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Old 05-13-2008
era era is offline Forum Advisor  
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Join Date: Mar 2008
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Posts: 3,652
If your grep can read patterns from a file (like GNU grep), try something like this.

Code:
cut -c1-5 file2 >patterns
grep -f patterns file1 >matches
grep -f patterns -v file1 >nonmatches
There is some room for improvement, relating to making the patterns always match at beginning of line, etc. You could replace the first line with something like

Code:
sed 's/^\(.....\).*/^"\1",/' file2 >patterns
This adds the double quotes around the search string and adds a comma behind it and the special character "^" before it, which means match only at beginning of line.

Last edited by era; 05-13-2008 at 03:28 AM.. Reason: Explain revised patterns