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Diffstat (limited to 'upstream/debian-unstable/man1/lesspipe.1')
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diff --git a/upstream/debian-unstable/man1/lesspipe.1 b/upstream/debian-unstable/man1/lesspipe.1 new file mode 100644 index 00000000..8e842ef4 --- /dev/null +++ b/upstream/debian-unstable/man1/lesspipe.1 @@ -0,0 +1,156 @@ +.TH LESSOPEN 1 +.\" NAME should be all caps, SECTION should be 1-8, maybe w/ subsection +.\" other parms are allowed: see man(7), man(1) +.SH NAME +lessfile, lesspipe \- "input preprocessor" for less. +.SH SYNOPSIS +.B lessfile, lesspipe +.SH "DESCRIPTION" +This manual page documents briefly the +.IR lessfile , +and +.I lesspipe +commands. +This manual page was written for the Debian GNU/Linux distribution +because the input preprocessor scripts are provided by Debian GNU/Linux and +are not part of the original program. +.PP +.I lessfile +and +.I lesspipe +are programs that can be used to modify the way the contents of a file are +displayed in +.I less. +What this means is that +.I less +can automatically open +up tar files, uncompress gzipped files, and even display something reasonable +for graphics files. +.PP +.I lesspipe +will toss the contents/info on STDOUT and +.I less +will read them +as they come across. This means that you do not have to wait for the +decoding to finish before less shows you the file. This also means that +you will get a 'byte N' instead of an N% as your file position. You can +seek to the end and back to get the N% but that means you have to wait +for the pipe to finish. +.PP +.I lessfile +will toss the contents/info on a file which +.I less +will then +read. After you are done, +.I lessfile +will then delete the file. This means that the process has to finish before +you see it, but you get nice percentages (N%) up front. +. +.SH USAGE +Just put one of the following two commands in your login script (e.g. +~/.bash_profile): +.PP + eval "$(lessfile)" +.PP +or +.PP + eval "$(lesspipe)" +.SH FILE TYPE RECOGNITION +File types are recognized by their extensions. +This is a list of currently supported extensions +(grouped by the programs that handle them): + +.DS + *.a + *.arj + *.tar.bz2 + *.bz + *.bz2 + *.deb, *.udeb, *.ddeb + *.doc + *.egg + *.gif, *.jpeg, *.jpg, *.pcd, *.png, *.tga, *.tiff, *.tif + *.iso, *.raw, *.bin + *.lha, *.lzh + *.tar.lz, *.tlz + *.lz + *.7z + *.pdf + *.rar, *.r[0-9][0-9] + *.rpm + *.tar.gz, *.tgz, *.tar.z, *.tar.dz + *.gz, *.z, *.dz + *.tar + *.tar.xz, *.xz + *.whl + *.jar, *.war, *.xpi, *.zip + *.zoo + *.tar.zst, *.tzst + *.zst +.DE +.SH USER DEFINED FILTERS +It is possible to extend and overwrite the default +.I lesspipe +and +.I lessfile +input processor if you have specialized requirements. Create an executable +program with the name +.I .lessfilter +and put it into your home directory. This can be a shell script or a binary +program. + +.PP +It is important that this program returns the correct exit code: return 0 if +your filter handles the input, return 1 if the standard +.I lesspipe/lessfile +filter should handle the input. + +.PP +Here is an example script: + +.DS + #!/bin/sh + + case "$1" in + *.extension) + extension-handler "$1" + ;; + *) + # We don't handle this format. + exit 1 + esac + + # No further processing by lesspipe necessary + exit 0 +.DE + +.SH FILES +.TP +.I ~/.lessfilter +Executable file that can do user defined processing. See section USER DEFINED +FILTERS for more information. +.SH BUGS +.PP +Sometimes, less does not display the contents file you want to view but output +that is produced by your login scripts (~/.bashrc or ~/.bash_profile). This +happens because less uses your current shell to run the lesspipe filter. Bash +first looks for the variable $BASH_ENV in the environment expands its value +and uses the expanded value as the name of a file to read and execute. If +this file produces any output less will display this. A way to solve this +problem is to put the following lines on the top of your login script that +produces output: + +.DS + if [ -z "$PS1" ]; then + exit + fi +.DE + +This tests whether the prompt variable $PS1 is set and if it isn't (which is +the case for non-interactive shells) it will exit the script. +.SH "SEE ALSO" +less(1) +.SH AUTHOR +This manual page was written by Thomas Schoepf <schoepf@debian.org>, +for the Debian GNU/Linux system (but may be used by others). Most of the +text was copied from a description written by Darren Stalder <torin@daft.com>. |