diff options
| -rw-r--r-- | doc/lispref/display.texi | 4 | ||||
| -rw-r--r-- | doc/misc/efaq.texi | 97 | ||||
| -rw-r--r-- | etc/PROBLEMS | 7 | ||||
| -rw-r--r-- | lisp/find-file.el | 36 | ||||
| -rw-r--r-- | lisp/info.el | 9 | ||||
| -rw-r--r-- | lisp/international/characters.el | 19 | ||||
| -rw-r--r-- | lisp/international/latin1-disp.el | 4 | ||||
| -rw-r--r-- | lisp/jit-lock.el | 7 | ||||
| -rw-r--r-- | lisp/term/fbterm.el | 27 | ||||
| -rw-r--r-- | src/window.c | 3 | ||||
| -rw-r--r-- | src/xdisp.c | 28 |
11 files changed, 205 insertions, 36 deletions
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi index db58cd14c63..69b752688ea 100644 --- a/doc/lispref/display.texi +++ b/doc/lispref/display.texi @@ -8554,6 +8554,7 @@ Display with @var{graphical} on graphical displays, and with must be one of the display methods described above. @end table +@vindex glyphless-char@r{ face} @noindent The @code{thin-space}, @code{empty-box}, @code{hex-code}, and @acronym{ASCII} string display methods are drawn with the @@ -8618,7 +8619,8 @@ codepoints (typically emojis). @item no-font Characters for which there is no suitable font, or which cannot be -encoded by the terminal's coding system. +encoded by the terminal's coding system, or those for which the +text-mode terminal has no glyphs. @end table @c FIXME: this can also be 'acronym', but that's not currently diff --git a/doc/misc/efaq.texi b/doc/misc/efaq.texi index a3459abd041..43fa0054346 100644 --- a/doc/misc/efaq.texi +++ b/doc/misc/efaq.texi @@ -1602,6 +1602,7 @@ is better to write ``Emacs and XEmacs.'' * Filling paragraphs with a single space:: * Escape sequences in shell output:: * Fullscreen mode on MS-Windows:: +* Emacs in a Linux console:: @end menu @node Setting up a customization file @@ -3031,6 +3032,102 @@ To compute the correct values for width and height, first maximize the Emacs frame and then evaluate @code{(frame-height)} and @code{(frame-width)} with @kbd{M-:}. +@node Emacs in a Linux console +@section How can I alleviate the limitations of the Linux console? +@cindex Console, Linux console, TTY, fbterm + +If possible, we recommend running Emacs inside @command{fbterm}, when +in a Linux console. This brings the Linux console on par with most +terminal emulators under X. To do this, install @command{fbterm}, for +example with the package manager of your GNU/Linux distribution, and +execute the command + +@example +$ fbterm +@end example + +This will create a sample configuration file @file{~/.fbtermrc} in +your home directory. Edit that file and change the options +@code{font-names} and @code{font-size} if necessary. For the former, +you can choose one or more of the lines in the output of the following +command, separated by commas: + +@example +$ fc-list :spacing=mono family | sed 's/ /\\ /g' +@end example + +You can now start Emacs inside @command{fbterm} with the command + +@example +$ fbterm -- env TERM=fbterm emacs +@end example + +In some versions of @command{fbterm}, setting @env{TERM} to +@samp{fbterm} can be omitted. To check whether it is needed, start +Emacs inside @command{fbterm} with the command + +@example +$ fbterm -- emacs +@end example + +@noindent +and type @kbd{M-x list-colors-display}. If only 8 colors are +displayed, it is necessary; if 256 colors are displayed, it isn't. + +You may want to add an alias for that command in your shell +configuration file. For example, if you use Bash, you can add the +following line to your @file{~/.bashrc} file: + +@example +alias emacs="fbterm -- env TERM=fbterm emacs" +@end example + +@noindent +or, if you use Emacs both in the Linux console and under X: + +@example +[[ "$(tty)" =~ "/dev/tty" ]] && alias emacs="fbterm -- env TERM=fbterm emacs" +@end example + +The @command{fbterm} terminal emulator may define a number of key +bindings for its own use, some of which conflict with those that Emacs +uses. Execute the following two commands as root to ensure that +@command{fbterm} does not define these key bindings: + +@example +# chmod a-s `which fbterm` +# setcap cap_sys_tty_config=-ep `which fbterm` +@end example + +If you use Emacs as root, the above is not enough however, because the +root user has all privileges. You can use the following command to +start Emacs inside @command{fbterm} as root while ensuring that +@command{fbterm} does not define any key bindings for its own use: + +@example +# capsh --drop=cap_sys_tty_config -- -c "fbterm -- env TERM=fbterm emacs" +@end example + +Again you may want to add a shortcut for that command in the shell +configuration file of the root user. In this case however, it is not +possible to use an alias, because the command line arguments passed to +Emacs need to be inserted in the string at the end of the command. A +wrapper script or a function can be used to do that. For example, if +you use Bash, you can add the following function in the root user +@file{~/.bashrc} file: + +@example +function emacs () +@{ + CMD="fbterm -- env TERM=fbterm emacs " + for ARG in "$@@" + do + CMD="$CMD '$ARG' " + done + capsh --drop=cap_sys_tty_config -- -c "$CMD" +@} +@end example + @c ------------------------------------------------------------ @node Bugs and problems @chapter Bugs and problems diff --git a/etc/PROBLEMS b/etc/PROBLEMS index 6624f747c87..ed2bc1ae051 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -2267,6 +2267,13 @@ term/xterm.el) for more details. *** Linux console problems with double-width characters +If possible, we recommend running Emacs inside fbterm, when in a Linux +console (see the node "Emacs in a Linux console" in the Emacs FAQ). +Most Unicode characters should then be displayed correctly. + +If that is not possible, the following may be useful to alleviate the +problem of displaying Unicode characters in a raw console. + The Linux console declares UTF-8 encoding, but supports only a limited number of Unicode characters, and can cause Emacs produce corrupted or garbled display with some unusual characters and sequences. Emacs 28 diff --git a/lisp/find-file.el b/lisp/find-file.el index 614ff420f25..646779fc919 100644 --- a/lisp/find-file.el +++ b/lisp/find-file.el @@ -193,18 +193,32 @@ The value could be an alist or a symbol whose value is an alist. Each element of the alist has the form (REGEXP (EXTENSION...)) -or - (REGEXP FUNCTION) where REGEXP is the regular expression matching a file's extension, -EXTENSIONs is the list of literal file-name extensions to search for, -and FUNCTION is a function of one argument, the current file's name, -that returns the list of extensions to search for. -The list of extensions should contain the most used extensions before the -others, since the search algorithm searches sequentially through each -directory specified in `ff-search-directories'. If a file is not found, -a new one is created with the first matching extension (`.cc' yields `.hh'). -This alist should be set by the major mode." +and EXTENSIONs is the list of literal file-name extensions to search +for. The list of extensions should contain the most used extensions +before the others, since the search algorithm searches sequentially +through each directory specified in `ff-search-directories'. + +Alist elements can also be of the form + + (REGEXP FUNCTION) + +where FUNCTION is a function of one argument, the current file's name, +that returns the list of possible names of the corresponding files, with +or without leading directories. Note the difference: FUNCTION returns +the list of file names, not their extensions. This is for the case when +REGEXP is not enough to determine the file name of the other file. + +If a file is not found, a new one is created with the first +matching extension or name (e.g., `.cc' yields `.hh'). + +This alist should be set by the major mode. + +Note: if an element of the alist names a FUNCTION as its cdr, that +function must return a non-nil list of file-names. It cannot +return nil, nor can it signal in any way a failure to find a suitable +list of file names." :type '(choice (repeat (list regexp (choice (repeat string) function))) symbol)) @@ -615,7 +629,7 @@ name of the first file found." (while (and suffixes (not found)) (setq filename (concat fname-stub this-suffix)) - (setq file (concat dir "/" filename)) + (setq file (expand-file-name filename dir)) (if (not ff-quiet-mode) (message "Finding %s..." file)) diff --git a/lisp/info.el b/lisp/info.el index fb4c3fd7829..1a58910c3af 100644 --- a/lisp/info.el +++ b/lisp/info.el @@ -4451,9 +4451,12 @@ Advanced commands: (setq buffer-read-only t) (setq Info-tag-table-marker (make-marker)) (unless (or (display-multi-font-p) - (coding-system-equal - (coding-system-base (terminal-coding-system)) - 'utf-8)) + (and (coding-system-equal + (coding-system-base (terminal-coding-system)) + 'utf-8) + ;; The Linux console has limited character + ;; repertoire even when its encoding is UTF-8. + (not (equal (tty-type) "linux")))) (dolist (elt info-symbols-and-replacements) (let ((ch (car elt)) (repl (cdr elt))) diff --git a/lisp/international/characters.el b/lisp/international/characters.el index d6e83c81e74..245ade54e18 100644 --- a/lisp/international/characters.el +++ b/lisp/international/characters.el @@ -1661,12 +1661,14 @@ GROUP must be one of these symbols: like U+2069 (PDI) and U+202B (RLE). `variation-selectors': Characters in the range U+FE00..U+FE0F and - U+E0100..U+E01EF, used for selecting alternate glyph - presentations, such as Emoji vs Text presentation, of - the preceding character(s). - `no-font': For GUI frames, characters for which no suitable - font is found; for text-mode frames, characters - that cannot be encoded by `terminal-coding-system'. + U+E0100..U+E01EF, used for choosing between + glyph variations, such as Emoji vs Text + presentation, of the preceding character(s). + `no-font': For GUI frames, characters for which no + suitable font is found; for text-mode frames, + characters that cannot be encoded by + `terminal-coding-system' or those for which + the terminal has no glyphs. METHOD must be one of these symbols: `zero-width': don't display. @@ -1680,7 +1682,10 @@ METHOD must be one of these symbols: Do not set its value directly from Lisp; the value takes effect only via a custom `:set' function (`update-glyphless-char-display'), which updates -`glyphless-char-display'." +`glyphless-char-display'. + +See also the `glyphless-char' face, which is used to display the +visual representation of these characters." :version "28.1" :type '(alist :key-type (symbol :tag "Character Group") :value-type (symbol :tag "Display Method")) diff --git a/lisp/international/latin1-disp.el b/lisp/international/latin1-disp.el index 4de1d6084fb..cb3b429957c 100644 --- a/lisp/international/latin1-disp.el +++ b/lisp/international/latin1-disp.el @@ -87,7 +87,7 @@ This option also treats some characters in the `mule-unicode-...' charsets if you don't have a Unicode font with which to display them. Setting this variable directly does not take effect; -use either \\[customize] or the function `latin1-display'." +use either \\[customize] or the command `latin1-display'." :group 'latin1-display :type 'boolean :require 'latin1-disp @@ -746,7 +746,7 @@ This uses the transliterations of the Lynx browser. The display isn't changed if the display can render Unicode characters. Setting this variable directly does not take effect; -use either \\[customize] or the function `latin1-display'." +use either \\[customize] or the command `latin1-display-ucs-per-lynx'." :group 'latin1-display :type 'boolean :require 'latin1-disp diff --git a/lisp/jit-lock.el b/lisp/jit-lock.el index be26ca55f0d..9543253cf24 100644 --- a/lisp/jit-lock.el +++ b/lisp/jit-lock.el @@ -45,9 +45,12 @@ Preserves the `buffer-modified-p' state of the current buffer." :group 'font-lock) (defcustom jit-lock-chunk-size 1500 - "Jit-lock fontifies chunks of at most this many characters at a time. + "Jit-lock asks to fontify chunks of at most this many characters at a time. -This variable controls both `display-time' and stealth fontification. +The actual size of the fontified chunk of text can be different, +depending on what the `fontification-functions' actually decide to do. + +This variable controls both display-time and stealth fontifications. The optimum value is a little over the typical number of buffer characters which fit in a typical window." diff --git a/lisp/term/fbterm.el b/lisp/term/fbterm.el new file mode 100644 index 00000000000..ad7150c1a1f --- /dev/null +++ b/lisp/term/fbterm.el @@ -0,0 +1,27 @@ +;;; fbterm.el -*- lexical-binding:t -*- + +;; Copyright (C) 2022 Free Software Foundation, Inc. + +;; Note that, in some versions of fbterm, the TERM environment +;; variable is set to "linux". When that's the case, the code below +;; will not be executed, and only 8 colors will be available. It is +;; therefore necessary, with these versions of fbterm, to set that +;; environment variable to "fbterm" to enable its 256 color mode +;; extension. See also the node "Emacs in a Linux console" of the +;; Emacs FAQ. + +(require 'term/xterm) + +(defun terminal-init-fbterm () + "Terminal initialization function for fbterm." + + ;; fbterm can't display underlines, even though its terminfo data + ;; says it can. + (tty-no-underline) + + ;; fbterm supports xterm's 256 color mode extension. + (xterm-register-default-colors xterm-standard-colors)) + +(provide 'term/fbterm) + +;;; fbterm.el ends here diff --git a/src/window.c b/src/window.c index 2bce4c9723d..12a212a85ac 100644 --- a/src/window.c +++ b/src/window.c @@ -8363,7 +8363,8 @@ on their symbols to be controlled by this variable. */); Vscroll_preserve_screen_position = Qnil; DEFVAR_LISP ("window-point-insertion-type", Vwindow_point_insertion_type, - doc: /* Type of marker to use for `window-point'. */); + doc: /* Insertion type of marker to use for `window-point'. +See `marker-insertion-type' for the meaning of the possible values. */); Vwindow_point_insertion_type = Qnil; DEFSYM (Qwindow_point_insertion_type, "window-point-insertion-type"); diff --git a/src/xdisp.c b/src/xdisp.c index 70f6936dd0b..2c9dc63a389 100644 --- a/src/xdisp.c +++ b/src/xdisp.c @@ -7842,7 +7842,13 @@ lookup_glyphless_char_display (int c, struct it *it) && CHAR_TABLE_EXTRA_SLOTS (XCHAR_TABLE (Vglyphless_char_display)) >= 1) { if (c >= 0) - glyphless_method = CHAR_TABLE_REF (Vglyphless_char_display, c); + { + glyphless_method = CHAR_TABLE_REF (Vglyphless_char_display, c); + if (CONSP (glyphless_method)) + glyphless_method = FRAME_WINDOW_P (it->f) + ? XCAR (glyphless_method) + : XCDR (glyphless_method); + } else glyphless_method = XCHAR_TABLE (Vglyphless_char_display)->extras[0]; @@ -31773,9 +31779,9 @@ gui_produce_glyphs (struct it *it) /* When no suitable font is found, display this character by the method specified in the first extra slot of Vglyphless_char_display. */ - Lisp_Object acronym = lookup_glyphless_char_display (-1, it); + Lisp_Object acronym = lookup_glyphless_char_display (-1, it); - eassert (it->what == IT_GLYPHLESS); + eassert (it->what == IT_GLYPHLESS); produce_glyphless_glyph (it, true, STRINGP (acronym) ? acronym : Qnil); goto done; @@ -37109,16 +37115,20 @@ Each element, if non-nil, should be one of the following: `empty-box': display as an empty box `thin-space': display as 1-pixel width space `zero-width': don't display +Any other value is interpreted as `empty-box'. An element may also be a cons cell (GRAPHICAL . TEXT), which specifies the display method for graphical terminals and text terminals respectively. GRAPHICAL and TEXT should each have one of the values listed above. -The char-table has one extra slot to control the display of a character for -which no font is found. This slot only takes effect on graphical terminals. -Its value should be an ASCII acronym string, `hex-code', `empty-box', or -`thin-space'. It could also be a cons cell of any two of these, to specify -separate values for graphical and text terminals. -The default is `empty-box'. +The char-table has one extra slot to control the display of characters +for which no font is found on graphical terminals, and characters that +cannot be displayed by text-mode terminals. Its value should be an +ASCII acronym string, `hex-code', `empty-box', or `thin-space'. It +could also be a cons cell of any two of these, to specify separate +values for graphical and text terminals. The default is `empty-box'. + +With the obvious exception of `zero-width', all the other representations +are displayed using the face `glyphless-char'. If a character has a non-nil entry in an active display table, the display table takes effect; in this case, Emacs does not consult |