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LESSPIPE.SH(1)			 User Commands			LESSPIPE.SH(1)

NAME - a filter for less


       Usually is called as an input filter to less With the help
       of that filter less will	display	 the  uncompressed  contents  of  com-
       pressed	(gzip,	bzip2,	compress, rar, 7-zip, lzip, xz or lzma)	files.
       For files containing archives and directories, a	table of contents will
       be  displayed  (e.g tar,	ar, rar, jar, rpm and deb formats). Other sup-
       ported formats include nroff, pdf, ps, dvi, shared  library,  MS	 word,
       OASIS  (e.g.  Openoffice), NetCDF, html,	mp3, jpg, png, iso images, Ma-
       cOSX bom, plist and archive formats, perl storable  data	 and  gpg  en-
       crypted	files.	This does require additional helper programs being in-

       If at configure time support for	the  ENV  variable  LESS_ADVANCED_PRE-
       PROCESSOR  was included then files with mostly ASCII text such as html,
       ps, rtf and files with alternate	character encoding remain normally un-
       processed (see below)

       The  filter does	not only display the above mentioned file formats, but
       can also	be applied recursively up to a depth of	6 where	applying a de-
       compression algorithm counts as a separate level.

       In  a  few  rare	 cases the file	command	does not recognize the correct
       format (especially with nroff).	In such	cases filtering	 can  be  sup-
       pressed by a trailing colon on the file name.

       If  the	file command reports text with UTF-8, ISO-8859-1 or UTF-16 en-
       coded characters	then the text will be transformed using	iconv into the
       default	encoding.  This	 does assume iconv has the right default which
       can be wrong in some situations.

       To suppress informal messages in	the first line of  the	filter	output
       the ENV variable	LESSQUIET can be set to	a nonempty value.

       The  filter  is	called	from  less  provided  the environment variable
       LESSOPEN	is set properly. For the shells	csh and	tcsh the command

       setenv LESSOPEN "| %s"

       should be used, for other shells	the command

       LESSOPEN="| %s"; export LESSOPEN

       does activate the filter	for less. Use the  fully  qualified  path,  if  is not in the search path. The command to set LESSOPEN can
       also be displayed by calling	without	 arguments.  This  can
       even be used to set LESSOPEN directly:

       eval ``

       Having  set the environment variable as described above,	less will then
       display textual information for a wide range of file formats.

       This version of allows you to view  individual  files  con-
       tained in a file	archive, which itself may even be contained in another

       The notation for	viewing	files in multifile archives is

       less archive_file:contained_file

       or even

       less super_archive:archive_file:contained_file

       To display a file in raw	format,	a colon	(:) has	to be appended to  the
       file  name.   To	suppress the decompression of files two	colons have to
       be appended. This does apply as well to the last	file in	the colon sep-
       arated chain of file names as described above.

       To display files	without	engaging temporarily, the command

       cat filename | less

       can be used instead of unsetting	the environment	variable LESSOPEN

       If   the	  ENV  variable	 LESS_ADVANCED_PREPROCESSOR  is	 respected  by then	files containing mostly	ASCII text get	displayed  un-
       modified.  To  activate	filtering  for	such  formats  the contents of
       LESS_ADVANCED_PREPROCESSOR has to be set	to an non empty	value.

       The filter is able to do	syntax highlighting  for  the  languages  ada,
       asm,  awk,  c, c++, groff, html,	xml, java, javascript, lisp, m4, make,
       pascal, patch, perl, povray, python, ruby shellscript and sql by	 using
       code2color  as  the  colorizing	program.  A different colorizer	can be
       called within code2color	by setting the ENV variable  LESSCOLORIZER  to
       the  name of an alternative (currently only pygmentize allowed).	There-
       fore code2color is always needed	for syntax highlighting.

       ATTENTION: Syntax highlighting is only activated,  if  the  environment
       variable	LESS exists and	contains the option -R or -r or	less is	called
       with one	of these options. This guarantees, that	instead	of literal es-
       cape  sequences,	colors are displayed. The detection of the -r/-R pres-
       ence at runtime is rather dependent on the operating system and may not
       work in all cases.  Putting the option in the LESS environment variable
       is guaranteed to	work.

       As syntax highlighting is rather	resource intense, it can  be  switched
       off  by appending a colon after the file	name, if the output was	color-
       ful. If the wrong language was chosen for syntax	highlighting, then an-
       other  one  can be forced by appending a	colon and a suffix to the file

       The following suffixes are recognized (works with code2color only):

       .ada .asm .inc .awk .c .h .cpp .cxx .groff .html	.php  .xml  .java  .js
       .lsp .m4	Makefile .pas .patch .diff .pm .pl .pod	.pov .py .rb .sh .sql

       When  the conditions for	syntax highlighting are	met directory listings
       and listings of tar file	contents get colorized as well.

       Written by Wolfgang Friebel

       Report bugs to <Wolfgang.Friebel	AT>.

       Copyright (C) 2005-2015 Wolfgang	Friebel
       This is free software; see the source for copying conditions.  There is
       NO  warranty;  not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR


       A description of is also contained in the file README  con-
       tained in the source code package			   Oct 2011			LESSPIPE.SH(1)


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