is used to compile the null-terminated regular expression pointed to by
The compiled pattern occupies a static area, the pattern buffer,
which is overwritten by subsequent use of
no operation is performed and the pattern buffer's contents are not
is used to assess whether the null-terminated string pointed to by
matches the previously compiled
returns NULL on successful compilation of
otherwise it returns a pointer to an appropriate error message.
returns 1 for a successful match, zero for failure.
These functions are obsolete; the functions documented in
should be used instead.