Re: Modifying File Contents

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

Comment on Re: Modifying File Contents Download Code

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Re^2: Modifying File Contents by johngg (Canon) on Mar 18, 2006 at 12:19 UTC
I think you could make the solution more general by incrementing what you find in the pattern although this would break if the major version changed or they got to SW_V02.100. `perl -pi.bak -e 's/(SW_V02\.)(\d\d)/$1 . sprintf("%02d", $2 + 1)/e;' f +ilename.txt` [download] You may need to change my quotes if not working on Unix. Cheers, JohnGG	[reply] [d/l]
Re^2: Modifying File Contents by ayrnieu (Beadle) on Mar 19, 2006 at 05:47 UTC
A neater regex: `s/(?<=SW_V)[\d.]+/02.05/`	[reply] [d/l]