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Top Forums Shell Programming and Scripting Re: Deleting lines from big file. Post 302491009 by wpeckham on Wednesday 26th of January 2011 11:48:34 AM
Old 01-26-2011
big file

1. Always check that you are using the correct tools. Sed is a stream editor, and is wonderful for making on-the-fly edits. What you want, though, is to select or deselect lines to retain. Finding and filtering lines this way is a 'grep' kinda thing. Used in the form 'fgrep' it finds strings, rather then regular expressions, and is a tool better suited to your purpose.
2. Perl is also capable, but may be overkill for what you want to do.
3. AWK could be made to do the same job, but would be awkward compared to grep. (pun intended: sorry)
 

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GZGREP(1)						      General Commands Manual							 GZGREP(1)

NAME
gzgrep, gzegrep, gzfgrep - search possibly compressed files for a regular expression SYNOPSIS
gzgrep [ grep_options ] [ -e ] pattern filename... DESCRIPTION
gzgrep is used to invoke the grep on compress'ed or gzip'ed files. All options specified are passed directly to grep. If no file is speci- fied, 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 gzgrep is invoked as gzegrep or gzfgrep then egrep or fgrep is used instead of grep. If the GREP environment variable is set, gzgrep uses it as the grep program to be invoked. For example: for sh: GREP=fgrep gzgrep string files for csh: (setenv GREP fgrep; gzgrep string files) AUTHOR
Charles Levert (charles@comm.polymtl.ca) SEE ALSO
grep(1), egrep(1), fgrep(1), gzdiff(1), gzmore(1), gznew(1), gzforce(1), gzip(1), gzexe(1) ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +--------------------+-----------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +--------------------+-----------------+ |Availability | SUNWgzip | +--------------------+-----------------+ |Interface Stability | External | +--------------------+-----------------+ NOTES
Source for gzip is available in the SUNWgzipS package. GZGREP(1)
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