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Deleting lines in a fixed length file where there is a word at specific location

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# 1  
Old 09-11-2013
Question Deleting lines in a fixed length file where there is a word at specific location
I have a big file having 100 K lines.

I have to read each line and see at 356 character position whethere there is a word "W" in it. If it is their then don't delete the line otherwise delete it.

There are two lines as one Header and one trailer which should remain same.

Can somebody help on how to achieve by ksh script or any other way
# 2  
Old 09-11-2013
It you mean character "W" at position 356 try:
Code:
awk 'NR<3; {l=$0; if (substr(l,356,1)=="W") print } END {print l}' infile > outfile

This User Gave Thanks to rdrtx1 For This Post:
mohit kanoongo
# 3  
Old 09-11-2013
Question It worked
Great it worked.

But somehow the top most line was not included by this command. Any reasons why.

For ex:

Topmost is Header line
Second was the body line but it remains there even if at 356 character it is "1" instead of "W"

Can you please helpSmilie
# 4  
Old 09-11-2013
Quote:
Originally Posted by mohit kanoongo
Great it worked.

But somehow the top most line was not included by this command. Any reasons why.

For ex:

Topmost is Header line
Second was the body line but it remains there even if at 356 character it is "1" instead of "W"

Can you please helpSmilie
In your 1st message in this thread, you said:
Quote:
There are two lines as one Header and one trailer which should remain same.
rdrtx1 and I both understood this to mean that there were two header ilnes and one trailer line. If there is just one header line, change NR<3; in rdtx1's script to NR<2; or NR==1;.

If you are trying this on a Solaris/SunOS system, use /usr/xpg4/bin/awk, /usr/xpg6/bin/awk, on nawk instead of awk.
# 5  
Old 09-11-2013
If $0 is still defined in the END section (which is not necessarily true for all awk implementations), you can try
Code:
awk 'FNR==1; substr($0,356,1)=="W"; END{print}' file

# 6  
Old 09-11-2013
This should with all awk versions
Code:
awk '(NR==1 || substr($0,356,1)=="W"); {l=$0} END{print l}' file

Last edited by MadeInGermany; 09-11-2013 at 10:26 PM.. Reason: bug fix
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