I'm trying to match a pair of special characters, while excluding the enclosed content from the match. For example, ~some enclosed content~ should match only the pair of ~ and leave out some enclosed content entirely. I can only use vanilla PCRE, and capture groups aren't an option.
My match criteria for the entire string is ~([^\s].*?(?<!\s))~. Matching the first and second ~ separately would also be acceptable.
CodePudding user response：
Looking at your pattern, you want a non whitespace char right after the opening ~ and a non whitespace char right before the closing ~
As those are the delimiters, and the non whitespace char should also not be ~ itself, you might use:
~(?=[^~\s](?:[^~\r\n]*[^\s~])?~)|(?<=~)[^\s~](?:[^~\r\n]*[^\s~])?\K~
Explanation
~Match literally(?=Positive lookahead, assert that to the right is[^~\s]Match a non whitespace char except for~(?:Non capture group[^~\r\n]*[^\s~]Match repeating any char other than a newline or~followed by a non whitespace char except for~
)?Close non capture group and make it optional (to also match a single char~a~)~Match literally
)Close the lookahead|Or(?<=~)Positive lookbehind, assert~to the left[^\s~]Match a non whitespace char except for~(?:[^~\r\n]*[^\s~])?Same optional pattern as in the lookahead\KForget what is matched so far~Match literally