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replacing specific lines in a file


 
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# 1  
Old 09-29-2006
replacing specific lines in a file

Hi there
I have a file which has the lines


Code:
# Serial number for hostid
EXP_SERIAL_=""

These lines could be anywhere in the file as far as line numbers go, I would like replace these two lines with

Code:
# Serial number for hostid $var1
EXP_SERIAL_$var1="$var2"

Is there a quick and simple way for me to do this ?

cheers
# 2  
Old 09-29-2006
........................................

Last edited by gauravgoel; 09-29-2006 at 08:58 AM.. Reason: wrong solution
# 3  
Old 09-29-2006
use this
Quote:
sed "s/old text/new text/g" input.txt
though not clean, should work

Last edited by gauravgoel; 09-29-2006 at 09:10 AM..
# 4  
Old 09-29-2006
thats great but if i run that command from the command line it outputs the correct result to the screen but doesnt actually edit the file


How do i get it to make a permanent change to the file ??
# 5  
Old 09-29-2006
Code:
sed "s/old text/new text/g" input.txt > temp
mv temp input.txt

or

Code:
perl -pi -e "s/old text/new text/g" input.txt

# 6  
Old 09-29-2006
that works great thankyou ....I wanted to avoid creating a new file and mv'ing it back over again....but if i have to do that then so be it

thanks for your help
# 7  
Old 09-30-2006
You might try something like this if you don't want to create a file:
Code:
echo '%s/oldtext/newtext/g\nwq' | ex file

This will edit the text within the file. Non interactive style vi. The exact syntax for ex is a bit murky I can't find a lot of docs on it, but in a few occasions it's well worth figuring out and using.

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