[TriLUG] colorize stderr in bash

[Brian Phelps]

Thats interesting, not worried about doing it with files or certain
commands, I think I can figure out how to do that with sed.

I guess I'm looking for the short quick answer to "What line can I add
to .bashrc to get colorized stderr" 

I found one for zcsh, but I don't know how to get my shell, bash to do
something similar when I log in interactively.


On Wed, 2008-07-23 at 17:19 -0400, Kevin Hunter wrote:
> At 4:28p -0400 on Wed, 23 Jul 2008, Brian Phelps wrote:
> > Is there an easy way to colorize stderr in an interactive bash shell?
> 
> Obligatory disclaimer: be wary of using colors in the terminal.  Not all
> terminals/emulators are created equal, nor are ANSI escape sequences
> portable.  Colorized output that looks absolutely splendid on one
> author's machine may be barely readable on another's.  (e.g. Yellow text
> on black, and white backgrounds.)  Also, be aware that a significant
> portion of the population is colorblind, and for which colors have the
> opposite effect they might have for you.
> 
> Long answer:
> 
> That said, I prefer colors and think they're currently underutilized in
> the industry.  For those who *aren't* color blind, and who use ANSI
> capable terminals emulators colors can help identify breaks in longs
> scrolls of largely superfluous output text, or bring out warning or
> error messages.  For example, a tail of a web log and highlighting 404s
> (NOT FOUND), or 500s (SERVER ERROR)*, or parsing debug, informational,
> and warning messages from a compiler, or running program.  Some folks
> even colorize their command prompt.
> 
> Examples of programs in the wild that colorize (some) of their output
> django, pulseaudio.  I have found that the lightred lines move my eye
> directly where they need to be, and now I know what they mean; I don't
> have to reread them everytime to know what's up.
> 
> If you're worried about portability and playing-nice-with-others, I
> would caution you to make an *easy* opt-in or opt-out preference for
> those who do(n't) want colors.
> 
> Short answer: the same way you'd do it with stdout: with escapes.
> 
How do I get the shell to do it interactively?

> Some projects you might want to peruse:
> 
> http://scriptechocolor.sourceforge.net/
> http://www.scribd.com/doc/2099456/Advanced-BashScripting-Guide
> 
> Kevin
> 
> * Obviously, you don't want to clutter the logs with escape sequences,
> but what about piping to another program, e.g.
>    $ tail -f log | http-colorizer
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