Regex conditional

Question

In my code file I have several lines asT V= X T(A); And I want the text after = to be replaced as X(T,A) with some help I got this pattern s/X\s+([^\(]*)\(/X(\1,/g; for find and replace it works great but the problem is when we have no args to pass for T Ex.T V= X T(); then after replacement it will be like X(T,) (see the extra comma) I knew it's because of /X(\1, can somebody help me rid of that extra comma, Sadly I am no regex guy.

Is there any sort of conditional we could have to say if the () is empty then do X(\1/g rather than /X(\1,/g

Answer 1

Something like this ought to do it, if you run it on the file(s) after having run the first substitution that introduces the error:

sed 's/X(\([^,]*\),)/X(\1)/g'

It will substitute X(<something-not-a-comma>,) with X(<something-not-a-comma>).

To do both substitutions in one go:

sed -e 'the first substitution' -e 'the second substitution'

Answer 2

@Kusalananda Looks like he is using Extended regex without -E option in his first substitution command in

sed -e 's/X\s+([^\(]*)\(/X(\1,/g' -e 's/X(\([^,]*\),)/X(\1)/g' ./file

But the second command looks fine. Making everything in extended Regex, this will work

sed -Ee 's/X\s+([^\(]*)\(/X(\1,/g;s/X\(([^,]*),\)/X(\1)/g' ./file