/* $OpenBSD: tty-features.c,v 1.43 2026/08/31 12:41:03 kirill Exp $ */

/*

 * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER

 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING

 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <sys/types.h>

#include <stdlib.h>

#include <string.h>

#if defined(HAVE_CURSES_H)

#include <curses.h>

#elif defined(HAVE_NCURSES_H)

#include <ncurses.h>

#endif

#include "tmux.h"

/*

 * Still hardcoded:

 * - default colours (under AX or op capabilities);

 * - AIX colours (under colors >= 16);

 * - alternate escape (if terminal is VT100-like).

 *

 * Also:

 * - DECFRA uses a flag instead of capabilities;

 * - UTF-8 is a separate flag on the client; needed for unattached clients.

 */

/* A named terminal feature. */

struct tty_feature {

  const char    *name;

  const char *const *capabilities;

  int      flags;

};

/* Terminal has xterm(1) title setting. */

static const char *const tty_feature_title_capabilities[] = {

  "tsl=\\E]0;", /* should be using TS really */

  "fsl=\\a",

  NULL

};

static const struct tty_feature tty_feature_title = {

  "title",

  tty_feature_title_capabilities,

  0

};

/* Terminal has OSC 7 working directory. */

static const char *const tty_feature_osc7_capabilities[] = {

  "Swd=\\E]7;",

  "fsl=\\a",

  NULL

};

static const struct tty_feature tty_feature_osc7 = {

  "osc7",

  tty_feature_osc7_capabilities,

  0

};

/* Terminal has mouse support. */

static const char *const tty_feature_mouse_capabilities[] = {

  "kmous=\\E[M",

  NULL

};

static const struct tty_feature tty_feature_mouse = {

  "mouse",

  tty_feature_mouse_capabilities,

  0

};

/* Terminal can set the clipboard with OSC 52. */

static const char *const tty_feature_clipboard_capabilities[] = {

  "Ms=\\E]52;%p1%s;%p2%s\\a",

  NULL

};

static const struct tty_feature tty_feature_clipboard = {

  "clipboard",

  tty_feature_clipboard_capabilities,

  0

};

/* Terminal supports OSC 8 hyperlinks. */

static const char *tty_feature_hyperlinks_capabilities[] = {

#if defined (__OpenBSD__) || (defined(NCURSES_VERSION_MAJOR) && \

  (NCURSES_VERSION_MAJOR > 5 || \

  (NCURSES_VERSION_MAJOR == 5 && NCURSES_VERSION_MINOR > 8)))

  "Hls=\\E]8;%?%p1%l%tid=%p1%s%;;%p2%s\\E\\\\",

#endif

  NULL

};

static const struct tty_feature tty_feature_hyperlinks = {

  "hyperlinks",

  tty_feature_hyperlinks_capabilities,

  0

};

/*

 * Terminal supports RGB colour. This replaces setab and setaf also since

 * terminals with RGB have versions that do not allow setting colours from the

 * 256 palette.

 */

static const char *const tty_feature_rgb_capabilities[] = {

  "AX",

  "setrgbf=\\E[38;2;%p1%d;%p2%d;%p3%dm",

  "setrgbb=\\E[48;2;%p1%d;%p2%d;%p3%dm",

  "setab=\\E[%?%p1%{8}%<%t4%p1%d%e%p1%{16}%<%t10%p1%{8}%-%d%e48;5;%p1%d%;m",

  "setaf=\\E[%?%p1%{8}%<%t3%p1%d%e%p1%{16}%<%t9%p1%{8}%-%d%e38;5;%p1%d%;m",

  NULL

};

static const struct tty_feature tty_feature_rgb = {

  "RGB",

  tty_feature_rgb_capabilities,

  TERM_256COLOURS|TERM_RGBCOLOURS

};

/* Terminal supports 256 colours. */

static const char *const tty_feature_256_capabilities[] = {

  "AX",

  "setab=\\E[%?%p1%{8}%<%t4%p1%d%e%p1%{16}%<%t10%p1%{8}%-%d%e48;5;%p1%d%;m",

  "setaf=\\E[%?%p1%{8}%<%t3%p1%d%e%p1%{16}%<%t9%p1%{8}%-%d%e38;5;%p1%d%;m",

  NULL

};

static const struct tty_feature tty_feature_256 = {

  "256",

  tty_feature_256_capabilities,

  TERM_256COLOURS

};

/* Terminal supports overline. */

static const char *const tty_feature_overline_capabilities[] = {

  "Smol=\\E[53m",

  NULL

};

static const struct tty_feature tty_feature_overline = {

  "overline",

  tty_feature_overline_capabilities,

  0

};

/* Terminal supports underscore styles. */

static const char *const tty_feature_usstyle_capabilities[] = {

  "Smulx=\\E[4::%p1%dm",

  "Setulc=\\E[58::2::%p1%{65536}%/%d::%p1%{256}%/%{255}%&%d::%p1%{255}%&%d%;m",

  "Setulc1=\\E[58::5::%p1%dm",

  "ol=\\E[59m",

  NULL

};

static const struct tty_feature tty_feature_usstyle = {

  "usstyle",

  tty_feature_usstyle_capabilities,

  0

};

/* Terminal supports bracketed paste. */

static const char *const tty_feature_bpaste_capabilities[] = {

  "Enbp=\\E[?2004h",

  "Dsbp=\\E[?2004l",

  NULL

};

static const struct tty_feature tty_feature_bpaste = {

  "bpaste",

  tty_feature_bpaste_capabilities,

  0

};

/* Terminal supports focus reporting. */

static const char *const tty_feature_focus_capabilities[] = {

  "Enfcs=\\E[?1004h",

  "Dsfcs=\\E[?1004l",

  NULL

};

static const struct tty_feature tty_feature_focus = {

  "focus",

  tty_feature_focus_capabilities,

  0

};

/* Terminal supports cursor styles. */

static const char *const tty_feature_cstyle_capabilities[] = {

  "Ss=\\E[%p1%d q",

  "Se=\\E[2 q",

  NULL

};

static const struct tty_feature tty_feature_cstyle = {

  "cstyle",

  tty_feature_cstyle_capabilities,

  0

};

/* Terminal supports cursor colours. */

static const char *const tty_feature_ccolour_capabilities[] = {

  "Cs=\\E]12;%p1%s\\a",

  "Cr=\\E]112\\a",

  NULL

};

static const struct tty_feature tty_feature_ccolour = {

  "ccolour",

  tty_feature_ccolour_capabilities,

  0

};

/* Terminal supports strikethrough. */

static const char *const tty_feature_strikethrough_capabilities[] = {

  "smxx=\\E[9m",

  NULL

};

static const struct tty_feature tty_feature_strikethrough = {

  "strikethrough",

  tty_feature_strikethrough_capabilities,

  0

};

/* Terminal supports synchronized updates. */

static const char *const tty_feature_sync_capabilities[] = {

  "Sync=\\E[?2026%?%p1%{1}%-%tl%eh%;",

  NULL

};

static const struct tty_feature tty_feature_sync = {

  "sync",

  tty_feature_sync_capabilities,

  0

};

/* Terminal supports extended keys. */

static const char *const tty_feature_extkeys_capabilities[] = {

  "Eneks=\\E[>4;2m",

  "Dseks=\\E[>4m",

  NULL

};

static const struct tty_feature tty_feature_extkeys = {

  "extkeys",

  tty_feature_extkeys_capabilities,

  0

};

/* Terminal supports DECSLRM margins. */

static const char *const tty_feature_margins_capabilities[] = {

  "Enmg=\\E[?69h",

  "Dsmg=\\E[?69l",

  "Clmg=\\E[s",

  "Cmg=\\E[%i%p1%d;%p2%ds",

  NULL

};

static const struct tty_feature tty_feature_margins = {

  "margins",

  tty_feature_margins_capabilities,

  TERM_DECSLRM

};

/* Terminal supports DECFRA rectangle fill. */

static const char *const tty_feature_rectfill_capabilities[] = {

  "Rect",

  NULL

};

static const struct tty_feature tty_feature_rectfill = {

  "rectfill",

  tty_feature_rectfill_capabilities,

  TERM_DECFRA

};

/* Use builtin function keys only. */

static const char *const tty_feature_ignorefkeys_capabilities[] = {

  "kf0@",

  "kf1@",

  "kf2@",

  "kf3@",

  "kf4@",

  "kf5@",

  "kf6@",

  "kf7@",

  "kf8@",

  "kf9@",

  "kf10@",

  "kf11@",

  "kf12@",

  "kf13@",

  "kf14@",

  "kf15@",

  "kf16@",

  "kf17@",

  "kf18@",

  "kf19@",

  "kf20@",

  "kf21@",

  "kf22@",

  "kf23@",

  "kf24@",

  "kf25@",

  "kf26@",

  "kf27@",

  "kf28@",

  "kf29@",

  "kf30@",

  "kf31@",

  "kf32@",

  "kf33@",

  "kf34@",

  "kf35@",

  "kf36@",

  "kf37@",

  "kf38@",

  "kf39@",

  "kf40@",

  "kf41@",

  "kf42@",

  "kf43@",

  "kf44@",

  "kf45@",

  "kf46@",

  "kf47@",

  "kf48@",

  "kf49@",

  "kf50@",

  "kf51@",

  "kf52@",

  "kf53@",

  "kf54@",

  "kf55@",

  "kf56@",

  "kf57@",

  "kf58@",

  "kf59@",

  "kf60@",

  "kf61@",

  "kf62@",

  "kf63@",

  NULL

};

static const struct tty_feature tty_feature_ignorefkeys = {

  "ignorefkeys",

  tty_feature_ignorefkeys_capabilities,

  0

};

/* Terminal has sixel capability. */

static const char *const tty_feature_sixel_capabilities[] = {

  "Sxl",

  NULL

};

static const struct tty_feature tty_feature_sixel = {

  "sixel",

  tty_feature_sixel_capabilities,

  TERM_SIXEL

};

/* Terminal supports the OSC 9;4 progress bar. */

static const char *const tty_feature_progressbar_capabilities[] = {

  "Spb=\\E]9;4;%p1%d;%p2%d\\E\\\\",

  NULL

};

static const struct tty_feature tty_feature_progressbar = {

  "progressbar",

  tty_feature_progressbar_capabilities,

  0

};

/* Terminal supports UTF-8. */

static const struct tty_feature tty_feature_utf8 = {

  "utf8",

  NULL,

  0

};

/* Available terminal features. */

static const struct tty_feature *const tty_features[] = {

  &tty_feature_256,

  &tty_feature_bpaste,

  &tty_feature_ccolour,

  &tty_feature_clipboard,

  &tty_feature_hyperlinks,

  &tty_feature_cstyle,

  &tty_feature_extkeys,

  &tty_feature_focus,

  &tty_feature_ignorefkeys,

  &tty_feature_margins,

  &tty_feature_mouse,

  &tty_feature_osc7,

  &tty_feature_overline,

  &tty_feature_progressbar,

  &tty_feature_rectfill,

  &tty_feature_rgb,

  &tty_feature_sixel,

  &tty_feature_strikethrough,

  &tty_feature_sync,

  &tty_feature_title,

  &tty_feature_usstyle,

  &tty_feature_utf8

};

/* Parse features for client. */

void

tty_parse_client_features(struct client *c, const char *s, const char *sep)

{

  tty_parse_features(s, sep, &c->term_features, &c->term_nofeatures);

}

/* Parse features list. */

void

tty_parse_features(const char *s, const char *sep, int *enabled, int *disabled)

{

  const struct tty_feature   *tf;

  char         *next, *loop, *copy;

  u_int         i;

  int         remove;

  log_debug("adding terminal features %s", s);

  loop = copy = xstrdup(s);

  while ((next = strsep(&loop, sep)) != NULL) {

    remove = (*next != '\0' && next[strlen(next) - 1] == '@');

    if (remove)

      next[strlen(next) - 1] = '\0';

    for (i = 0; i < nitems(tty_features); i++) {

      tf = tty_features[i];

      if (strcasecmp(tf->name, next) == 0)

        break;

    }

    if (i == nitems(tty_features)) {

      log_debug("unknown terminal feature: %s", next);

      break;

    }

    if (remove) {

      log_debug("removing terminal feature: %s", tf->name);

      *enabled &= ~(1 << i);

      if (disabled != NULL)

        *disabled |= 1 << i;

      continue;

    }

    if (disabled != NULL && *disabled & (1 << i))

      continue;

    if (~(*enabled) & (1 << i)) {

      log_debug("adding terminal feature: %s", tf->name);

      (*enabled) |= (1 << i);

    }

  }

  free(copy);

}

/* Get features as string. */

const char *

tty_get_features(int feat)

{

  const struct tty_feature  *tf;

  static char      s[512];

  u_int        i;

  *s = '\0';

  for (i = 0; i < nitems(tty_features); i++) {

    if (~feat & (1 << i))

      continue;

    tf = tty_features[i];

    strlcat(s, tf->name, sizeof s);

    strlcat(s, ",", sizeof s);

  }

  if (*s != '\0')

    s[strlen(s) - 1] = '\0';

  return (s);

}

/* Check if feature is present. */

int

tty_feature_present(struct tty_term *term, const char *name)

{

  const struct tty_feature  *tf = NULL;

  const char *const   *capability;

  u_int        i;

  char        *copy;

  if (strcmp(name, "utf8") == 0)

    return ((term->tty->client->flags & CLIENT_UTF8) != 0);

  for (i = 0; i < nitems(tty_features); i++) {

    tf = tty_features[i];

    if (strcmp(tf->name, name) == 0) {

      if (term->applied_features & (1 << i))

        return (1);

      break;

    }

  }

  /*

   * We don't just have the feature flag set. Check if the capabilities

   * supported by the client are actual set instead.

   */

  if (tf == NULL || tf->capabilities == NULL ||

      strcmp(name, "ignorefkeys") == 0)

    return (0);

  if (tf->flags != 0 && (term->flags & tf->flags) != tf->flags)

    return (0);

  capability = tf->capabilities;

  while (*capability != NULL) {

    copy = xstrdup(*capability);

    copy[strcspn(copy, "=")] = '\0';

    if (!tty_term_has_name(term, copy)) {

      free(copy);

      return (0);

    }

    free(copy);

    capability++;

  }

  return (1);

}

/* Apply featurs to terminal. */

int

tty_apply_features(struct tty_term *term)

{

  struct client     *c = term->tty->client;

  const struct tty_feature  *tf;

  const char *const   *capability;

  int        feat;

  u_int        i;

  feat = (c->term_features & ~c->term_nofeatures);

  if (feat == 0)

    return (0);

  log_debug("applying terminal features: %s", tty_get_features(feat));

  for (i = 0; i < nitems(tty_features); i++) {

    if ((term->applied_features & (1 << i)) || (~feat & (1 << i)))

      continue;

    tf = tty_features[i];

    log_debug("applying terminal feature: %s", tf->name);

    if (tf->capabilities != NULL) {

      capability = tf->capabilities;

      while (*capability != NULL) {

        log_debug("adding capability: %s", *capability);

        tty_term_apply(term, *capability, 1);

        capability++;

      }

    }

    term->flags |= tf->flags;

    if (tf == &tty_feature_utf8)

      c->flags |= CLIENT_UTF8;

  }

  if ((term->applied_features|feat) == term->applied_features)

    return (0);

  term->applied_features |= feat;

  return (1);

}

/* Add default features for a terminal identified by name and version. */

void

tty_default_features(struct client *c, const char *name, u_int version)

{

  static const struct {

    const char  *name;

    u_int    version;

    const char  *features;

  } table[] = {

#define TTY_FEATURES_BASE_MODERN_XTERM \

  "256,RGB,bpaste,clipboard,mouse,strikethrough,title"

    { .name = "mintty",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "margins,"

            "overline,"

            "usstyle"

    },

    { .name = "tmux",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "focus,"

            "overline,"

            "usstyle,"

            "hyperlinks,"

              "progressbar"

    },

    { .name = "rxvt-unicode",

      .features = "256,"

            "bpaste,"

            "ccolour,"

            "cstyle,"

            "mouse,"

            "title,"

            "ignorefkeys"

    },

    { .name = "iTerm2",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "cstyle,"

            "extkeys,"

            "margins,"

            "usstyle,"

            "sync,"

            "osc7,"

            "hyperlinks,"

              "progressbar"

    },

    { .name = "foot",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "usstyle,"

            "sync,"

            "osc7,"

            "hyperlinks"

    },

    { .name = "WezTerm",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "focus,"

              "hyperlinks,"

            "usstyle"

    },

    { .name = "ghostty",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "focus,"

            "overline,"

            "hyperlinks,"

            "osc7,"

            "sync,"

            "usstyle,"

            "progressbar"

    },

    { .name = "Rio",

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "focus,"

            "overline,"

            "hyperlinks,"

            "osc7,"

            "sync,"

            "usstyle,"

            "progressbar"

    },

    { .name = "XTerm",

      /*

       * xterm also supports DECSLRM and DECFRA, but they can be

       * disabled so not set it here - they will be added if

       * secondary DA shows VT420.

       */

      .features = TTY_FEATURES_BASE_MODERN_XTERM ","

            "ccolour,"

            "cstyle,"

            "extkeys,"

            "focus"

    }

  };

  u_int i;

  for (i = 0; i < nitems(table); i++) {

    if (strcmp(table[i].name, name) != 0)

      continue;

    if (version != 0 && version < table[i].version)

      continue;

    tty_parse_client_features(c, table[i].features, ",");

  }

}