tag 23227 notabug thanks On 04/05/2016 03:55 PM, Santiago Ruano Rincón wrote: > Hi, > > grep fails to parse the tilde (~) to represent $HOME, when it is used to > give a file's path to --file=, but it works with --file
That's not grep's fault, but the shell's.
> % echo "hola" | LANG=C grep --file ~/tmp-pattern
> hola
> % echo "hola" | LANG=C grep --file=${HOME}/tmp-pattern
> hola
Try this to see that it is the shell:
$ echo testing --file ~/tmp-pattern
testing --file /home/eblake/tmp-pattern
$ echo testing --file=~/tmp-pattern
testing --file=~/tmp-pattern
$ echo testing --file=$HOME/tmp-pattern
testing --file=/home/eblake/tmp-pattern
Tilde expansion in the shell is defined by POSIX to only happen if ~
occurs as the first character of a word (or, in special cases such as
"export foo=~/bar" where a shell builtin is consuming its operands in
assignment context - but this is not one of those special cases). IN
other words, for ALL other uses where you are passing '--option=value',
tilde expansion does NOT happen in 'value'; and you are correct that
using '--option value' as two separate arguments (for all long options
where the argument is not optional) is the easiest way to get ~ to the
front of the word and thus have tilde expansion again.
Since this behavior is baked into your shell, there's nothing grep can
do about it, so I'm closing this as not a bug.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
