It could be done pretty simply with a one-liner if I understand the issue correctly (untested): 

perl -pi.bak -e "s/(SW_V)[\d.]+/${1}02.05/" filename.txt

[download]

For the record, the -i switch handles "in-place editing", but it does so in a way that is pretty safe. It actually writes a new outfile, and then renames the input file to whatever.bak, and then renames the output file to the name of the old input file. If you wanted to do it by hand (ie, not as a one liner, and not using the -i switch), you would probably just open the input file and the output file and later use rename to handle the filename swap. ...seems superior to a read/write filehandle.

Another potential solution is to use Tie::File, and then just wend your way through the array, performing the substitution when the version string is encountered. Tie::File handles the dirty details of in-place editing for you.


Dave

In reply to Re: Modifying File Contents by davido
in thread Modifying File Contents by ramthen

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