Attempts to compare two compressed files result in no output and
exit status 2.
Instead of going to standard output, ‘diff’ output is being
captured in the xz_status variable along with the exit status from
the decompression commands. Later, when this variable is examined
for nonzero status codes, numerals from dates in the ‘diff’ output
make it appear as though decompression failed.
So let the ‘diff’ output leak to standard output with another file
descriptor. (This trick is used in all similar contexts elsewhere
in xzdiff and in the analogous context in gzip’s zdiff script.)
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.