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diff --git a/man4/console_codes.4 b/man4/console_codes.4 new file mode 100644 index 0000000..e2ac4e8 --- /dev/null +++ b/man4/console_codes.4 @@ -0,0 +1,810 @@ +'\" t +.\" Copyright (c) 1996 Andries Brouwer <aeb@cwi.nl>, Mon Oct 31 22:13:04 1996 +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.\" This is combined from many sources. +.\" For Linux, the definitive source is of course console.c. +.\" About vt100-like escape sequences in general there are +.\" the ISO 6429 and ISO 2022 norms, the descriptions of +.\" an actual vt100, and the xterm docs (ctlseqs.ms). +.\" Substantial portions of this text are derived from a write-up +.\" by Eric S. Raymond <esr@thyrsus.com>. +.\" +.\" Tiny correction, aeb, 961107. +.\" +.\" 2006-05-27, Several corrections - Thomas E. Dickey +.\" +.TH console_codes 4 2023-02-05 "Linux man-pages 6.05.01" +.SH NAME +console_codes \- Linux console escape and control sequences +.SH DESCRIPTION +The Linux console implements a large subset of the VT102 and ECMA-48/ISO +6429/ANSI X3.64 terminal controls, plus certain private-mode sequences +for changing the color palette, character-set mapping, and so on. +In the tabular descriptions below, the second column gives ECMA-48 or DEC +mnemonics (the latter if prefixed with DEC) for the given function. +Sequences without a mnemonic are neither ECMA-48 nor VT102. +.PP +After all the normal output processing has been done, and a +stream of characters arrives at the console driver for actual +printing, the first thing that happens is a translation from +the code used for processing to the code used for printing. +.PP +If the console is in UTF-8 mode, then the incoming bytes are +first assembled into 16-bit Unicode codes. +Otherwise, each byte is transformed according to the current mapping table +(which translates it to a Unicode value). +See the \fBCharacter Sets\fP section below for discussion. +.PP +In the normal case, the Unicode value is converted to a font index, +and this is stored in video memory, so that the corresponding glyph +(as found in video ROM) appears on the screen. +Note that the use of Unicode (and the design of the PC hardware) +allows us to use 512 different glyphs simultaneously. +.PP +If the current Unicode value is a control character, or we are +currently processing an escape sequence, the value will treated +specially. +Instead of being turned into a font index and rendered as +a glyph, it may trigger cursor movement or other control functions. +See the \fBLinux Console Controls\fP section below for discussion. +.PP +It is generally not good practice to hard-wire terminal controls into +programs. +Linux supports a +.BR terminfo (5) +database of terminal capabilities. +Rather than emitting console escape sequences by hand, you will almost +always want to use a terminfo-aware screen library or utility such as +.BR ncurses (3), +.BR tput (1), +or +.BR reset (1). +.SS Linux console controls +This section describes all the control characters and escape sequences +that invoke special functions (i.e., anything other than writing a +glyph at the current cursor location) on the Linux console. +.PP +.B "Control characters" +.PP +A character is a control character if (before transformation +according to the mapping table) it has one of the 14 codes +00 (NUL), 07 (BEL), 08 (BS), 09 (HT), 0a (LF), 0b (VT), +0c (FF), 0d (CR), 0e (SO), 0f (SI), 18 (CAN), 1a (SUB), +1b (ESC), 7f (DEL). +One can set a "display control characters" mode (see below), +and allow 07, 09, 0b, 18, 1a, 7f to be displayed as glyphs. +On the other hand, in UTF-8 mode all codes 00\[en]1f are regarded +as control characters, regardless of any "display control characters" +mode. +.PP +If we have a control character, it is acted upon immediately +and then discarded (even in the middle of an escape sequence) +and the escape sequence continues with the next character. +(However, ESC starts a new escape sequence, possibly aborting a previous +unfinished one, and CAN and SUB abort any escape sequence.) +The recognized control characters are BEL, BS, HT, LF, VT, FF, +CR, SO, SI, CAN, SUB, ESC, DEL, CSI. +They do what one would expect: +.TP +BEL (0x07, \fB\[ha]G\fP) +beeps; +.TP +BS (0x08, \fB\[ha]H\fP) +backspaces one column +(but not past the beginning of the line); +.TP +HT (0x09, \fB\[ha]I\fP) +goes to the next tab stop or to the end of the line +if there is no earlier tab stop; +.TP +LF (0x0A, \fB\[ha]J\fP) +.TQ +VT (0x0B, \fB\[ha]K\fP) +.TQ +FF (0x0C, \fB\[ha]L\fP) +all give a linefeed, +and if LF/NL (new-line mode) is set also a carriage return; +.TP +CR (0x0D, \fB\[ha]M\fP) +gives a carriage return; +.TP +SO (0x0E, \fB\[ha]N\fP) +activates the G1 character set; +.TP +SI (0x0F, \fB\[ha]O\fP) +activates the G0 character set; +.TP +CAN (0x18, \fB\[ha]X\fP) +.TQ +SUB (0x1A, \fB\[ha]Z\fP) +abort escape sequences; +.TP +ESC (0x1B, \fB\[ha][\fP) +starts an escape sequence; +.TP +DEL (0x7F) +is ignored; +.TP +CSI (0x9B) +is equivalent to ESC [. +.PP +.B "ESC- but not CSI-sequences" +.ad l +.TS +l l lx. +ESC c RIS Reset. +ESC D IND Linefeed. +ESC E NEL Newline. +ESC H HTS Set tab stop at current column. +ESC M RI Reverse linefeed. +ESC Z DECID T{ +DEC private identification. The kernel +returns the string ESC [ ? 6 c, claiming +that it is a VT102. +T} +ESC 7 DECSC T{ +Save current state (cursor coordinates, +attributes, character sets pointed at by G0, G1). +T} +ESC 8 DECRC T{ +Restore state most recently saved by ESC 7. +T} +ESC % Start sequence selecting character set +ESC % @ \0\0\0Select default (ISO 646 / ISO 8859-1) +ESC % G \0\0\0Select UTF-8 +ESC % 8 \0\0\0Select UTF-8 (obsolete) +ESC # 8 DECALN T{ +DEC screen alignment test \- fill screen with E's. +T} +ESC ( T{ +Start sequence defining G0 character set +(followed by one of B, 0, U, K, as below) +T} +ESC ( B T{ +Select default (ISO 8859-1 mapping). +T} +ESC ( 0 T{ +Select VT100 graphics mapping. +T} +ESC ( U T{ +Select null mapping \- straight to character ROM. +T} +ESC ( K T{ +Select user mapping \- the map that is loaded by the utility \fBmapscrn\fP(8). +T} +ESC ) T{ +Start sequence defining G1 (followed by one of B, 0, U, K, as above). +T} +ESC > DECPNM Set numeric keypad mode +ESC = DECPAM Set application keypad mode +ESC ] OSC T{ +Operating System Command prefix. +T} +ESC ] R Reset palette. +ESC ] P T{ +Set palette, with parameter given in 7 hexadecimal digits \fInrrggbb\fP after +the final P. Here \fIn\fP is the color (0\[en]15), and \fIrrggbb\fP indicates +the red/green/blue values (0\[en]255). +T} +.TE +.ad +.PP +.B "ECMA-48 CSI sequences" +.PP +CSI (or ESC [) is followed by a sequence of parameters, +at most NPAR (16), that are decimal numbers separated by +semicolons. +An empty or absent parameter is taken to be 0. +The sequence of parameters may be preceded by a single question mark. +.PP +However, after CSI [ (or ESC [ [) a single character is read +and this entire sequence is ignored. +(The idea is to ignore an echoed function key.) +.PP +The action of a CSI sequence is determined by its final character. +.ad l +.TS +l l lx. +@ ICH T{ +Insert the indicated # of blank characters. +T} +A CUU T{ +Move cursor up the indicated # of rows. +T} +B CUD T{ +Move cursor down the indicated # of rows. +T} +C CUF T{ +Move cursor right the indicated # of columns. +T} +D CUB T{ +Move cursor left the indicated # of columns. +T} +E CNL T{ +Move cursor down the indicated # of rows, to column 1. +T} +F CPL T{ +Move cursor up the indicated # of rows, to column 1. +T} +G CHA T{ +Move cursor to indicated column in current row. +T} +H CUP T{ +Move cursor to the indicated row, column (origin at 1,1). +T} +J ED T{ +Erase display (default: from cursor to end of display). +T} + T{ +ESC [ 1 J: erase from start to cursor. +T} + T{ +ESC [ 2 J: erase whole display. +T} + T{ +ESC [ 3 J: erase whole display including scroll-back +buffer (since Linux 3.0). +T} +.\" ESC [ 3 J: commit f8df13e0a901fe55631fed66562369b4dba40f8b +K EL T{ +Erase line (default: from cursor to end of line). +T} + T{ +ESC [ 1 K: erase from start of line to cursor. +T} + T{ +ESC [ 2 K: erase whole line. +T} +L IL T{ +Insert the indicated # of blank lines. +T} +M DL T{ +Delete the indicated # of lines. +T} +P DCH T{ +Delete the indicated # of characters on current line. +T} +X ECH T{ +Erase the indicated # of characters on current line. +T} +a HPR T{ +Move cursor right the indicated # of columns. +T} +c DA T{ +Answer ESC [ ? 6 c: "I am a VT102". +T} +d VPA T{ +Move cursor to the indicated row, current column. +T} +e VPR T{ +Move cursor down the indicated # of rows. +T} +f HVP T{ +Move cursor to the indicated row, column. +T} +g TBC T{ +Without parameter: clear tab stop at current position. +T} + T{ +ESC [ 3 g: delete all tab stops. +T} +h SM Set Mode (see below). +l RM Reset Mode (see below). +m SGR Set attributes (see below). +n DSR Status report (see below). +q DECLL Set keyboard LEDs. + ESC [ 0 q: clear all LEDs + ESC [ 1 q: set Scroll Lock LED + ESC [ 2 q: set Num Lock LED + ESC [ 3 q: set Caps Lock LED +r DECSTBM T{ +Set scrolling region; parameters are top and bottom row. +T} +s ? Save cursor location. +u ? Restore cursor location. +\` HPA T{ +Move cursor to indicated column in current row. +T} +.TE +.ad +.PP +.B ECMA-48 Select Graphic Rendition +.PP +The ECMA-48 SGR sequence ESC [ \fIparameters\fP m sets display +attributes. +Several attributes can be set in the same sequence, separated by +semicolons. +An empty parameter (between semicolons or string initiator or +terminator) is interpreted as a zero. +.ad l +.TS +l lx. +param result +0 T{ +reset all attributes to their defaults +T} +1 set bold +2 T{ +set half-bright (simulated with color on a color display) +T} +3 set italic (since Linux 2.6.22; simulated with color on a color display) +4 T{ +set underscore (simulated with color on a color display) +(the colors used to simulate dim or underline are set +using ESC ] ...) +T} +5 set blink +7 set reverse video +10 T{ +reset selected mapping, display control flag, +and toggle meta flag (ECMA-48 says "primary font"). +T} +11 T{ +select null mapping, set display control flag, +reset toggle meta flag (ECMA-48 says "first alternate font"). +T} +12 T{ +select null mapping, set display control flag, +set toggle meta flag (ECMA-48 says "second alternate font"). +The toggle meta flag +causes the high bit of a byte to be toggled +before the mapping table translation is done. +T} +21 T{ +set underline; before Linux 4.17, this value +set normal intensity (as is done in many other terminals) +T} +22 set normal intensity +23 italic off (since Linux 2.6.22) +24 underline off +25 blink off +27 reverse video off +30 set black foreground +31 set red foreground +32 set green foreground +33 set brown foreground +34 set blue foreground +35 set magenta foreground +36 set cyan foreground +37 set white foreground +38 T{ +256/24-bit foreground color follows, shoehorned into 16 basic colors +(before Linux 3.16: set underscore on, set default foreground color) +T} +39 T{ +set default foreground color +(before Linux 3.16: set underscore off, set default foreground color) +T} +40 set black background +41 set red background +42 set green background +43 set brown background +44 set blue background +45 set magenta background +46 set cyan background +47 set white background +48 T{ +256/24-bit background color follows, shoehorned into 8 basic colors +T} +49 set default background color +90..97 T{ +set foreground to bright versions of 30..37 +T} +100..107 T{ +set background, same as 40..47 (bright not supported) +T} +.TE +.ad +.PP +Commands 38 and 48 require further arguments: +.TS +l lx. +;5;x T{ +256 color: values 0..15 are IBGR (black, red, green, ... white), +16..231 a 6x6x6 color cube, 232..255 a grayscale ramp +T} +;2;r;g;b T{ +24-bit color, r/g/b components are in the range 0..255 +T} +.TE +.PP +.B ECMA-48 Mode Switches +.TP +ESC [ 3 h +DECCRM (default off): Display control chars. +.TP +ESC [ 4 h +DECIM (default off): Set insert mode. +.TP +ESC [ 20 h +LF/NL (default off): Automatically follow echo of LF, VT, or FF with CR. +.\" +.PP +.B ECMA-48 Status Report Commands +.\" +.TP +ESC [ 5 n +Device status report (DSR): Answer is ESC [ 0 n (Terminal OK). +.TP +ESC [ 6 n +Cursor position report (CPR): Answer is ESC [ \fIy\fP ; \fIx\fP R, +where \fIx,y\fP is the cursor location. +.\" +.PP +.B DEC Private Mode (DECSET/DECRST) sequences +.PP +.\" +These are not described in ECMA-48. +We list the Set Mode sequences; +the Reset Mode sequences are obtained by replacing the final \[aq]h\[aq] +by \[aq]l\[aq]. +.TP +ESC [ ? 1 h +DECCKM (default off): When set, the cursor keys send an ESC O prefix, +rather than ESC [. +.TP +ESC [ ? 3 h +DECCOLM (default off = 80 columns): 80/132 col mode switch. +The driver sources note that this alone does not suffice; some user-mode +utility such as +.BR resizecons (8) +has to change the hardware registers on the console video card. +.TP +ESC [ ? 5 h +DECSCNM (default off): Set reverse-video mode. +.TP +ESC [ ? 6 h +DECOM (default off): When set, cursor addressing is relative to +the upper left corner of the scrolling region. +.TP +ESC [ ? 7 h +DECAWM (default on): Set autowrap on. +In this mode, a graphic +character emitted after column 80 (or column 132 of DECCOLM is on) +forces a wrap to the beginning of the following line first. +.TP +ESC [ ? 8 h +DECARM (default on): Set keyboard autorepeat on. +.TP +ESC [ ? 9 h +X10 Mouse Reporting (default off): Set reporting mode to 1 (or reset to +0)\[em]see below. +.TP +ESC [ ? 25 h +DECTECM (default on): Make cursor visible. +.TP +ESC [ ? 1000 h +X11 Mouse Reporting (default off): Set reporting mode to 2 (or reset +to 0)\[em]see below. +.\" +.PP +.B Linux Console Private CSI Sequences +.PP +.\" +The following sequences are neither ECMA-48 nor native VT102. +They are native to the Linux console driver. +Colors are in SGR parameters: +0 = black, 1 = red, 2 = green, 3 = brown, 4 = blue, 5 = magenta, 6 = +cyan, 7 = white; 8\[en]15 = bright versions of 0\[en]7. +.TS +l lx. +ESC [ 1 ; \fIn\fP ] T{ +Set color \fIn\fP as the underline color. +T} +ESC [ 2 ; \fIn\fP ] T{ +Set color \fIn\fP as the dim color. +T} +ESC [ 8 ] T{ +Make the current color pair the default attributes. +T} +ESC [ 9 ; \fIn\fP ] T{ +Set screen blank timeout to \fIn\fP minutes. +T} +ESC [ 10 ; \fIn\fP ] T{ +Set bell frequency in Hz. +T} +ESC [ 11 ; \fIn\fP ] T{ +Set bell duration in msec. +T} +ESC [ 12 ; \fIn\fP ] T{ +Bring specified console to the front. +T} +ESC [ 13 ] T{ +Unblank the screen. +T} +ESC [ 14 ; \fIn\fP ] T{ +Set the VESA powerdown interval in minutes. +T} +ESC [ 15 ] T{ +Bring the previous console to the front +(since Linux 2.6.0). +T} +ESC [ 16 ; \fIn\fP ] T{ +Set the cursor blink interval in milliseconds +(since Linux 4.2). +T} +.\" commit bd63364caa8df38bad2b25b11b2a1b849475cce5 +.TE +.SS Character sets +The kernel knows about 4 translations of bytes into console-screen +symbols. +The four tables are: a) Latin1 \-> PC, +b) VT100 graphics \-> PC, c) PC \-> PC, d) user-defined. +.PP +There are two character sets, called G0 and G1, and one of them +is the current character set. +(Initially G0.) +Typing \fB\[ha]N\fP causes G1 to become current, +\fB\[ha]O\fP causes G0 to become current. +.PP +These variables G0 and G1 point at a translation table, and can be +changed by the user. +Initially they point at tables a) and b), respectively. +The sequences ESC ( B and ESC ( 0 and ESC ( U and ESC ( K cause G0 to +point at translation table a), b), c), and d), respectively. +The sequences ESC ) B and ESC ) 0 and ESC ) U and ESC ) K cause G1 to +point at translation table a), b), c), and d), respectively. +.PP +The sequence ESC c causes a terminal reset, which is what you want if the +screen is all garbled. +The oft-advised "echo \[ha]V\[ha]O" will make only G0 current, +but there is no guarantee that G0 points at table a). +In some distributions there is a program +.BR reset (1) +that just does "echo \[ha][c". +If your terminfo entry for the console is correct +(and has an entry rs1=\eEc), then "tput reset" will also work. +.PP +The user-defined mapping table can be set using +.BR mapscrn (8). +The result of the mapping is that if a symbol c is printed, the symbol +s = map[c] is sent to the video memory. +The bitmap that corresponds to +s is found in the character ROM, and can be changed using +.BR setfont (8). +.SS Mouse tracking +The mouse tracking facility is intended to return +.BR xterm (1)-compatible +mouse status reports. +Because the console driver has no way to know +the device or type of the mouse, these reports are returned in the +console input stream only when the virtual terminal driver receives +a mouse update ioctl. +These ioctls must be generated by a mouse-aware +user-mode application such as the +.BR gpm (8) +daemon. +.PP +The mouse tracking escape sequences generated by +\fBxterm\fP(1) encode numeric parameters in a single character as +\fIvalue\fP+040. +For example, \[aq]!\[aq] is 1. +The screen coordinate system is 1-based. +.PP +The X10 compatibility mode sends an escape sequence on button press +encoding the location and the mouse button pressed. +It is enabled by sending ESC [ ? 9 h and disabled with ESC [ ? 9 l. +On button press, \fBxterm\fP(1) sends +ESC [ M \fIbxy\fP (6 characters). +Here \fIb\fP is button\-1, +and \fIx\fP and \fIy\fP are the x and y coordinates of the mouse +when the button was pressed. +This is the same code the kernel also produces. +.PP +Normal tracking mode (not implemented in Linux 2.0.24) sends an escape +sequence on both button press and release. +Modifier information is also sent. +It is enabled by sending ESC [ ? 1000 h and disabled with +ESC [ ? 1000 l. +On button press or release, \fBxterm\fP(1) sends ESC [ M +\fIbxy\fP. +The low two bits of \fIb\fP encode button information: +0=MB1 pressed, 1=MB2 pressed, 2=MB3 pressed, 3=release. +The upper bits encode what modifiers were down when the button was +pressed and are added together: 4=Shift, 8=Meta, 16=Control. +Again \fIx\fP and +\fIy\fP are the x and y coordinates of the mouse event. +The upper left corner is (1,1). +.SS Comparisons with other terminals +Many different terminal types are described, like the Linux console, +as being "VT100-compatible". +Here we discuss differences between the +Linux console and the two most important others, the DEC VT102 and +.BR xterm (1). +.\" +.PP +.B Control-character handling +.PP +The VT102 also recognized the following control characters: +.TP +NUL (0x00) +was ignored; +.TP +ENQ (0x05) +triggered an answerback message; +.TP +DC1 (0x11, \fB\[ha]Q\fP, XON) +resumed transmission; +.TP +DC3 (0x13, \fB\[ha]S\fP, XOFF) +caused VT100 to ignore (and stop transmitting) +all codes except XOFF and XON. +.PP +VT100-like DC1/DC3 processing may be enabled by the terminal driver. +.PP +The +.BR xterm (1) +program (in VT100 mode) recognizes the control characters +BEL, BS, HT, LF, VT, FF, CR, SO, SI, ESC. +.\" +.PP +.B Escape sequences +.PP +VT100 console sequences not implemented on the Linux console: +.TS +l l l. +ESC N SS2 T{ +Single shift 2. (Select G2 character set for the next character only.) +T} +ESC O SS3 T{ +Single shift 3. (Select G3 character set for the next character only.) +T} +ESC P DCS T{ +Device control string (ended by ESC \e) +T} +ESC X SOS Start of string. +ESC \[ha] PM Privacy message (ended by ESC \e) +ESC \e ST String terminator +ESC * ... Designate G2 character set +ESC + ... Designate G3 character set +.TE +.PP +The program +.BR xterm (1) +(in VT100 mode) recognizes ESC c, ESC # 8, ESC >, ESC =, +ESC D, ESC E, ESC H, ESC M, ESC N, ESC O, ESC P ... ESC \e, +ESC Z (it answers ESC [ ? 1 ; 2 c, "I am a VT100 with +advanced video option") +and ESC \[ha] ... ESC \e with the same meanings as indicated above. +It accepts ESC (, ESC ), ESC *, ESC + followed by 0, A, B for +the DEC special character and line drawing set, UK, and US-ASCII, +respectively. +.PP +The user can configure \fBxterm\fP(1) to respond to VT220-specific +control sequences, and it will identify itself as a VT52, VT100, and +up depending on the way it is configured and initialized. +.PP +It accepts ESC ] (OSC) for the setting of certain resources. +In addition to the ECMA-48 string terminator (ST), +\fBxterm\fP(1) accepts a BEL to terminate an OSC string. +These are a few of the OSC control sequences recognized by \fBxterm\fP(1): +.TS +l l. +ESC ] 0 ; \fItxt\fP ST T{ +Set icon name and window title to \fItxt\fP. +T} +ESC ] 1 ; \fItxt\fP ST Set icon name to \fItxt\fP. +ESC ] 2 ; \fItxt\fP ST Set window title to \fItxt\fP. +ESC ] 4 ; \fInum\fP; \fItxt\fP ST Set ANSI color \fInum\fP to \fItxt\fP. +ESC ] 10 ; \fItxt\fP ST Set dynamic text color to \fItxt\fP. +ESC ] 4 6 ; \fIname\fP ST T{ +Change log file to \fIname\fP (normally disabled by a compile-time option). +T} +ESC ] 5 0 ; \fIfn\fP ST Set font to \fIfn\fP. +.TE +.PP +It recognizes the following with slightly modified meaning +(saving more state, behaving closer to VT100/VT220): +.TS +l l l. +ESC 7 DECSC Save cursor +ESC 8 DECRC Restore cursor +.TE +.PP +It also recognizes +.TS +l l lx. +ESC F T{ +Cursor to lower left corner of screen (if enabled +by \fBxterm\fP(1)'s \fBhpLowerleftBugCompat\fP resource). +T} +ESC l Memory lock (per HP terminals). + Locks memory above the cursor. +ESC m Memory unlock (per HP terminals). +ESC n LS2 Invoke the G2 character set. +ESC o LS3 Invoke the G3 character set. +ESC | LS3R Invoke the G3 character set as GR. +ESC } LS2R Invoke the G2 character set as GR. +ESC \[ti] LS1R Invoke the G1 character set as GR. +.TE +.PP +It also recognizes ESC % and provides a more complete UTF-8 +implementation than Linux console. +.\" +.PP +.B CSI Sequences +.PP +Old versions of \fBxterm\fP(1), for example, from X11R5, +interpret the blink SGR as a bold SGR. +Later versions which implemented ANSI colors, for example, +XFree86 3.1.2A in 1995, improved this by allowing +the blink attribute to be displayed as a color. +Modern versions of xterm implement blink SGR as blinking text +and still allow colored text as an alternate rendering of SGRs. +Stock X11R6 versions did not recognize the color-setting SGRs until +the X11R6.8 release, which incorporated XFree86 xterm. +All ECMA-48 CSI sequences recognized by Linux are also recognized by +.IR xterm , +however \fBxterm\fP(1) implements several ECMA-48 and DEC control sequences +not recognized by Linux. +.PP +The \fBxterm\fP(1) +program recognizes all of the DEC Private Mode sequences listed +above, but none of the Linux private-mode sequences. +For discussion of \fBxterm\fP(1)'s +own private-mode sequences, refer to the +\fIXterm Control Sequences\fP +document by +Edward Moy, +Stephen Gildea, +and Thomas E.\& Dickey +available with the X distribution. +That document, though terse, is much longer than this manual page. +For a chronological overview, +.PP +.RS +.UR http://invisible\-island.net\:/xterm\:/xterm.log.html +.UE +.RE +.PP +details changes to xterm. +.PP +The \fIvttest\fP program +.PP +.RS +.UR http://invisible\-island.net\:/vttest/ +.UE +.RE +.PP +demonstrates many of these control sequences. +The \fBxterm\fP(1) source distribution also contains sample +scripts which exercise other features. +.SH NOTES +ESC 8 (DECRC) is not able to restore the character set changed with +ESC %. +.SH BUGS +In Linux 2.0.23, CSI is broken, and NUL is not ignored inside +escape sequences. +.PP +Some older kernel versions (after Linux 2.0) interpret 8-bit control +sequences. +These "C1 controls" use codes between 128 and 159 to replace +ESC [, ESC ] and similar two-byte control sequence initiators. +There are fragments of that in modern kernels (either overlooked or +broken by changes to support UTF-8), +but the implementation is incomplete and should be regarded +as unreliable. +.PP +Linux "private mode" sequences do not follow the rules in ECMA-48 +for private mode control sequences. +In particular, those ending with ] do not use a standard terminating +character. +The OSC (set palette) sequence is a greater problem, +since \fBxterm\fP(1) may interpret this as a control sequence +which requires a string terminator (ST). +Unlike the \fBsetterm\fP(1) sequences which will be ignored (since +they are invalid control sequences), the palette sequence will make +\fBxterm\fP(1) appear to hang (though pressing the return-key +will fix that). +To accommodate applications which have been hardcoded to use Linux +control sequences, +set the \fBxterm\fP(1) resource \fBbrokenLinuxOSC\fP to true. +.PP +An older version of this document implied that Linux recognizes the +ECMA-48 control sequence for invisible text. +It is ignored. +.SH SEE ALSO +.BR ioctl_console (2), +.BR charsets (7) |