SmallBASIC Guide

The operator LIKE

LIKE is a regular-expression operator. It is compares the left part of the expression with the pattern (right part). Since the original regular expression code is too big (for handhelds), I use only a subset of it, based on an excellent old stuff by J. Kercheval (match.c, public-domain, 1991). But there is an option to use PCRE (Perl-Compatible Regular Expression library) on systems that is supported (Linux); (see OPTION). The same code is used for filenames (FILES(), DIRWALK) too. In the pattern string:

*	matches any sequence of characters (zero or more)
?	matches any character
[SET]	matches any character in the specified set,
[!SET] or [^SET]	matches any character not in the specified set.

A set is composed of characters or ranges; a range looks like character hyphen character (as in 0-9 or A-Z). [0-9a-zA-Z_] is the minimal set of characters allowed in the [..] pattern construct. To suppress the special syntactic significance of any of `[]*?!^-\', and match the character exactly, precede it with a `\'.

? "Hello" LIKE "*[oO]" : REM TRUE
? "Hello" LIKE "He??o" : REM TRUE
? "Hello" LIKE "hello" : REM FALSE
? "Hello" LIKE "[Hh]*" : REM TRUE

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