10-27-2010
grep single quotes or double quotes
Unix superusers,
I am new to unix but would like to learn more about grep. I am very familiar with regular expressions as i have used them for searching text files in windows based text editors. Since I am not very familiar with Unix, I dont understand when one should use GREP with the regular expression pattern with doublequotes versus single quotes.
Can someone tell me the difference when using GREP with single or double quotes?
grep "^asdf" /testdirectory/testfile.txt
grep '^asdf' /testdirectory/testfile.txt
Thanks,
George
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LEARN ABOUT DEBIAN
bzfgrep
BZGREP(1) General Commands Manual BZGREP(1)
NAME
bzgrep, bzfgrep, bzegrep - search possibly bzip2 compressed files for a regular expression
SYNOPSIS
bzgrep [ grep_options ] [ -e ] pattern filename...
bzegrep [ egrep_options ] [ -e ] pattern filename...
bzfgrep [ fgrep_options ] [ -e ] pattern filename...
DESCRIPTION
Bzgrep is used to invoke the grep on bzip2-compressed files. All options specified are passed directly to grep. If no file is specified,
then the standard input is decompressed if necessary and fed to grep. Otherwise the given files are uncompressed if necessary and fed to
grep.
If bzgrep is invoked as bzegrep or bzfgrep then egrep or fgrep is used instead of grep. If the GREP environment variable is set, bzgrep
uses it as the grep program to be invoked. For example:
for sh: GREP=fgrep bzgrep string files
for csh: (setenv GREP fgrep; bzgrep string files)
AUTHOR
Charles Levert (charles@comm.polymtl.ca). Adapted to bzip2 by Philippe Troin <phil@fifi.org> for Debian GNU/Linux.
SEE ALSO
grep(1), egrep(1), fgrep(1), bzdiff(1), bzmore(1), bzless(1), bzip2(1)
BZGREP(1)