[PATCH] Use POSIX standardized options for head(1) and tail(1)
Mark D. Baushke
mdb at juniper.net
Sun Apr 26 18:24:56 AEST 2020
Michael Forney <mforney at mforney.org> writes:
> Indeed, that's what motivated the patch. The version of tail on my
> system does not support the legacy options.
I suspected as much. Which system are you using?
> Another possibility is `sed 2q`, which works for any number. It's even
> mentioned in the rationale section as a way to simulate head(1).
Yes, "sed 2q" should also work fine on all versions of sed I have ever
> > tail +3 == tail -n +3 == sed '1,2d'
This may also be written as "sed -n '3,$p'" if you want to just print
the lines you want rather than deleting the lines you do not want.
> I think this script is only necessary to rebuild the .depend file,
> which is not usually necessary, but you make a good point. I didn't
> realize that some implementations did not support the -n option. The
> change you suggested sounds good to me.
Most of those systems that do not support POSIX head and tail are very
ancient... I just no longer recall which ones they were... It has been a
long time since I have seen one, but I would rather not see it break if
there is a way to be compatible for all other systems.
Be safe, stay healthy,
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