Reputation: 1163
I'm constructing a regular expression that uses strings input by the user but the strings might contain special characters such as . \ or * and I want those to be treated as literals and not interpreted by their special meanings in the regex. I've tried this:
NSString *word = [input stringByReplacingOccurrencesOfRegex:@"(\\P{L})" withString:@"\\$1"];
but the non letter characters are converted to '$1' instead of being prefixed with a backslash. I've tried one and three backslashes in the second term but those give me an 'Unknown escape sequence' warning in XCode. How can I print a backslash without RegexKitLite thinking that I'm escaping the dollar sign?
Upvotes: 3
Views: 6112
Reputation: 22305
Write the expression as you normally would and then replace each single backslash with two. Thus
\.
becomes
\\.
and
\\
becomes
\\\\
Upvotes: 7