regex, re_comp, re_exec - regular expression handler

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SYNOPSIS

char *re_comp(s)
char *s;

re_exec(s) char *s;

DESCRIPTION

re_comp() compiles a string into an internal form suitable for pattern matching. re_exec() checks the argument string against the last string passed to re_comp().

re_comp() returns a NULL pointer if the string s was compiled successfully; otherwise a string containing an error message is returned. If re_comp() is passed 0 or a null string, it returns without changing the currently compiled regular expression.

re_exec() returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last compiled regular expression, and -1 if the compiled regular expression was invalid (indicating an internal error).

The strings passed to both re_comp() and re_exec() may have trailing or embedded NEWLINE characters; they are terminated by null characters. The regular expressions recognized are described in the manual entry for ed.1 given the above difference.

SEE ALSO

DIAGNOSTICS

re_exec() returns -1 for an internal error.

re_comp() returns one of the following strings if an error occurs:

No previous regular expression

Regular expression too long

unmatched \(

missing ]

too many \(\) pairs

unmatched \)

Created by unroff & hp-tools. © somebody (See intro for details). All Rights Reserved. Last modified 11/5/97