Why do matches aginst (.*) and (.*?) result in exactly the same result?

Because there's only one ghi. 

...
/c/ matches "c" (at position 3)
   /d/ matches "d"
      /.*/ matches " cd EF ghi jkl"
         /g/ fails -> backtrack
      /.*/ matches " cd EF ghi jk"
         /g/ fails -> backtrack
      /.*/ matches " cd EF ghi j"
         /g/ fails -> backtrack
      ...
      /.*/ matches " cd EF "
         /g/ matches "g"
            /h/ matches "h"
               /i/ matches "i" -> success

[download]
...
/c/ matches "c" (at position 3)
   /d/ matches "d"
      /.*?/ matches ""
         /g/ fails -> backtrack
      /.*?/ matches " "
         /g/ fails -> backtrack
      /.*?/ matches " c"
         /g/ fails -> backtrack
      ...
      /.*?/ matches " cd EF "
         /g/ matches "g"
            /h/ matches "h"
               /i/ matches "i" -> success

[download]

What needs to be done to get only the "EF" as a result?

(?s:(?!STRING).)* is to STRING as [^CHAR]* is to CHAR. 

/cd(?:(?!cd|ghi).)ghi/s

[download]

Note: Unlike the trick of adding ^.* to the start of the pattern, this pattern can be used in other patterns.

Note: I think want "EF" instead of " EF ", but it's easier just to trim the whitespaces afterwards.

In reply to Re: Regex problem - (non)greedy? by ikegami
in thread Regex problem - (non)greedy? by Anonymous Monk

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