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grep bug with -P -o option
From: |
fd |
Subject: |
grep bug with -P -o option |
Date: |
Wed, 14 Jul 2010 19:43:31 -0700 (PDT) |
User-agent: |
G2/1.0 |
Dear all
I'm a novice in this Linux business, but I think there's something not
right. When I try to search using a perl regular expression, so if a
do:
gcc --help | grep -P '(?<=the )'
I get all lines for which there is any text preceded by "the "
-dumpspecs Display all of the built in spec strings
-dumpversion Display the version of the compiler
-dumpmachine Display the compiler's target processor
-print-search-dirs Display the directories in the compiler's
search path
-print-libgcc-file-name Display the name of the compiler's
companion library
-print-file-name=<lib> Display the full path to library <lib>
-print-prog-name=<prog> Display the full path to compiler component
<prog>
-print-multi-directory Display the root directory for versions of
libgcc
-print-multi-lib Display the mapping between command line
options and
...
If I introduce the -o option so that I have only the part of each line
that matches a pattern I have no result
gcc --help | grep -P -o '(?<=the )'
Is this a bug, or am I doing something wrong.
Thanks for any help
- grep bug with -P -o option,
fd <=