Regex split string preserving quotes

Question

I need to split a string like the one below, based on space as the delimiter. But any space within a quote should be preserved.

research library \"not availa         


        

Answer 1

Here you go:

C#:

Regex.Matches(subject, @"([^\s]*""[^""]+""[^\s]*)|\w+")

Regular expression:

([^\s]*\"[^\"]+\"[^\s]*)|\w+

Answer 2

As long as there can be no escaped quoted inside quoted strings, the following should work:

splitArray = Regex.Split(subjectString, "(?<=^[^\"]*(?:\"[^\"]*\"[^\"]*)*) (?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)");

This regex splits on space characters only if they are preceded and followed by an even number of quotes.

The regex without all those escaped quotes, explained:

(?<=      # Assert that it's possible to match this before the current position (positive lookbehind):
 ^        # The start of the string
 [^"]*    # Any number of non-quote characters
 (?:      # Match the following group...
  "[^"]*  # a quote, followed by any number of non-quote characters
  "[^"]*  # the same
 )*       # ...zero or more times (so 0, 2, 4, ... quotes will match)
)         # End of lookbehind assertion.
[ ]       # Match a space
(?=       # Assert that it's possible to match this after the current position (positive lookahead):
 (?:      # Match the following group...
  [^"]*"  # see above
  [^"]*"  # see above
 )*       # ...zero or more times.
 [^"]*    # Match any number of non-quote characters
 $        # Match the end of the string
)         # End of lookahead assertion