Shell Programming and Scripting

So far we have onlly been doing substitutions. Adding if-then-else logic would require a quite different script. Maybe you could rephrase this using different rules? Like if A is typedef then remove A? That would still be easy to squeeze in.

Code:

perl -0777 -pe 's/(?:typedef\s+)?struct(\s*\{.*?\})\s*(\S*);/struct \2\1;/sg'

The (?:...) is just like a regular set of parentheses, except any match is not assigned to \1 or \2, so I didn't have to change the rest of the script. And the trailing ? says the whole thing is optional.

I was confused about putting the struct inside the parens, it needs to go before \2 so I'm keeping it separate after all.

Or you could post-process the output if you can tell after the fact which ones are wrong.

Sorry, I wasn't reading properly. This is a quite separate case so you can create a different program for that.

Code:

perl -0777 -pe 's/(struct\s+\S+\s*\{.*?\})(\s*\S*);/\1;/sg'

That will remove B if you have a "struct A { ... } B' and not touch any others -- it only substitutes if there is a "struct A" part.