pattern substuitution idea solution required.

[rao12]

Hi,
I have a set of files and i need to substitute an existing pattern with a new one.
I have used sed to do the simple substitution.
sed -e 's/Old/New/g' file_name > new_file
But it is case sensitive. I have a set of files which are having a different case for the pattern.
Can anyone let me know how to go aboutt so that i can substitute even if the old pattern is in a different case.

Thanks
Rao

 

[CaKiwi]

You could try this.

sed -e 's/[Oo][Ll][Dd]/New/g' file_name > new_file

This will replace old spelled with any combination of upper and lower case letters with New. If there is a better way, I'm sure someone will tell us.

Hope this helps.

CaKiwi

 

[Krunek]

Hi rao!

If you wish to use gawk (GNU's version of awk; GNU, thanks! God bless you!), you can try this:

gawk -v IGNORECASE=1  '{ gsub(/old/,"new"); print }' file_name > new_file

When gawk's built-in variable IGNORECASE is true, gawk ignores case of all regular expressions. Function gsub is gawk's general substitution function.

Bye!

KP.