Note that a preprocessor cannot output an empty file, since that
is interpreted as meaning there is no replacement, and the origi-
nal file is used. To avoid this, if LESSOPEN starts with two ver-
tical bars, the exit status of the script becomes meaningful. If
the exit status is zero, the output is considered to be replace-
ment text, even if it empty. If the exit status is nonzero, any
output is ignored and the original file is used. For compatibil-
ity with previous versions of less, if LESSOPEN starts with only
one vertical bar, the exit status of the preprocessor is ignored.
Use two pipe symbols for zless, so that zless'ing a compressed empty
file will give output rather than being interpreted as its compressed
form, which is typically a binary.
Thanks Mark Nudelman for pointing out this difference and the
suggested solution.
Reported by: Matthias Meyser <meyser xenet.de>
PR: bin/168839
MFC after: 2 weeks
Major changes from v429:
* Don't pass "-" to non-pipe LESSOPEN unless it starts with "-".
* Allow a fraction as the argument to the -# (--shift) option.
* Fix highlight bug when underlined/overstruck text matches at end of line.
* Fix non-regex searches with ctrl-R.
Approved by: re (kensmith, kib)
extensions. This seems to be unnecessary and prevents less(1) from being
able to detect file changes, so remove the part.
Submitted by: Eric Huss <e-huss netmeridian com>
PR: bin/102624
Discussed with: des
MFC After: 3 days
similar to the zmore script that comes with gzip (and in fact, in most
Linux distros, zless is a symlink to that very same zmore script) but has
the advantage that you get the correct file name on the less status line,
and can use :n and :p to navigate back and forth between multiple files.
MFC after: 1 week
cat ${.ALLSRC} > ${.TARGET}
rather than
ln -sf ${.ALLSRC} ${.TARGET}
not to depends on absolute-path of symbolic links.
Commented by: marcel, obrien, bde
