> I'm trying to compile some program with
> gcc 2.4.5 on Solaris and can't figure out
> in what library are the following subroutines are located:
> bcopy, bzero, bcmp, index, rindex?

If you cannot find the functions on your machine, the following defines
will do:

# include	<memory.h>
# define	bcopy(s,d,l)	memcpy((d),(s),(l))
# define	bzero(d,l)	memset((d),0,(l))
# define	bcmp(s1,s2,l)	memcmp((s2),(s1),(l))

# include	<string.h>
# define	index(s,c)	strchr((s),(c))
# define	rindex(s,c)	strrchr((s),(c))

Look into the manual for memory(3C) and string(3C).