlags {
  52         /* Try to become the controlling process of the TTY. If we can't return -EPERM. */
  53         ACQUIRE_TERMINAL_TRY        = 0,
  54
  55         /* Tell the kernel to forcibly make us the controlling process of the TTY. Returns -EPERM if the kernel doesn't allow that. */
  56         ACQUIRE_TERMINAL_FORCE      = 1,
  57
  58         /* If we can't become the controlling process of the TTY right-away, then wait until we can. */
  59         ACQUIRE_TERMINAL_WAIT       = 2,
  60
  61         /* The combined mask of the above */
  62         _ACQUIRE_TERMINAL_MODE_MASK = ACQUIRE_TERMINAL_TRY | ACQUIRE_TERMINAL_FORCE | ACQUIRE_TERMINAL_WAIT,
  63
  64         /* Pick one of the above, and then OR this flag in, in order to request permissive behaviour, if we can't become controlling process then don't mind */
  65         ACQUIRE_TERMINAL_PERMISSIVE = 1 << 2,
  66
  67         /* Check for pending SIGTERM while waiting for inotify (SIGTERM must be blocked by caller) */
  68         ACQUIRE_TERMINAL_WATCH_SIGTERM = 1 << 3,
  69 } AcquireTerminalFlags;
  70
  71 int acquire_terminal(const char *name, AcquireTerminalFlags flags, usec_t timeout);
  72 int release_terminal(void);
  73
  74 int terminal_new_session(void);
  75 void terminal_detach_session(void);
  76
  77 int terminal_vhangup_fd(int fd);
  78 int terminal_vhangup(const char *tty);
  79
  80 int terminal_set_size_fd(int fd, const char *ident, unsigned rows, unsigned cols);
  81 int proc_cmdline_tty_size(const char *tty, unsigned *ret_rows, unsigned *ret_cols);
  82
  83 int chvt(int vt);
  84
  85 int read_one_char(FILE *f, char *ret, usec_t timeout, bool echo, bool *need_nl);
  86 int ask_char(char *ret, const char *replies, const char *text, ...) _printf_(3, 4);
  87
  88 typedef int (*GetCompletionsCallback)(const char *key, char ***ret_list, void *userdata);
  89 int ask_string_full(char **ret, GetCompletionsCallback cb, void *userdata, const char *text, ...) _printf_(4, 5);
  90 #define ask_string(ret, text, ...) ask_string_full(ret, NULL, NULL, text, ##__VA_ARGS__)
  91
  92 bool any_key_to_proceed(void);
  93 int show_menu(char **x, size_t n_columns, size_t column_width, unsigned ellipsize_percentage, const char *grey_prefix, bool with_numbers);
  94
  95 int vt_disallocate(const char *name);
  96
  97 int resolve_dev_console(char **ret);
  98 int get_kernel_consoles(char ***ret);
  99 bool tty_is_vc(const char *tty);
 100 bool tty_is_vc_resolve(const char *tty);
 101 bool tty_is_console(const char *tty) _pure_;
 102 int vtnr_from_tty(const char *tty);
 103
 104 void reset_dev_console_fd(int fd, bool switch_to_text);
 105 int lock_dev_console(void);
 106 int make_console_stdio(void);
 107
 108 int getenv_columns(void);
 109 int fd_columns(int fd);
 110 unsigned columns(void);
 111 int fd_lines(int fd);
 112 unsigned lines(void);
 113
 114 void columns_lines_cache_reset(int _unused_ signum);
 115 void reset_terminal_feature_caches(void);
 116
 117 bool on_tty(void);
 118 bool getenv_terminal_is_dumb(void);
 119 bool terminal_is_dumb(void);
 120
 121 bool dev_console_colors_enabled(void);
 122
 123 int get_ctty_devnr(pid_t pid, dev_t *ret);
 124 int get_ctty(pid_t, dev_t *ret_devnr, char **ret);
 125
 126 int getttyname_malloc(int fd, char **ret);
 127 int getttyname_harder(int fd, char **ret);
 128
 129 int ptsname_malloc(int fd, char **ret);
 130
 131 int openpt_allocate(int flags, char **ret_peer_path);
 132 int openpt_allocate_in_namespace(const PidRef *pidref, int flags, char **ret_peer_path);
 133
 134 int vt_restore(int fd);
 135 int vt_release(int fd, bool restore);
 136
 137 void get_log_colors(int priority, const char **on, const char **off, const char **highlight);
 138
 139 /* Assume TTY_MODE is defined in config.h. Also, this assumes there is a 'tty' group. */
 140 assert_cc((TTY_MODE & ~0666) == 0);
 141 assert_cc((TTY_MODE & 0711) == 0600);
 142
 143 void termios_disable_echo(struct termios *termios);
 144
 145 /* The $TERM value we use for terminals other than the Linux console */
 146 #define FALLBACK_TERM "vt220"
 147
 148 int get_default_background_color(double *ret_red, double *ret_green, double *ret_blue);
 149 int terminal_get_size_by_dsr(int input_fd, int output_fd, unsigned *ret_rows, unsigned *ret_columns);
 150 int terminal_fix_size(int input_fd, int output_fd);
 151
 152 int terminal_get_terminfo_by_dcs(int fd, char **ret_name);
 153 int have_terminfo_file(const char *name);
 154 int query_term_for_tty(const char *tty, char **ret_term);
 155
 156 int terminal_is_pty_fd(int fd);
 157
 158 int pty_open_peer(int fd, int mode);
 159
 160 static inline bool osc_char_is_valid(char c) {
 161         /* Checks whether the specified character is safe to be included inside an ANSI OSC sequence, as per
 162          * ECMA-48 5th edition, section 8.3.89 */
 163         return (unsigned char) c >= 32 && (unsigned char) c < 127;
 164 }
 165
 166 static inline bool vtnr_is_valid(unsigned n) {
 167         return n >= 1 && n <= 63;
 168 }