From 0381c2199dcea2a5ae0aeed85540b16b820d68a5 Mon Sep 17 00:00:00 2001
From: David Lawrence Ramsey <pooka109@gmail.com>
Date: Sat, 1 May 2004 01:21:38 +0000
Subject: [PATCH] clarifications to comments explaining exactly what control
characters and escape sequences are supported
git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@1725 35c25a1d-7b9e-4130-9fde-d3aeb78583b8
---
ChangeLog | 2 +
src/winio.c | 253 ++++++++++++++++++++++++++++++----------------------
2 files changed, 148 insertions(+), 107 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 5bd40080..ba9ce9d7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -31,6 +31,8 @@ CVS code -
shortcut_init(), die_save_file(), and nanogetstr().
- Call nano_disabled_msg() directly from the shortcut list
instead of inside the disabled functions. (David Benbennick)
+ - Clarifications to comments explaining exactly what control
+ characters and escape sequences are supported. (DLR)
- files.c:
add_open_file()
- Rearrange the NANO_SMALL #ifdef so that the code to set the
diff --git a/src/winio.c b/src/winio.c
index 2f05b35c..a0f07f9b 100644
--- a/src/winio.c
+++ b/src/winio.c
@@ -34,14 +34,63 @@ static int statblank = 0; /* Number of keystrokes left after
we call statusbar(), before we
actually blank the statusbar */
-/* Note on the following input routines: VT100s and derived terminals
- * generate Ctrl-H for Backspace and Ctrl-? (Ctrl-8) for Delete, while
- * VT220s/VT320s and derived terminals generate Ctrl-? (Ctrl-8) for
- * Backspace (VT320 only) and Esc [ 3 ~ for Delete (VT220/VT320). The
- * FreeBSD console is VT100-derived, but sometimes xterm wrongly assumes
- * it's VT220/VT320-derived. The workarounds for the problems that this
- * causes, in get_accepted_kbinput() and get_escape_seq_kbinput(), are
- * indicated by the comments beginning with "Terminal breakage". */
+/* Control character compatibility:
+ *
+ * - NANO_BACKSPACE_KEY is Ctrl-H, which is Backspace under ASCII, ANSI,
+ * VT100, and VT220.
+ * - NANO_TAB_KEY is Ctrl-I, which is Tab under ASCII, ANSI, VT100,
+ * VT220, and VT320.
+ * - NANO_ENTER_KEY is Ctrl-M, which is Enter under ASCII, ANSI, VT100,
+ * VT220, and VT320.
+ * - NANO_XON_KEY is Ctrl-Q, which is XON under ASCII, ANSI, VT100,
+ * VT220, and VT320.
+ * - NANO_XOFF_KEY is Ctrl-S, which is XOFF under ASCII, ANSI, VT100,
+ * VT220, and VT320.
+ * - NANO_CONTROL_8 is Ctrl-? (Ctrl-8), which is Delete under ASCII,
+ * ANSI, VT100, and VT220, and which is Backspace under VT320.
+ *
+ * Note: VT220s and VT320s also generate Esc [ 3 ~ for Delete. By
+ * default, xterm assumes it's running on a VT320 and generates Ctrl-?
+ * (Ctrl-8) for Backspace and Esc [ 3 ~ for Delete. This causes
+ * problems for VT100-derived terminals such as the FreeBSD console,
+ * which expect Ctrl-H for Backspace and Ctrl-? (Ctrl-8) for Delete, and
+ * on which the VT320 sequences are translated by the keypad to KEY_DC
+ * and [nothing]. We work around this conflict via the REBIND_DELETE
+ * flag: if it's not set, we assume VT320 compatibility, and if it is,
+ * we assume VT100 compatibility. Thanks to Lee Nelson and Wouter van
+ * Hemel for helping work this conflict out.
+ *
+ * Escape sequence compatibility:
+ *
+ * We support escape sequences for ANSI, VT100, VT220, VT320, the Linux
+ * console, the FreeBSD console, the Hurd console (a.k.a. the Mach
+ * console), xterm, rxvt, and Eterm. Among these, there are several
+ * conflicts and omissions, outlined as follows:
+ *
+ * - Tab on ANSI == PageUp on FreeBSD console; the former is omitted.
+ * (Ctrl-I is also Tab on ANSI, which we already support.)
+ * - PageDown on FreeBSD console == Center (5) on numeric keypad with
+ * NumLock off on Linux console; the latter is omitted. (The editing
+ * keypad key is more important to have working than the numeric
+ * keypad key, because the latter actually has no value when NumLock
+ * is off.)
+ * - F1 on FreeBSD console == the mouse key on xterm/rxvt/Eterm; the
+ * latter is omitted. (Mouse input will only work properly if the
+ * extended keypad value KEY_MOUSE is generated on mouse events
+ * instead of the escape sequence.)
+ * - F9 on FreeBSD console == PageDown on Hurd console; the former is
+ * omitted. (The editing keypad is more important to have working
+ * than the function keys, because the functions of the former are not
+ * arbitrary and the functions of the latter are.)
+ * - F10 on FreeBSD console == PageUp on Hurd console; the former is
+ * omitted. (Same as above.)
+ * - F13 on FreeBSD console == End on Hurd console; the former is
+ * omitted. (Same as above.)
+ * - The Hurd console has no escape sequences for F11, F12, F13, F14, or
+ * Center (5) on the numeric keypad with NumLock off.
+ *
+ * Note that Center (5) on the numeric keypad with NumLock off can also
+ * be the Begin key. */
/* Read in a single input character. If it's ignored, swallow it and go
* on. Otherwise, try to translate it from ASCII, extended keypad
@@ -199,12 +248,6 @@ int get_accepted_kbinput(WINDOW *win, int kbinput, int *meta_key)
break;
case 'O':
case 'o':
- /* Terminal breakage, part 1: When Delete is pressed,
- * xterm generates the VT220/VT320 sequence, Esc [ 3 ~,
- * for it instead of the VT100 sequence, Ctrl-?
- * (Ctrl-8). Work around this by always interpreting
- * the VT220/VT320 sequence as Delete. Thank you,
- * Wouter van Hemel. */
case '[':
{
int old_kbinput = kbinput, *escape_seq;
@@ -233,11 +276,6 @@ int get_accepted_kbinput(WINDOW *win, int kbinput, int *meta_key)
}
break;
case NANO_CONTROL_8:
- /* Terminal breakage, part 2: When Backspace is pressed,
- * xterm generates the VT320 sequence, Ctrl-? (Ctrl-8), for
- * it instead of the VT100 sequence, Ctrl-H. Work around
- * this by interpreting the VT320 sequence as Delete when
- * REBIND_DELETE isn't set, and as Backspace when it is. */
kbinput = ISSET(REBIND_DELETE) ? NANO_DELETE_KEY : NANO_BACKSPACE_KEY;
break;
case KEY_DOWN:
@@ -262,13 +300,6 @@ int get_accepted_kbinput(WINDOW *win, int kbinput, int *meta_key)
kbinput = NANO_BACKSPACE_KEY;
break;
case KEY_DC:
- /* Terminal breakage, part 3: When Backspace is pressed,
- * xterm generates the VT320 sequence, Ctrl-? (Ctrl-8), for
- * it instead of the VT100 sequence, Ctrl-H. Ctrl-?
- * (Ctrl-8) then gets translated into the keypad value
- * KEY_DC. Work around this by interpreting KEY_DC as
- * Delete when REBIND_DELETE isn't set, and as Backspace
- * when it is. Thank you, Lee Nelson. */
kbinput = ISSET(REBIND_DELETE) ? NANO_BACKSPACE_KEY : NANO_DELETE_KEY;
break;
case KEY_IC:
@@ -392,34 +423,7 @@ int get_ascii_kbinput(WINDOW *win, int kbinput)
/* Translate escape sequences, most of which correspond to extended
* keypad values. These sequences are generated when the terminal
* doesn't support the needed keys. Assume that Escape has already been
- * read in, and that nodelay(win) is TRUE.
- *
- * The supported terminals are the Linux console, the FreeBSD console,
- * the Hurd console (a.k.a. the Mach console), xterm, rxvt, and Eterm.
- * There are several escape sequence conflicts and omissions, outlined
- * as follows:
- *
- * - PageDown on FreeBSD console == Center (5) on numeric keypad with
- * NumLock off on Linux console. (The editing keypad key is more
- * important to have working than the numeric keypad key, because the
- * latter actually has no value when NumLock is off.)
- * - F1 on FreeBSD console == kmous on xterm/rxvt/Eterm; the latter is
- * omitted. (Mouse input will only work properly if the extended
- * keypad value KEY_MOUSE is generated on mouse events instead of the
- * kmous escape sequence.)
- * - F9 on FreeBSD console == PageDown on Hurd console; the former is
- * omitted. (The editing keypad is more important to have working
- * than the function keys, because the functions of the former are not
- * arbitrary and the functions of the latter are.)
- * - F10 on FreeBSD console == PageUp on Hurd console; the former is
- * omitted. (Same as above.)
- * - F13 on FreeBSD console == End on Hurd console; the former is
- * omitted. (Same as above.)
- * - The Hurd console has no escape sequences for F11, F12, F13, F14, or
- * Center (5) on the numeric keypad with NumLock off.
- *
- * Note that Center (5) on the numeric keypad with NumLock off can be
- * either kb2 or kbeg, or both. */
+ * read in, and that nodelay(win) is TRUE. */
int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
escape_seq_len)
{
@@ -443,10 +447,13 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
}
}
break;
- case 'A': /* Esc O A == Up on xterm. */
- case 'B': /* Esc O B == Down on xterm. */
- case 'C': /* Esc O C == Right on xterm. */
- case 'D': /* Esc O D == Left on xterm. */
+ case 'A': /* Esc O A == Up on VT100/VT320/xterm. */
+ case 'B': /* Esc O B == Down on
+ * VT100/VT320/xterm. */
+ case 'C': /* Esc O C == Right on
+ * VT100/VT320/xterm. */
+ case 'D': /* Esc O D == Left on
+ * VT100/VT320/xterm. */
kbinput = get_escape_seq_abcd(escape_seq[1]);
break;
case 'E': /* Esc O E == Center (5) on numeric keypad
@@ -460,19 +467,24 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
kbinput = NANO_HOME_KEY;
break;
case 'M': /* Esc O M == Enter on numeric keypad with
- * NumLock off on xterm/Eterm. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/Eterm. */
kbinput = NANO_ENTER_KEY;
break;
- case 'P': /* Esc O P == F1 on Hurd console. */
+ case 'P': /* Esc O P == F1 on VT100/VT220/VT320/Hurd
+ * console. */
kbinput = KEY_F(1);
break;
- case 'Q': /* Esc O Q == F2 on Hurd console. */
+ case 'Q': /* Esc O Q == F2 on VT100/VT220/VT320/Hurd
+ * console. */
kbinput = KEY_F(2);
break;
- case 'R': /* Esc O R == F3 on Hurd console. */
+ case 'R': /* Esc O R == F3 on VT100/VT220/VT320/Hurd
+ * console. */
kbinput = KEY_F(3);
break;
- case 'S': /* Esc O S == F4 on Hurd console. */
+ case 'S': /* Esc O S == F4 on VT100/VT220/VT320/Hurd
+ * console. */
kbinput = KEY_F(4);
break;
case 'T': /* Esc O T == F5 on Hurd console. */
@@ -500,67 +512,83 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
kbinput = get_escape_seq_abcd(escape_seq[1]);
break;
case 'j': /* Esc O j == '*' on numeric keypad with
- * NumLock off on xterm/rxvt. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = '*';
break;
case 'k': /* Esc O k == '+' on numeric keypad with
- * NumLock off on xterm/rxvt. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = '+';
break;
case 'l': /* Esc O l == ',' on numeric keypad with
- * NumLock off on xterm/rxvt. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = '+';
break;
case 'm': /* Esc O m == '-' on numeric keypad with
- * NumLock off on xterm/rxvt. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = '-';
break;
case 'n': /* Esc O n == Delete (.) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = NANO_DELETE_KEY;
break;
case 'o': /* Esc O o == '/' on numeric keypad with
- * NumLock off on xterm/rxvt. */
+ * NumLock off on
+ * VT100/VT220/VT320/xterm/rxvt. */
kbinput = '/';
break;
case 'p': /* Esc O p == Insert (0) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_INSERTFILE_KEY;
break;
case 'q': /* Esc O q == End (1) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_END_KEY;
break;
case 'r': /* Esc O r == Down (2) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_NEXTLINE_KEY;
break;
case 's': /* Esc O s == PageDown (3) on numeric
- * keypad with NumLock off on rxvt. */
+ * keypad with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_NEXTPAGE_KEY;
break;
case 't': /* Esc O t == Left (4) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_BACK_KEY;
break;
case 'u': /* Esc O u == Center (5) on numeric keypad
- * with NumLock off on rxvt/Eterm. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt/Eterm. */
kbinput = '5';
break;
case 'v': /* Esc O v == Right (6) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_FORWARD_KEY;
break;
case 'w': /* Esc O w == Home (7) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_HOME_KEY;
break;
case 'x': /* Esc O x == Up (8) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_PREVLINE_KEY;
break;
case 'y': /* Esc O y == PageUp (9) on numeric keypad
- * with NumLock off on rxvt. */
+ * with NumLock off on
+ * VT100/VT220/VT320/rxvt. */
kbinput = NANO_PREVPAGE_KEY;
break;
}
@@ -600,15 +628,18 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
* xterm/rxvt/Eterm. */
kbinput = KEY_F(5);
break;
- case '7': /* Esc [ 1 7 ~ == F6 on Linux
+ case '7': /* Esc [ 1 7 ~ == F6 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(6);
break;
- case '8': /* Esc [ 1 8 ~ == F7 on Linux
+ case '8': /* Esc [ 1 8 ~ == F7 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(7);
break;
- case '9': /* Esc [ 1 9 ~ == F8 on Linux
+ case '9': /* Esc [ 1 9 ~ == F8 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(8);
break;
@@ -650,8 +681,8 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
}
}
break;
- default: /* Esc [ 1 ~ == Home on Linux
- * console. */
+ default: /* Esc [ 1 ~ == Home on
+ * VT320/Linux console. */
kbinput = NANO_HOME_KEY;
break;
}
@@ -660,53 +691,60 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
case '2':
if (escape_seq_len >= 3) {
switch (escape_seq[2]) {
- case '0': /* Esc [ 2 0 ~ == F9 on Linux
+ case '0': /* Esc [ 2 0 ~ == F9 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(9);
break;
- case '1': /* Esc [ 2 1 ~ == F10 on Linux
+ case '1': /* Esc [ 2 1 ~ == F10 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(10);
break;
- case '3': /* Esc [ 2 3 ~ == F11 on Linux
+ case '3': /* Esc [ 2 3 ~ == F11 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(11);
break;
- case '4': /* Esc [ 2 4 ~ == F12 on Linux
+ case '4': /* Esc [ 2 4 ~ == F12 on
+ * VT220/VT320/Linux
* console/xterm/rxvt/Eterm. */
kbinput = KEY_F(12);
break;
- case '5': /* Esc [ 2 5 ~ == F13 on Linux
+ case '5': /* Esc [ 2 5 ~ == F13 on
+ * VT220/VT320/Linux
* console/rxvt/Eterm. */
kbinput = KEY_F(13);
break;
- case '6': /* Esc [ 2 6 ~ == F14 on Linux
+ case '6': /* Esc [ 2 6 ~ == F14 on
+ * VT220/VT320/Linux
* console/rxvt/Eterm. */
kbinput = KEY_F(14);
break;
- default: /* Esc [ 2 ~ == Insert on Linux
+ default: /* Esc [ 2 ~ == Insert on
+ * VT220/VT320/Linux
* console/xterm. */
kbinput = NANO_INSERTFILE_KEY;
break;
}
}
break;
- case '3': /* Esc [ 3 ~ == Delete on Linux
- * console/xterm. */
+ case '3': /* Esc [ 3 ~ == Delete on
+ * VT220/VT320/Linux console/xterm. */
kbinput = NANO_DELETE_KEY;
break;
- case '4': /* Esc [ 4 ~ == End on Linux
+ case '4': /* Esc [ 4 ~ == End on VT220/VT320/Linux
* console/xterm. */
kbinput = NANO_END_KEY;
break;
- case '5': /* Esc [ 5 ~ == PageUp on Linux
- * console/xterm; Esc [ 5 ^ == PageUp on
- * Eterm. */
+ case '5': /* Esc [ 5 ~ == PageUp on
+ * VT220/VT320/Linux console/xterm; Esc [
+ * 5 ^ == PageUp on Eterm. */
kbinput = NANO_PREVPAGE_KEY;
break;
- case '6': /* Esc [ 6 ~ == PageDown on Linux
- * console/xterm; Esc [ 6 ^ == PageDown on
- * Eterm. */
+ case '6': /* Esc [ 6 ~ == PageDown on
+ * VT220/VT320/Linux console/xterm; Esc [
+ * 6 ^ == PageDown on Eterm. */
kbinput = NANO_NEXTPAGE_KEY;
break;
case '7': /* Esc [ 7 ~ == Home on rxvt. */
@@ -721,15 +759,16 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
case '@': /* Esc [ @ == Insert on Hurd console. */
kbinput = NANO_INSERTFILE_KEY;
break;
- case 'A': /* Esc [ A == Up on Linux console/FreeBSD
- * console/Hurd console/rxvt/Eterm. */
- case 'B': /* Esc [ B == Down on Linux
+ case 'A': /* Esc [ A == Up on ANSI/VT220/Linux
+ * console/FreeBSD console/Hurd
+ * console/rxvt/Eterm. */
+ case 'B': /* Esc [ B == Down on ANSI/VT220/Linux
* console/FreeBSD console/Hurd
* console/rxvt/Eterm. */
- case 'C': /* Esc [ C == Right on Linux
+ case 'C': /* Esc [ C == Right on ANSI/VT220/Linux
* console/FreeBSD console/Hurd
* console/rxvt/Eterm. */
- case 'D': /* Esc [ D == Left on Linux
+ case 'D': /* Esc [ D == Left on ANSI/VT220/Linux
* console/FreeBSD console/Hurd
* console/rxvt/Eterm. */
kbinput = get_escape_seq_abcd(escape_seq[1]);
@@ -746,7 +785,7 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
* console. */
kbinput = NANO_NEXTPAGE_KEY;
break;
- case 'H': /* Esc [ H == Home on FreeBSD
+ case 'H': /* Esc [ H == Home on ANSI/VT220/FreeBSD
* console/Hurd console/Eterm. */
kbinput = NANO_HOME_KEY;
break;
@@ -754,7 +793,7 @@ int get_escape_seq_kbinput(WINDOW *win, int *escape_seq, size_t
* console. */
kbinput = NANO_PREVPAGE_KEY;
break;
- case 'L': /* Esc [ L == Insert on FreeBSD
+ case 'L': /* Esc [ L == Insert on ANSI/FreeBSD
* console. */
kbinput = NANO_INSERTFILE_KEY;
break;
--
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