It can be somewhat confusing that
less < some_file.txt
works fine, whereas
xzless < some_file.txt.xz
does not. Since version 429, ‘less’ allows a filter specified in
the LESSOPEN environment variable to preprocess its input even if
it comes from standard input, if $LESSOPEN begins with ‘|-’. So
set $LESSOPEN to take advantage of this feature.
Check less’s version at runtime so xzless can continue to work
with older versions.
the latest versions found from gzip CVS repository.
configure will try to find a POSIX shell to be used by
the scripts. This should ease portability on systems
which have pre-POSIX /bin/sh.
xzgrep and xzdiff support .xz, .lzma, .gz, and .bz2 files.
xzmore and xzless support only .xz and .lzma files.
The name of the xz executable used in these scripts is
now correct even if --program-transform-name has been used.
Jonathan Nieder
Lasse Collin