"less" command output-I cannot scroll through it !

deepclutch · 03-14-2008, 11:26 PM

So,konsole doesnot support scrolling through "less" output.
@ararus:will try that!
most of the time I am on Debian Sid(Gnome-2.22),but with archlinux+kdemod,konsole is becoming a PITA.

guess,I have to search for some alternate terminals.

also,will try to post this in konsole(kde) BTS maybe!

any KDE users can confirm this problem?

deepclutch · 03-15-2008, 12:37 AM

OK.I have filed a bug report(wish list

) in Kde BTS here:
http://bugs.kde.org/show_bug.cgi?id=159340

Tinkster · 03-15-2008, 02:00 AM

Quote:

Originally Posted by deepclutch

OK.I have filed a bug report(wish list :p ) in Kde BTS here:
http://bugs.kde.org/show_bug.cgi?id=159340

And another bump after 1 hour? My friend, next time I'll give
you an out-time of a few days ...

Cheers,
Tink

exit3219 · 03-15-2008, 03:33 AM

FWIW, in vim you have to do :set mouse=a to make it react to mouse events. I don't know if/how this can be done with less.

deepclutch · 03-15-2008, 03:43 AM

@ararus:I tried
echo -e '\e[?1000h'.I opened a file with "less" and tried mouse to scroll-but that brings the "help" message of "less" command.

also after echoing above thing,when I use mouse inside konsole,it just prints some hex messages and "beep" sound

To escape,I echoed:

echo -e '\e[?1000l'

@exit3219:but even nano editor also allows mouse scrolling :?

@Tinkster:why are u getting offended?I am not in a raw into bumping JFYI.cool down!dont use ur time to cr@p this thread.stop this behaviour,atleast ur a mod(?).

Thanks All,
Cheers

exit3219 · 03-15-2008, 07:12 AM

http://bugs.kde.org/show_bug.cgi?id=159340#c2

ararus · 03-16-2008, 12:05 PM

Quote:

@ararus:I tried
echo -e '\e[?1000h'.I opened a file with "less" and tried mouse to scroll-but that brings the "help" message of "less" command.

also after echoing above thing,when I use mouse inside konsole,it just prints some hex messages and "beep" sound

Yes, that's what I said would happen, it merely prints the raw escape sequences to the console. That's Phase 1. Phase 2 is getting the relevant application to interpret those escape sequences properly, less isn't going to magically understand those escape sequences just because you told the terminal to print them. While less has configurable key bindings, the escape sequences contain the x/y coordinates on screen, so less will need to be modified to understand the sequences.

ararus · 03-19-2008, 02:12 PM

OK, I wrote a quick hack to allow less to handle the mouse key sequences.

Code:

diff -u -X diff_ignore/less less-418.orig/cmd.h less-418/cmd.h
--- less-418.orig/cmd.h	2007-06-15 23:06:23.000000000 +0100
+++ less-418/cmd.h	2008-03-18 10:51:02.000000000 +0000
@@ -72,6 +72,8 @@
 #define	A_END_LIST		103
 #define	A_SPECIAL_KEY		104
 
+#define A_MOUSE			126
+
 #define A_SKIP			127
 
 #define	A_EXTRA			0200
@@ -129,3 +131,17 @@
 #define SK_BACKTAB		15
 #define SK_CTL_BACKSPACE	16
 #define SK_CONTROL_K		40
+
+#define M_BTN1			1
+#define M_BTN2			2
+#define M_BTN3			3
+#define M_BTN4			4
+#define M_BTN5			5
+#define M_BTN_FIRST		M_BTN1
+#define M_BTN_LAST		M_BTN5
+
+#define M_BTN_RELEASE		0x23
+
+#define MOD_NONE		1
+#define MOD_ALT			2
+#define MOD_CTRL		4
diff -u -X diff_ignore/less less-418.orig/command.c less-418/command.c
--- less-418.orig/command.c	2007-12-10 16:40:37.000000000 +0000
+++ less-418/command.c	2008-03-18 10:51:02.000000000 +0000
@@ -899,6 +899,7 @@
 	IFILE old_ifile;
 	IFILE new_ifile;
 	char *tagfile;
+	char btn[3];
 
 	search_type = SRCH_FORW;
 	wscroll = (sc_height + 1) / 2;
@@ -1021,6 +1022,7 @@
 		if (action != A_PREFIX)
 			cmd_reset();
 
+action:
 		switch (action)
 		{
 		case A_DIGIT:
@@ -1652,6 +1654,25 @@
 			screen_trashed = 1;
 			break;
 
+		case A_MOUSE:
+			cmd_reset();
+
+			if (decode_button(btn))
+				break;
+
+			btn[2] = 0;
+			extra = NULL;
+			action = bcmd_decode(&btn, &extra);
+
+			switch (action) {
+			case A_INVALID:
+			case A_NOACTION:
+				break;
+
+			default:
+				goto action;
+			}
+
 		case A_PREFIX:
 			/*
 			 * The command is incomplete (more chars are needed).
diff -u -X diff_ignore/less less-418.orig/decode.c less-418/decode.c
--- less-418.orig/decode.c	2007-12-10 16:35:52.000000000 +0000
+++ less-418/decode.c	2008-03-18 10:51:02.000000000 +0000
@@ -66,6 +66,7 @@
 	CONTROL('D'),0,			A_F_SCROLL,
 	'u',0,				A_B_SCROLL,
 	CONTROL('U'),0,			A_B_SCROLL,
+	ESC,'[','M',0,			A_MOUSE,
 	' ',0,				A_F_SCREEN,
 	'f',0,				A_F_SCREEN,
 	CONTROL('F'),0,			A_F_SCREEN,
@@ -201,6 +202,45 @@
 	SK(SK_UP_ARROW),0,		EC_UP,		/* UPARROW */
 	ESC,'j',0,			EC_DOWN,	/* ESC j */
 	SK(SK_DOWN_ARROW),0,		EC_DOWN,	/* DOWNARROW */
+	ESC,'[','M',0,			A_MOUSE,
+};
+
+static unsigned char cmdbtntable[] =
+{
+	MOD_NONE,M_BTN4,0,		A_B_SCROLL,
+	MOD_NONE,M_BTN5,0,		A_F_SCROLL,
+	MOD_CTRL,M_BTN4,0,		A_B_LINE,
+	MOD_CTRL,M_BTN5,0,		A_F_LINE,
+	MOD_ALT,M_BTN4,0,		A_B_SCREEN,
+	MOD_ALT,M_BTN5,0,		A_F_SCREEN,
+	MOD_NONE,M_BTN1,0,		A_AGAIN_SEARCH,
+	MOD_NONE,M_BTN3,0,		A_REVERSE_SEARCH,
+	MOD_CTRL,M_BTN1,0,		A_T_AGAIN_SEARCH,
+	MOD_CTRL,M_BTN3,0,		A_T_REVERSE_SEARCH,
+	MOD_NONE,M_BTN2,0,		A_NOACTION,
+	MOD_CTRL,M_BTN2,0,		A_NOACTION,
+	MOD_ALT,M_BTN1,0,		A_NOACTION,
+	MOD_ALT,M_BTN2,0,		A_NOACTION,
+	MOD_ALT,M_BTN3,0,		A_NOACTION,
+};
+
+static unsigned char editbtntable[] =
+{
+	MOD_NONE,M_BTN1,0,		A_NOACTION,
+	MOD_NONE,M_BTN2,0,		A_NOACTION,
+	MOD_NONE,M_BTN3,0,		A_NOACTION,
+	MOD_NONE,M_BTN4,0,		EC_UP,
+	MOD_NONE,M_BTN5,0,		EC_DOWN,
+	MOD_CTRL,M_BTN1,0,		A_NOACTION,
+	MOD_CTRL,M_BTN2,0,		A_NOACTION,
+	MOD_CTRL,M_BTN3,0,		A_NOACTION,
+	MOD_CTRL,M_BTN4,0,		A_NOACTION,
+	MOD_CTRL,M_BTN5,0,		A_NOACTION,
+	MOD_ALT,M_BTN1,0,		A_NOACTION,
+	MOD_ALT,M_BTN2,0,		A_NOACTION,
+	MOD_ALT,M_BTN3,0,		A_NOACTION,
+	MOD_ALT,M_BTN4,0,		A_NOACTION,
+	MOD_ALT,M_BTN5,0,		A_NOACTION,
 };
 
 /*
@@ -218,6 +258,8 @@
  */
 static struct tablelist *list_fcmd_tables = NULL;
 static struct tablelist *list_ecmd_tables = NULL;
+static struct tablelist *list_cb_cmd_tables = NULL;
+static struct tablelist *list_eb_cmd_tables = NULL;
 static struct tablelist *list_var_tables = NULL;
 static struct tablelist *list_sysvar_tables = NULL;
 
@@ -294,6 +336,8 @@
 	 */
 	add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
 	add_ecmd_table((char*)edittable, sizeof(edittable));
+	add_cb_cmd_table((char*)cmdbtntable, sizeof(cmdbtntable));
+	add_eb_cmd_table((char*)editbtntable, sizeof(editbtntable));
 #if USERFILE
 	/*
 	 * For backwards compatibility,
@@ -368,6 +412,27 @@
 }
 
 /*
+ * Add a mouse button command table.
+ */
+	public void
+add_cb_cmd_table(buf, len)
+	char *buf;
+	int len;
+{
+	if (add_cmd_table(&list_cb_cmd_tables, buf, len) < 0)
+		error("Warning: some edit commands disabled", NULL_PARG);
+}
+
+	public void
+add_eb_cmd_table(buf, len)
+	char *buf;
+	int len;
+{
+	if (add_cmd_table(&list_eb_cmd_tables, buf, len) < 0)
+		error("Warning: some edit commands disabled", NULL_PARG);
+}
+
+/*
  * Add an environment variable table.
  */
 	static void
@@ -518,7 +583,29 @@
 	char *cmd;
 	char **sp;
 {
-	return (cmd_decode(list_ecmd_tables, cmd, sp));
+	char btn[3];
+	int action = cmd_decode(list_ecmd_tables, cmd, sp);
+
+	if (action == A_MOUSE) {
+		if (decode_button(btn)) {
+			return (A_NOACTION);
+		}
+
+		btn[2] = 0;
+		return (cmd_decode(list_eb_cmd_tables, btn, sp));
+	}
+	return (action);
+}
+
+/*
+ * Decode a command from the cmdbtntables list.
+ */
+	public int
+bcmd_decode(cmd,sp)
+	char *cmd;
+	char **sp;
+{
+	return (cmd_decode(list_cb_cmd_tables, cmd, sp));
 }
 
 /*
@@ -619,6 +706,16 @@
 			add_ecmd_table(p, n);
 			p += n;
 			break;
+		case CMD_BTN_SECTION:
+			n = gint(&p);
+			add_cb_cmd_table(p, n);
+			p += n;
+			break;
+		case EDIT_BTN_SECTION:
+			n = gint(&p);
+			add_eb_cmd_table(p, n);
+			p += n;
+			break;
 		case VAR_SECTION:
 			n = gint(&p);
 			add_var_table((sysvar) ? 
@@ -837,3 +934,39 @@
 	return action;
 }
 
+
+/*
+ * Read a character and decode into mod + button.
+ *
+ * Bits 0-1 = Button number (buttons 0-2, 3 is release).
+ * Bit 2 = Shift status (according to rxvtRef, but why?).
+ * Bit 3 = Alt/Meta status.
+ * Bit 4 = Control status.
+ * Bit 5 = Always set to make the character printable (i.e. >space).
+ * Bit 6 = Indicates a wheel event (bit 0 is up/down).
+ * Bit 7 = Unknown.
+ *
+ * Return 0 if OK, 1 if button should be ignored (button release).
+ */
+	public int
+decode_button(btn)
+	char btn[2];
+{
+	int b = getcc();
+
+	/* Discard x/y coordinates. */
+	getcc();
+	getcc();
+
+	/* Ignore release events. */
+	if ((b & 0x23) == M_BTN_RELEASE)
+		return (1);
+
+	btn[0] = (b & 0x1c) >> 2;
+	if (!btn[0]) btn[0] = 1;
+
+	btn[1] = (b & 3) | ((b & 0x40) >> 4);
+	if (btn[1] < 4) (btn[1])++;
+
+	return (0);
+}
diff -u -X diff_ignore/less less-418.orig/funcs.h less-418/funcs.h
--- less-418.orig/funcs.h	2008-01-01 00:51:17.000000000 +0000
+++ less-418/funcs.h	2008-03-18 10:51:02.000000000 +0000
@@ -86,8 +86,11 @@
 	public void init_cmds ();
 	public void add_fcmd_table ();
 	public void add_ecmd_table ();
+	public void add_cb_cmd_table ();
+	public void add_eb_cmd_table ();
 	public int fcmd_decode ();
 	public int ecmd_decode ();
+	public int bcmd_decode ();
 	public char * lgetenv ();
 	public int lesskey ();
 	public void add_hometable ();
@@ -270,3 +273,6 @@
 	public void open_getchr ();
 	public void close_getchr ();
 	public int getchr ();
+	public void xwin_mouse_on ();
+	public void xwin_mouse_off ();
+	public int decode_button(char btn[2]);
diff -u -X diff_ignore/less less-418.orig/less.h less-418/less.h
--- less-418.orig/less.h	2007-12-04 20:23:30.000000000 +0000
+++ less-418/less.h	2008-03-18 10:51:02.000000000 +0000
@@ -468,6 +468,7 @@
 #define	S_INTERRUPT	01
 #define	S_STOP		02
 #define S_WINCH		04
+#define S_TERM		8
 #define	ABORT_SIGS()	(sigs & (S_INTERRUPT|S_STOP))
 
 #define	QUIT_OK		0
diff -u -X diff_ignore/less less-418.orig/lesskey.c less-418/lesskey.c
--- less-418.orig/lesskey.c	2007-12-10 16:35:52.000000000 +0000
+++ less-418/lesskey.c	2008-03-18 10:51:02.000000000 +0000
@@ -185,6 +185,8 @@
 
 struct table cmdtable;
 struct table edittable;
+struct table cbtntable;
+struct table ebtntable;
 struct table vartable;
 struct table *currtable = &cmdtable;
 
@@ -201,6 +203,8 @@
 };
 char cmdsection[1] =	{ CMD_SECTION };
 char editsection[1] =	{ EDIT_SECTION };
+char cbtnsection[1] =	{ CMD_BTN_SECTION };
+char ebtnsection[1] =	{ EDIT_BTN_SECTION };
 char varsection[1] =	{ VAR_SECTION };
 char endsection[1] =	{ END_SECTION };
 
@@ -344,6 +348,12 @@
 	edittable.names = editnames;
 	edittable.pbuffer = edittable.buffer;
 
+	cbtntable.names = cmdnames;
+	cbtntable.pbuffer = cbtntable.buffer;
+
+	ebtntable.names = editnames;
+	ebtntable.pbuffer = ebtntable.buffer;
+
 	vartable.names = NULL;
 	vartable.pbuffer = vartable.buffer;
 }
@@ -556,6 +566,16 @@
 		currtable = &vartable;
 		return (1);
 	}
+	if (PREFIX(s, "#cmdbutton"))
+	{
+		currtable = &cbtntable;
+		return (1);
+	}
+	if (PREFIX(s, "#editbutton"))
+	{
+		currtable = &ebtntable;
+		return (1);
+	}
 	if (PREFIX(s, "#stop"))
 	{
 		add_cmd_char('\0');
@@ -699,6 +719,48 @@
 }
 
 	void
+parse_btnline(p)
+	char *p;
+{
+	char buf[2];
+	int c;
+	int action;
+
+	buf[0] = MOD_NONE;
+	buf[1] = 0;
+
+	c = tolower(*p++);
+	if (c == 'c') {
+		buf[0] = MOD_CTRL;
+		c = *p++;
+	} else if (c == 'a') {
+		buf[0] = MOD_ALT;
+		c = *p++;
+	}
+
+	c -= '0';
+	if (c >= M_BTN_FIRST && c <= M_BTN_LAST) {
+		buf[1] = c;
+	} else {
+		error("bad button number");
+		return;
+	}
+
+	p = skipsp(p);
+	if (*p == '\0')
+	{
+		error("missing action");
+		return;
+	}
+
+	add_cmd_char(buf[0]);
+	add_cmd_char(buf[1]);
+	add_cmd_char('\0');
+	action = findaction(p);
+	add_cmd_char(action);
+}
+
+	void
 parse_varline(p)
 	char *p;
 {
@@ -755,10 +817,13 @@
 	if (*p == '\0')
 		return;
 
-	if (currtable == &vartable)
+	if (currtable == &vartable) {
 		parse_varline(p);
-	else
+	} else if (currtable == &cbtntable || currtable == &ebtntable) {
+		parse_btnline(p);
+	} else {
 		parse_cmdline(p);
+	}
 }
 
 	int
@@ -859,6 +924,16 @@
 	fputint(out, edittable.pbuffer - edittable.buffer);
 	fputbytes(out, (char *)edittable.buffer, edittable.pbuffer-edittable.buffer);
 
+	/* Cmd button section */
+	fputbytes(out, cbtnsection, sizeof(cbtnsection));
+	fputint(out, cbtntable.pbuffer - cbtntable.buffer);
+	fputbytes(out, (char *)cbtntable.buffer, cbtntable.pbuffer-cbtntable.buffer);
+
+	/* Edit button section */
+	fputbytes(out, ebtnsection, sizeof(ebtnsection));
+	fputint(out, ebtntable.pbuffer - ebtntable.buffer);
+	fputbytes(out, (char *)ebtntable.buffer, ebtntable.pbuffer-ebtntable.buffer);
+
 	/* Environment variable section */
 	fputbytes(out, varsection, sizeof(varsection)); 
 	fputint(out, vartable.pbuffer - vartable.buffer);
diff -u -X diff_ignore/less less-418.orig/lesskey.h less-418/lesskey.h
--- less-418.orig/lesskey.h	2007-06-15 23:06:24.000000000 +0100
+++ less-418/lesskey.h	2008-03-18 10:51:02.000000000 +0000
@@ -29,6 +29,8 @@
 
 #define	CMD_SECTION		'c'
 #define	EDIT_SECTION		'e'
+#define CMD_BTN_SECTION		'b'
+#define EDIT_BTN_SECTION	'B'
 #define	VAR_SECTION		'v'
 #define	END_SECTION		'x'
 
diff -u -X diff_ignore/less less-418.orig/screen.c less-418/screen.c
--- less-418.orig/screen.c	2008-01-01 00:50:42.000000000 +0000
+++ less-418/screen.c	2008-03-18 10:51:02.000000000 +0000
@@ -210,6 +210,8 @@
 static void tmodes();
 #endif
 
+static int use_mouse;		/* Enable XWin mouse button reporting */
+
 /*
  * These two variables are sometimes defined in,
  * and needed by, the termcap library.
@@ -1559,6 +1561,12 @@
 	initcolor();
 	flush();
 #endif
+
+	if (getenv("LESSUSEMOUSE")) {
+		use_mouse = 1;
+		xwin_mouse_on();
+	}
+
 	init_done = 1;
 }
 
@@ -1586,6 +1594,7 @@
 	clreol();
 #endif
 #endif
+	xwin_mouse_off();
 	init_done = 0;
 }
 
@@ -2498,3 +2507,22 @@
 #endif
 }
 #endif
+
+#define XWIN_MOUSE_ON	"\033[?1000h"
+#define XWIN_MOUSE_OFF	"\033[?1000l"
+
+	public void
+xwin_mouse_on()
+{
+	if (use_mouse) {
+		tputs(XWIN_MOUSE_ON, 1, putchr);
+	}
+}
+
+	public void
+xwin_mouse_off()
+{
+	if (use_mouse) {
+		tputs(XWIN_MOUSE_OFF, 1, putchr);
+	}
+}
diff -u -X diff_ignore/less less-418.orig/signal.c less-418/signal.c
--- less-418.orig/signal.c	2007-12-10 16:35:52.000000000 +0000
+++ less-418/signal.c	2008-03-18 10:51:02.000000000 +0000
@@ -78,6 +78,22 @@
 }
 #endif
 
+#ifdef SIGTERM
+/*
+ * Term signal handler.
+ */
+	/* ARGSUSED*/
+	static RETSIGTYPE
+term(type)
+	int type;
+{
+	LSIGNAL(SIGTERM, term);
+	sigs |= S_TERM;
+	if (reading)
+		intread();
+}
+#endif
+
 #ifdef SIGWINCH
 /*
  * "Window" change handler
@@ -161,6 +177,9 @@
 #ifdef SIGQUIT
 		(void) LSIGNAL(SIGQUIT, SIG_IGN);
 #endif
+#ifdef SIGTERM
+		(void) LSIGNAL(SIGTERM, term);
+#endif
 	} else
 	{
 		/*
@@ -271,4 +290,10 @@
 		}
 
 	}
+#ifdef S_TERM
+	if (tsignals & S_TERM)
+	{
+		quit(QUIT_OK);
+	}
+#endif
 }

I used the current version, 418, it may work with other versions, but you might as well get the latest source.

Define the environment variable LESSUSEMOUSE to enable the mouse.

Default actions:

wheel up/down: scroll half a page
ctrl + wheel: scroll 1 line
alt + wheel: scroll full page (may not work)

button1/button3 will do a next/prev search.

NOTE: Alt+wheel works in rxvt, but not in xterm, but there may be an option to enable it. Don't know about other terminals. The window manager may also eat certain combinations, of course.

NOTE: You'll see I only used Control and Alt, you generally cannot bind Shift since mouse reporting is disabled while Shift is held down (to enable making selections).

You can change the bindings in your lesskey file, section #cmdbutton for command mode, #editbutton for edit mode (the prompt line), key names are the button number (4/5 for wheel), optionally prefixed with 'c' or 'a' (case insensitive) for ctrl/alt.

e.g.

Code:

#cmdbutton
4	back-line
5	forw-line
c4	back-scroll
c5	forw-scroll

will swap the behaviour of (plain) wheel and ctrl+wheel.

In edit mode, the wheel will scroll through the search history. None of the other buttons do anything by default, but you can bind them in the #editbutton section, as mentioned above. Using the mouse in edit mode doesn't seem that useful to me, but it has to interpret the escape sequences or the'll just be dumped into the input buffer.

deepclutch · 03-20-2008, 10:52 AM

well,what I have to do with this script

yes,obviously on archlinux,I have the same version of less.
where should I place this script?

Thank you!

EDIT:Now,as per kde BTS,this "bug"(wishlist) is RESOLVED and FIXED:-
see here:
https://bugs.kde.org/show_bug.cgi?id=159340

Quote:

SVN commit 786780 by knight:

If the terminal application is not interested in mouse events and the display's scroll bar is not movable then send Up/Down key press events to the terminal instead.

This makes it possible to scroll up and down in 'less' and other applications using the mouse wheel. One key press is sent for every 5 degrees of mouse wheel rotation. Typical mouse wheels operate in steps of 15 degrees which equals 3 lines scrolled per notch. This default is the same as Vim's default mouse wheel scroll step.

As in gnome-terminal and others, this has side effects such as the mouse wheel scrolling through history results in the shell if the shell is run in a program such as screen.

BUG: 159340

M +36 -1 TerminalDisplay.cpp
M +3 -0 TerminalDisplay.h

WebSVN link: http://websvn.kde.org/?view=rev&revision=786780

ararus · 03-21-2008, 01:07 PM

You need to apply it to the source and recompile. Save the patch as, say, less-mouse.diff.

Code:

tar zxf less-418.tar.gz
cd less-418
patch -p1 -i ../less-mouse.diff
./configure && make

Install it wherever.

libcha · 04-16-2010, 08:48 AM

ararus: i tried your solution, but doesn't work. my new compiled less behaves the same as the original. [kanotix (debian lenny)]