02-12-2008
Quote:
Originally Posted by
hidnana
We have an egrep search in a while loop.
egrep -w "$key" ${PICKUP_DIR}/new_update >> ${PICKUP_DIR}/update_record_new
${PICKUP_DIR}/new_update is 210 MB file
In each iteration, the egrep on an average takes around 50-60 seconds to search. Ther'es nothing significant in the loop other than egrep. And when we checked the timestamps, egrep is what slowing it down.
Is it possible to improve egrep's performance ? Or do we need to use perl or any other pattern search ?
Could you please help ?
Does the value of "key" and "PICKUP_DIR" change with each iteration ?
Look into the -f flag of grep.
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LEARN ABOUT CENTOS
lzfgrep
XZGREP(1) XZ Utils XZGREP(1)
NAME
xzgrep - search compressed files for a regular expression
SYNOPSIS
xzgrep [grep_options] [-e] pattern file...
xzegrep ...
xzfgrep ...
lzgrep ...
lzegrep ...
lzfgrep ...
DESCRIPTION
xzgrep invokes grep(1) on files which may be either uncompressed or compressed with xz(1), lzma(1), gzip(1), bzip2(1), or lzop(1). All
options specified are passed directly to grep(1).
If no file is specified, then standard input is decompressed if necessary and fed to grep(1). When reading from standard input, gzip(1),
bzip2(1), and lzop(1) compressed files are not supported.
If xzgrep is invoked as xzegrep or xzfgrep then egrep(1) or fgrep(1) is used instead of grep(1). The same applies to names lzgrep, lze-
grep, and lzfgrep, which are provided for backward compatibility with LZMA Utils.
ENVIRONMENT
GREP If the GREP environment variable is set, xzgrep uses it instead of grep(1), egrep(1), or fgrep(1).
SEE ALSO
grep(1), xz(1), gzip(1), bzip2(1), lzop(1), zgrep(1)
Tukaani 2011-03-19 XZGREP(1)