NAME

regex, re_comp, re_exec − regular expression handler

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

ed(1), ex(1), grep(1V)

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 \)

Sun Release 4.1  —  Last change: 6 October 1987