re_comp man page

re_comp, re_exec — BSD regex functions


#define _REGEX_RE_COMP
#include <sys/types.h>
#include <regex.h>

char *re_comp(const char *regex);

int re_exec(const char *string);


re_comp() is used to compile the null-terminated regular expression pointed to by regex. The compiled pattern occupies a static area, the pattern buffer, which is overwritten by subsequent use of re_comp(). If regex is NULL, no operation is performed and the pattern buffer's contents are not altered.

re_exec() is used to assess whether the null-terminated string pointed to by string matches the previously compiled regex.

Return Value

re_comp() returns NULL on successful compilation of regex otherwise it returns a pointer to an appropriate error message.

re_exec() returns 1 for a successful match, zero for failure.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
re_comp(), re_exec() Thread safety MT-Unsafe

Conforming to



These functions are obsolete; the functions documented in regcomp(3) should be used instead.

See Also

regcomp(3), regex(7), GNU regex manual


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Referenced By


re_exec(3) is an alias of re_comp(3).

2015-03-02 GNU Linux Programmer's Manual