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Full Discussion: Grep through a variable
Top Forums Shell Programming and Scripting Grep through a variable Post 302564231 by bakunin on Thursday 13th of October 2011 06:43:28 AM
Old 10-13-2011
There are a few problems with your code:

Quote:
Originally Posted by rajesh
Code:
ADDM=`ls |grep "THERE WAS NOT ENOUGH DATABASE TIME FOR ADDM ANALYSIS" $file | awk 'BEGIN {FS=":"}{print $1}'`


First off, using backticks is deprecated, outdated, not recommended and (in an ideal world) prohibited by law. Seriously: it is only supported for backward compatibility. Don't use it. Use the "$(...)" instead.

Code:
ADDM="$(ls |grep "THERE WAS NOT ENOUGH DATABASE TIME FOR ADDM ANALYSIS" $file | awk 'BEGIN {FS=":"}{print $1}')"

Second: what is your "grep" supposed to do? As you have written it, it filters the output of "ls" and i do not think this is what is intended.

Third: you have to decide either to have "grep" work in a pipeline or over a file. You can't have both, as you have written:

Code:
grep "some_regex" /path/to/some/file   # this is ok
some_process | grep "some_regex"      # this is ok too
some_process | grep "some_regex" /some/file    # this won't work

Fourth: This doesn't need to be an error, but i suppose it might be one. Do you really want to search for some all-caps text? If so, then all is ok, otherwise you might want to use the "-i" switch (case-insensitive search mode) for grep.

Fifth: you use awk to further work on lines found. You could probably do what your "grep" does inside awk if you use it anyways, because awk can work on select lines as well.

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
rishav
 

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LEARN ABOUT CENTOS

paps

PAPS(1) 						      General Commands Manual							   PAPS(1)

NAME

       paps - UTF-8 to PostScript converter using Pango

SYNOPSIS

       paps [options] files...

DESCRIPTION

       paps reads a UTF-8 encoded file and generates a PostScript language rendering of the file. The rendering is done by creating outline curves
       through the pango ft2 backend.

OPTIONS

       These programs follow the usual GNU command line syntax, with long options starting with  two  dashes  (`-').   A  summary  of  options	is
       included below.

       --landscape
	      Landscape output. Default is portrait.

       --columns=cl
	      Number of columns output. Default is 1.

       --font=desc
	      Set the font description. Default is Monospace 12.

       --rtl  Do rtl layout.

       --paper ps
	      Choose paper size. Known paper sizes are legal, letter, a4. Default is A4.

       --bottom-margin=bm
	      Set bottom margin in postscript points (1/72 inch). Default is 36.

       --top-margin=tm
	      Set top margin. Default is 36.

       --left-margin=lm
	      Set left margin. Default is 36.

       --right-margin=rm
	      Set right margin. Default is 36.

       --help Show summary of options.

       --header
	      Draw page header for each page.

       --markup
	      Interpret the text as pango markup.

       --encoding=ENCODING
	      Assume the documentation encoding is ENCODING.

       --lpi  Set the lines per inch. This determines the line spacing.

       --cpi  Set the characters per inch. This is an alternative method of specifying the font size.

       --stretch-chars
	      Indicates  that  characters  should be stretched in the y-direction to fill up their vertical space. This is similar to the texttops
	      behaviour.

AUTHOR

       paps was written by Dov Grobgeld <dov.grobgeld@gmail.com>.

       This manual page was written by Lior Kaplan <kaplan@debian.org>, for the Debian project (but may be used by others).

								  April  17, 2006							   PAPS(1)
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