ompile the regular expression PATTERN, with length LENGTH
   and syntax given by the global 're_syntax_options', into the buffer
   BUFFER.  Return NULL if successful, and an error string if not.

   To free the allocated storage, you must call 'regfree' on BUFFER.
   Note that the translate table must either have been initialized by
   'regcomp', with a malloc'ed value, or set to NULL before calling
   'regfree'.  */
extern const char *re_compile_pattern (const char *__pattern, size_t __length,
				       struct re_pattern_buffer *__buffer)
    _Attr_access_ ((__read_only__, 1, 2));


/* Compile a fastmap for the compiled pattern in BUFFER; used to
   accelerate searches.  Return 0 if successful and -2 if was an
   internal error.  */
extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);


/* Search in the string STRING (with length LENGTH) for the pattern
   compiled into BUFFER.  Start searching at position START, for RANGE
   characters.  Return the starting position of the match, -1 for no
   match, or -2 for an internal error.  Also return register
   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
extern regoff_t re_search (struct re_pattern_buffer *__buffer,
			   const char *__String, regoff_t __length,
			   regoff_t __start, regoff_t __range,
			   struct re_registers *__regs)
    _Attr_access_ ((__read_only__, 2, 3));


/* Like 're_search', but search in the concatenation of STRING1 and
   STRING2.  Also, stop searching at index START + STOP.  */
extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer,
			     const char *__string1, regoff_t __length1,
			     const char *__string2, regoff_t __length2,
			     regoff_t __start, regoff_t __range,
			     struct re_registers *__regs,
			     regoff_t __stop)
    _Attr_access_ ((__read_only__, 2, 3))
    _Attr_access_ ((__read_only__, 4, 5));


/* Like 're_search', but return how many characters in STRING the regexp
   in BUFFER matched, starting at position START.  */
extern regoff_t re_match (struct re_pattern_buffer *__buffer,
			  const char *__String, regoff_t __length,
			  regoff_t __start, struct re_registers *__regs)
    _Attr_access_ ((__read_only__, 2, 3));


/* Relates to 're_match' as 're_search_2' relates to 're_search'.  */
extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer,
			    const char *__string1, regoff_t __length1,
			    const char *__string2, regoff_t __length2,
			    regoff_t __start, struct re_registers *__regs,
			    regoff_t __stop)
    _Attr_access_ ((__read_only__, 2, 3))
    _Attr_access_ ((__read_only__, 4, 5));


/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
   for recording register information.  STARTS and ENDS must be
   allocated with malloc, and must each be at least 'NUM_REGS * sizeof
   (regoff_t)' bytes long.

   If NUM_REGS == 0, then subsequent matches should allocate their own
   register data.

   Unless this function is called, the first search or match using
   BUFFER will allocate its own register data, without
   freeing the old data.  */
extern void re_set_registers (struct re_pattern_buffer *__buffer,
			      struct re_registers *__regs,
			      __re_size_t __num_regs,
			      regoff_t *__starts, regoff_t *__ends);
#endif	/* Use GNU */

#if defined _REGEX_RE_COMP || (defined _LIBC && defined __USE_MISC)
/* 4.2 bsd compatibility.  */
extern char *re_comp (const char *);
extern int re_exec (const char *);
#endif

/* For plain 'restrict', use glibc's __restrict if defined.
   Otherwise, GCC 2.95 and later have "__restrict"; C99 compilers have
   "restrict", and "configure" may have defined "restrict".
   Other compilers use __restrict, __restrict__, and _Restrict, and
   'configure' might #define 'restrict' to those words, so pick a
   different name.  */
#ifndef _Restrict_
# if defined __restrict \
     || 2 < __GNUC__ + (95 <= __GNUC_MINOR__) \
     || __clang_major__ >= 3
#  define _Restrict_ __restrict
# elif 199901L <= __STDC_VERSION__ || defined restrict
#  define _Restrict_ restrict
# else
#  define _Restrict_
# endif
#endif
/* For the ISO C99 syntax
     array_name[restrict]
   use glibc's __restrict_arr if available.
   Otherwise, GCC 3.1 and clang support this syntax (but not in C++ mode).
   Other ISO C99 compilers support it as well.  */
#ifndef _Restrict_arr_
# ifdef __restrict_arr
#  define _Restrict_arr_ __restrict_arr
# elif ((199901L <= __STDC_VERSION__ \
         || 3 < __GNUC__ + (1 <= __GNUC_MINOR__) \
         || __clang_major__ >= 3) \
        && !defined __cplusplus)
#  define _Restrict_arr_ _Restrict_
# else
#  define _Restrict_arr_
# endif
#endif

/* POSIX compatibility.  */
extern int regcomp (regex_t *_Restrict_ __preg,
		    const char *_Restrict_ __pattern,
		    int __cflags);

extern int regexec (const regex_t *_Restrict_ __preg,
		    const char *_Restrict_ __String, size_t __nmatch,
		    regmatch_t __pmatch[_Restrict_arr_
					_REGEX_NELTS (__nmatch)],
		    int __eflags);

extern size_t regerror (int __errcode, const regex_t *_Restrict_ __preg,
			char *_Restrict_ __errbuf, size_t __errbuf_size)
    _Attr_access_ ((__write_only__, 3, 4));

extern void regfree (regex_t *__preg);

#if defined __GNUC__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
# pragma GCC diagnostic pop
#endif

#ifdef __cplusplus
}
#endif	/* C++ */

#endif /* regex.h */