This is regexp.h in view mode; [Download] [Up]

 * Definitions etc. for regexp(3) routines.
 * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
 * not the System V one.
#define NSUBEXP  10
typedef struct regexp {
	char *startp[NSUBEXP];
	char *endp[NSUBEXP];
	char regstart;		/* Internal use only. */
	char reganch;		/* Internal use only. */
	char *regmust;		/* Internal use only. */
	int regmlen;		/* Internal use only. */
	char program[1];	/* Unwarranted chumminess with compiler. */
} regexp;

extern regexp *regcomp();
extern int regexec();
extern void regsub();
extern void regerror();

These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.