Re: Regexp Oddity

print "Matches: " . preg_match('/((?i)rah)\s+\1/', "RAH RAH") . "\n"; print "Matches: " . preg_match('/((?i)rah)\s+\1/', "rah rah") . is what you should use. trlists@clayst.com wrote:

I must be missing something obvious ... I am trying to use backreferences in a PCRE regexp to check for a repeated character, but they don't seem to work. I've used regexps often before, but never needed backreferences. For example this: print "Matches: " . preg_match("/(a)\1/", "aa"); prints: Matches: 0 It should be 1. In addition the basic examples in the manual fail. The manual says: For example, ((?i)rah)\s+\1 matches "rah rah" and "RAH RAH", but not "RAH rah", even though the original capturing subpattern is matched caselessly. I tested this with: print "Matches: " . preg_match("/((?i)rah)\s+\1/", "RAH RAH") . "\n"; print "Matches: " . preg_match("/((?i)rah)\s+\1/", "rah rah") . "\n"; Both show 0. For this test I'm running PHP 4.3.1 on Windows 2000. What am I missing? -- Tom

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