Shell Programming and Scripting

Hi all,

I'm having an issue about a code i should write...
I have a file... with the following numbers in regex format:

$ cat file_regex.txt

Code:

555005080[78]07[0-9]*
55500218200[35][0-9]* 
182936[01][0-9]* 
182929[78][0-9]* 
4179[012356789][0-9]* 
381[23][89][0-9]* 
550069341[0-9]*

So this is a file cointaing some regex... so for each regex i need to create a number which is compatible to this regex... for example:

This:

Code:

555005080[78]07[0-9]*

Should transform into:

Code:

5550050807070

So what i need to do... is whenever is this file when there's some number into [], i need to remove this tags and get the first occurrence inside the brackets... so my outfile file will look like this:

$ cat output_file.txt

Code:

5550050807070
5550021820030 
18293600 
18292970 
417900 
381280 
5500693410

Any good ideas of how doing it?
I thought doing some thing with cut... but the way i thought... code will be very ugly, disgusting and not performative lol

Thanks

Code:

perl -pe 's/\[(\d)[^\]]*\]\*?/\1/g' file_regex.txt > output_file.txt

Code:

sed 's/\[\([0-9]\)[^]]*\][*?]*/\1/g' file_regex.txt > output_file.txt

Wow! Thanks... both solutions just worked fine!