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Using sed (or awk or perl) to delete rows in a file

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# 1  
Old 08-24-2011
Using sed (or awk or perl) to delete rows in a file
I have a Unix file with 200,000 records, and need to remove all records from the file that have the character ‘I' in position 68 (68 bytes from the left). I have searched for similar problems and it appears that it would be possible with sed, awk or perl but I do not know enough about any of these commands to come up with the syntax needed to do what I need to. Any help would be appreciated.
# 2  
Old 08-24-2011
Try:
Code:
perl -ne 'print if ! /^.{67}I/' infile > outfile

# 3  
Old 08-24-2011
Code:
awk -v FS="" -v OFS="" '$68 != "I"' < infile > outfile

# 4  
Old 08-24-2011
You could also do in-place editing with Perl:

Code:
perl -pi.bak -e 's/^.*\n$// if substr($_,67,1) eq "I"' your_file

The ".bak" extension after the "i" switch instructs perl to create a backup file called your_file.bak before it starts editing.

tyler_durden
# 5  
Old 08-24-2011
How about sed...
Code:
sed '/^.\{67\}I/d' file

Last edited by shamrock; 08-24-2011 at 11:37 PM..
# 6  
Old 08-24-2011
Quote:
Originally Posted by shamrock
How about sed...
Code:
sed '/.\{67\}I.*/d' file

That needs to be anchored to the beginning of the line or it could match an "I" that is not the 68th character.

Regards,
Alister
This User Gave Thanks to alister For This Post:
shamrock
# 7  
Old 08-25-2011
Thanks!
I like choices. I will give these a try. I appreciate the help.
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