Windows CMD Line中的Perl和Regex

Question

Is there anyway to accomplish matching + storing all in one cmd line? So instead of saving the matches to an array: ie

($matches) = $filecontents =~ m/.../g

...the matches would save to a *.txt file? I have been experimenting for a couple of days now, and believe that I am close to a solution. But a few nuances of Perl and Windows CMD Prompt are preventing me from accomplishing this task. Here's what I most recently tried:

% perl -p -i.bak -e "m/(?<=")(\d\.\d+)(?=")/g" filename.extension

I am a beginner with the CMD line, and I am running Windows 7 (soon to be switching over to Linux). Obviously I need to specify a file to which I can save my matches. The trouble is, this is where my knowledge drops off. Could someone give me a hand with this? Any comments are appreciated. Thank you!

Answer 1

If I understand correctly, you want to pull out all of the matches from an entire file, and write those results to a separate file.

This will work if the below results are what you're after. I don't have a Windows box to test on, but this should work (you might have to use double quotes on the outside of the one-liner and escape the ones inside, but I'm not sure.

This one-liner iterates without printing ( -n ) the 'file.txt' file, and prints a match combined with a newline if there is one into the 'results.txt' file via command-line redirection:

perl -ne 'print "$_\n" for m/(?<=")(\d\.\d+)(?=")/g' file.txt > results.txt

Input file:

$ cat file.txt
one
two "9.162"
three one "6.3"
five one six

Output file:

$ cat results.txt
9.162
6.3