gettext: The --color option

 
 9.11.1 The ‘--color’ option
 ---------------------------
 
    The ‘--color=WHEN’ option specifies under which conditions colorized
 output should be generated.  The WHEN part can be one of the following:
 
 ‘always’
 ‘yes’
      The output will be colorized.
 
 ‘never’
 ‘no’
      The output will not be colorized.
 
 ‘auto’
 ‘tty’
      The output will be colorized if the output device is a tty, i.e.
      when the output goes directly to a text screen or terminal emulator
      window.
 
 ‘html’
      The output will be colorized and be in HTML format.
 
 ‘test’
      This is a special value, understood only by the ‘msgcat’ program.
      It is explained in the next section (⇒The TERM variable).
 
 ‘--color’ is equivalent to ‘--color=yes’.  The default is
 ‘--color=auto’.
 
    Thus, a command like ‘msgcat vi.po’ will produce colorized output
 when called by itself in a command window.  Whereas in a pipe, such as
 ‘msgcat vi.po | less -R’, it will not produce colorized output.  To get
 colorized output in this situation nevertheless, use the command ‘msgcat
 --color vi.po | less -R’.
 
    The ‘--color=html’ option will produce output that can be viewed in a
 browser.  This can be useful, for example, for Indic languages, because
 the renderic of Indic scripts in browsers is usually better than in
 terminal emulators.
 
    Note that the output produced with the ‘--color’ option is _not_ a
 valid PO file in itself.  It contains additional terminal-specific
 escape sequences or HTML tags.  A PO file reader will give a syntax
 error when confronted with such content.  Except for the ‘--color=html’
 case, you therefore normally don’t need to save output produced with the
 ‘--color’ option in a file.