[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#39678: 'grep --ignore-case --color' does not always color the matche
bug#39678: 'grep --ignore-case --color' does not always color the matches
Wed, 19 Feb 2020 11:18:18 +0100
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1
echo a | grep -i --color '\a'
echo a | grep -i --color '\A'
Of the above two commands, only the second colorizes the printed "a".
(An old GNU grep on NetBSD (grep 2.5.1a nb1) does the opposite of
a modern grep: it will show color for \a, but none for \A.)
Bug was found in GNU grep 3.1 while checking whether it understands
\d as a shorthand for [0-9]. Still present in 3.4. The locale does
not appear to matter.
In a report against glibc  that seems to be related, a comment
says that "Unknown backslash escapes invoke undefined behaviour."
But where in the documentation does it say so?
When searching for a regular expression in GNU nano (^W M-R), nano says
it cannot find any \a. But for \A, it will find all "a"s and "A"s.
Nano's default search is case insensitive. See  for the original
report by Ben Addis. I suppose this is the same or a related bug in
the regex module of gnulib, which nano uses.
Description: OpenPGP digital signature
|[Prev in Thread]
||[Next in Thread]|
- bug#39678: 'grep --ignore-case --color' does not always color the matches,
Benno Schulenberg <=