grep first occurrence but continue to next entry in patternfile Post: 302528659

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Top Forums UNIX for Dummies Questions & Answers grep first occurrence but continue to next entry in patternfile Post 302528659 by newhavendweeb on Tuesday 7th of June 2011 03:52:32 PM

06-07-2011

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grep first occurrence but continue to next entry in patternfile

I have 1300 files (SearchFiles0001.txt, SearchFiles0002.txt, etc.) , each with 650,000 lines, tab-delimited data.

I have a pattern file, with about 1000 lines with a single word. Each single word is found in the 1300 files once.

If I grep -f PatternFile.txt SearchFiles*.txt >OutputFile.txt
the search takes forever, because it searches 650,000 lines x 1300 files for each of the 1000 words.

If I grep -f PatternFile.txt -m 1 SearchFiles*.txt >OutputFile.txt
the search stops after the first line of PatternFile.txt, and I get an OutputFile.txt with 1300 lines: the first entry of PatternFile.txt, but none of the other 999.

How do I make the search faster (by finding the first occurrence of my search parameter, and then moving on to the next search parameter in PatternFile.txt)?

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LEARN ABOUT X11R4

zgrep

ZGREP(1)                                                      General Commands Manual                                                     ZGREP(1)

NAME

       zgrep - search possibly compressed files for a regular expression

SYNOPSIS

       zgrep [ grep_options ] [ -e ] pattern filename...

DESCRIPTION

       Zgrep  invokes  grep  on  compressed  or  gzipped  files.   These  grep  options  will  cause  zgrep  to  terminate  with  an  error  code:
       (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*).  All other 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 the GREP environment variable is set, zgrep uses it as the grep program to be invoked.

EXIT CODE

       2 - An option that is not supported was specified.

AUTHOR

       Charles Levert (charles@comm.polymtl.ca)

SEE ALSO

       grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1)

                                                                                                                                          ZGREP(1)