Question

Working on pure-ruby implementation of XCode project file parser, PBXProject, and need little help with regex.

So the PBXProject file has bunch of weird coed lines, which mixed contents. What I have now is regex, (.*?) = (.*?)( \/\* (.*) \*\/)?; ? which works on simpler cases (first line). But for second line, it cuts too early (to first ; -character).

isa = PBXBuildFile; fileRef = C0480C2015F4F91F00E0A2F4 /* zip.c */;

isa = PBXBuildFile; fileRef = C0480C2315F4F91F00E0A2F4 /* ZipArchive.mm */; settings = {COMPILER_FLAGS = "-fno-objc-arc"; };

So what I want out of those lines are simple name = value pairs, i.e.

isa = PBXBuildFile
settings = {COMPILER_FLAGS = "-fno-objc-arc"; }

Easy way to achieve this with one regex?

Answer 1

This regex will work just fine:

[a-zA-Z0-9]*\s*?=\s*?.*?(?:{[^}]*}|(?=;))

Note that only one level of brackets is allowed, the regex will not process nested brackets.

From your example, the following lines will be catched:

isa = PBXBuildFile
fileRef = C0480C2015F4F91F00E0A2F4 /* zip.c */
isa = PBXBuildFile
fileRef = C0480C2315F4F91F00E0A2F4 /* ZipArchive.mm */
settings = {COMPILER_FLAGS = "-fno-objc-arc"; }

Here’s the explanation of regex:

[a-zA-Z0-9]*\s*?=\s*?.*?(?:{[^}]*}|(?=;))

Options: ^ and $ match at line breaks

Match a single character present in the list below «[a-zA-Z0-9]*»
    Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
    A character in the range between “a” and “z” «a-z»
    A character in the range between “A” and “Z” «A-Z»
    A character in the range between “0” and “9” «0-9»
Match a single character that is a “whitespace character” (spaces, tabs, and line breaks) «\s*?»
    Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match the character “=” literally «=»
Match a single character that is a “whitespace character” (spaces, tabs, and line breaks) «\s*?»
    Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match any single character that is not a line break character «.*?»
    Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match the regular expression below «(?:(?={){[^}]*}|(?=;))»
    Match either the regular expression below (attempting the next alternative only if this one fails) «(?={){[^}]*}»
        Match the character “{” literally «{»
        Match any character that is NOT a “}” «[^}]*»
            Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
        Match the character “}” literally «}»
    Or match regular expression number 2 below (the entire group fails if this one fails to match) «(?=;)»
        Assert that the regex below can be matched, starting at this position (positive lookahead) «(?=;)»
            Match the character “;” literally «;»