Version 5 of string match

string match ?-nocase? pattern string

See if pattern matches string; return 1 if it does, 0 if it doesn't. If -nocase is specified, then the pattern attempts to match against the string in a case insensitive manner. For the two strings to match, their contents must be identical except that the following special sequences may appear in pattern:

* Matches any sequence of characters in string, including a null string.
? Matches any single character in string.
[chars] Matches any character in the set given by chars. If a sequence of the form x-y appears in chars, then any character between x and y, inclusive, will match. When used with -nocase, the end points of the range are converted to lower case first. Whereas {[A-z]} matches '_' when matching case-sensitively ('_' falls between the 'Z' and 'a'), with -nocase this is considered like {[A-Za-z]} (and probably what was meant in the first place).
\x Matches the single character x. This provides a way of avoiding the special interpretation of the characters *?[]\ in pattern.