Question

I am new to regular expressions. I am looking for something that can help me do a find and replace throughout our entire code tree with any function that creates a file descriptor.

For example, I need to change socket(PF_LOCAL,SOCK_STREAM, 0) to socket(PF_LOCAL,SOCK_STREAM | SOCK_CLOEXEC, 0)

In each case I am appending to the end of the second argument, but I do not know how long the current second argument is going to be or what text it will contain. I am thinking the best way to do it is to find the second comma and replace that with my string (" | SOCK_CLOEXEC,")

If someone could give me and example of this it would be extremely helpful. Thanks

Answer 1

I’m not totally sure if this is what you’re looking for but in perl:

s/socket\(([^,]+),([^,]+),([^,]+)\)/socket($1,$2 | SOCK_CLOEXEC,$3)/

Which means:

s/to_substitute/substitution_string/ “Find pattern to_substitute and replace it with substitution_string“

And I used:

[^,]+ which means “string without comma”.

() which are used to capture strings which are copied in substitution string with $1, $2, $3.

I hope this helps.