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Top Forums Shell Programming and Scripting grep/awk on a single column in a for loop Post 302476469 by Corona688 on Wednesday 1st of December 2010 05:51:39 PM
Old 12-01-2010
What problem do you get? Be specific.

"for x in `stuff`" is a useless use of backticks, wasteful, and also dangerous because strings in a shell often have a maximum size. Whenever you have that you can do it more safely and more efficiently like:

Code:
awk '...' | while read VALUE
do
        
done

...but you don't even need a loop. You can just feed one instance of awk into another with awk '{...}' | awk '{...}' ...but the best option would probably be to do it all in one instance of awk. It's a powerful enough language.
 

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IGAWK(1)							 Utility Commands							  IGAWK(1)

NAME
igawk - gawk with include files SYNOPSIS
igawk [ all gawk options ] -f program-file [ -- ] file ... igawk [ all gawk options ] [ -- ] program-text file ... DESCRIPTION
Igawk is a simple shell script that adds the ability to have ``include files'' to gawk(1). AWK programs for igawk are the same as for gawk, except that, in addition, you may have lines like @include getopt.awk in your program to include the file getopt.awk from either the current directory or one of the other directories in the search path. OPTIONS
See gawk(1) for a full description of the AWK language and the options that gawk supports. EXAMPLES
cat << EOF > test.awk @include getopt.awk BEGIN { while (getopt(ARGC, ARGV, "am:q") != -1) ... } EOF igawk -f test.awk SEE ALSO
gawk(1) Effective AWK Programming, Edition 1.0, published by the Free Software Foundation, 1995. AUTHOR
Arnold Robbins (arnold@skeeve.com). ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +--------------------+-----------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +--------------------+-----------------+ |Availability | SUNWgawk | +--------------------+-----------------+ |Interface Stability | Volatile | +--------------------+-----------------+ NOTES
Source for gawk is available on http://opensolaris.org. Free Software Foundation Nov 3 1999 IGAWK(1)
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