Using color escape codes in less Post: 302237689

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Top Forums UNIX for Dummies Questions & Answers Using color escape codes in less Post 302237689 by Source2Exe on Thursday 18th of September 2008 07:23:52 AM

09-18-2008

Registered User

Using color escape codes in less

Hi all,
Not sure how "for dummies" this question is, but I'd better use understatement...

A. My Environment
==============
I am using RedHat Linux, version 2.6.18-53.el5.
When I type less --version I get:

less 394
Copyright (C) 1984-2005 Mark Nudelman
...

My terminal is configured as Xterm, using ANSI colors and indeed, typing
ls --color=yes produces a colored list.

B. Background
===========
I am using a small pearl script that colors lines of text according to predefined key words.
This is a very nice utility. When I redirect tail -f output to it, it produces nice color logs of my server, with words such as "Exception" or "Error" conveniently colored.

Recently I wanted to try a more ambitious use of this script: To use it together with less command.

Anyone can understand, that less +F is better than tail -f, as one can press CTRL+C at any given time when viewing a file online, and scroll or search within it effortlessly, without ever returning to the shell prompt.

Which leads me to:

C. The Problem
===========
1. I can not get less to show color.
Even typing "ls --color=yes > test.txt"
and then less -r text.txt or less -R text.txt NEVER displays the content in color. The output is actually the same as doing a "ls --color=no"

2. I read a bit about less input preprocessor the related Environment Variables in UNIX man pages : less ().

3.But, I can not figure out how I can turn less to use colors on a regular basis, How I can make less to "relay" all its output through my color pearl script, and mostly - Is it possible at all?

Any help would be highly appreciated.

Attached are my colorlogs.pl and colorlogs.conf files, to complement this post.

Thank you in advance.

Colorlogs.rar (1.5 KB)

Last edited by Source2Exe; 09-20-2008 at 11:13 AM.. Reason: Change icon

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LEARN ABOUT DEBIAN

xcolors

XCOLORS(1)						      General Commands Manual							XCOLORS(1)

NAME

       xcolors - display all X11 color names and colors

SYNOPSIS

       xcolors [ -start color ] [ -near color ] [ -distance howfar ]

DESCRIPTION

       xcolors reads the rgb.txt file that defines the color names the X server knows and displays the colors found.

       At  the top of the window is a sample region containing text.  By clicking on the color names, the color of the sample text can be changed.
       Mouse button 1 changes the foreground; button 2 changes the background.	The text can also be edited.

       Typing ``q'' exits the program.

OPTIONS

       In addition the the usual X Toolkit options, xcolors understands these command line options:

       -start name
	      specify a color name to start with; colors before this one in the rgb.txt file are skipped.  This option is useful if there are more
	      colors than will fit on your screen or in your colormap.

       -rgbfile filename
	      specify an alternate color database file to read.

       -near nearcolor
	      only show colors near this one in the RGB space.	All colors within a sphere in the RGB-space centered on nearcolor are displayed.

       -distance howfar
	      defines  how  close  colors  have  to  be to nearcolor to be displayed.  This option sets the radius of the sphere used by the -near
	      option.  The scale is such that the RGB cube is 256 units on a side.  The default is 64.

ACTIONS

       set-foreground([color])
	      Set the foreground color of the sample region.  If no color is provided, the color is taken from the  border  color  of  the  widget
	      where the action occurred.

       set-background([color])
	      Same as set-foreground() but sets the background color.

       quit() Exit xcolors.

RESOURCES

       Xcolors has a few top-level application resources that allow customizations that are specific to xcolors.

       startColor (classStartColor)
	      See the -start option.

       rgbFile (classRgbFile)
	      See the -rgbfile option.

       nearColor (classNearColor)
	      See the -near option.

       nearDistance (classNearDistance)
	      See the -distance option.

WIDGET HIERARCHY

       Knowing	the name and position in the hierarchy of each widget is useful when specifying resources for them.  In the chart below, the class
       and name of each widget is given.

       Xcolors xcolors
	    Paned panes
		 AsciiText sample
		 Viewport viewport
		      Box colors
			   Label colorname
			   Label colorname
			   .
			   .
			   .

FILES

       /etc/X11/rgb.txt
	      X color names and values.

BUGS

       Assumes that all names for the same color are consecutive in the rgb.txt file.

       Because xcolors cannot read the server's color name database, the color names it uses may not match those in  the  server.   This  is  most
       likely to happen if xcolors is run from a remote host.

       The program would be faster if it used gadgets instead of widgets for the color spots.

AUTHOR

       Stephen Gildea, MIT X Consortium

X Version 11							  3 October 1991							XCOLORS(1)