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File editing with out creating a new file

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Top Forums Shell Programming and Scripting File editing with out creating a new file
# 1  
Old 11-03-2012
IBM File editing with out creating a new file
I need edit some characters in a file, but without creating intermediatory file and also one liner.

I tried:

Code:
cat foo.txt | sed '/s/abc//g' > foo.txt
cat foo.txt | sed '/s/abc//g' >> foo.txt

First one is making foo.txt to zero byte, while second one is appending my desired output to existing content.

Actually I done have -i option in sed.

Any otherway to implement this ?

Thanks!
# 2  
Old 11-03-2012
Code:
perl -i -pe 's/abc//g' foo.txt

# 3  
Old 11-03-2012
karumudi7, that is useless use of cat. sed is capable of reading the file by itself.

Another way of doing it (without -i option):-
Code:
sed -e 's/abc//g' foo.txt > foo.tmp && mv foo.tmp foo.txt

Using ed:-
Code:
printf "%s\n" '1,$s/abc//g' w q | ed foo.txt

Last edited by Yoda; 11-03-2012 at 01:01 PM..
# 4  
Old 11-03-2012
File editing with out creating a new file
Code:
sed -i 's/this/that/g' foo

will do it
Last edited by Franklin52; 11-05-2012 at 03:13 AM.. Reason: Please use code tags for data and code samples
# 5  
Old 11-03-2012
@grizzledtop: he already said in his first post that his sed doesn't have the "-i" flag. Only GNUs "sed" has this so its usage is strongly discouraged if you want to write portable scripts.

You might want to read this to understand why it is impossible.

I hope this helps.

bakunin
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