strings.h

Many C samples. It is a good sample for students to learn C language.

/*  File   : strings.h
    Author : Richard A. O'Keefe.
    Updated: 1 June 1984
    Purpose: Header file for the "string(3C)" package.

    All  the  routines  in  this  package  are  the  original  work   of
    R.A.O'Keefe.   Any  resemblance  between  them  and  any routines in
    licensed software is due entirely  to  these  routines  having  been
    written  using the "man 3 string" UNIX manual page, or in some cases
    the "man 1 sort" manual page as a specification.  See the READ-ME to
    find the conditions under which these routines may be used & copied.
*/

#ifndef	NullS
#define	NullS	(char*)0
#define NUL	'\0'

/*  MAKE SURE THE RIGHT VERSION OF THE FOLLOWING MACRO IS INSTALLED!  */

#if	vax | pdp11 | m68000 | perq
#define CharsAreSigned 1			/* default is unsigned */
#endif	vax | pdp11 | m68000 | perq

#if	CharsAreSigned
#define	int2char(i)	(((i)<<((sizeof (int) -1)*8))>>((sizeof (int) -1)*8))
#else  !CharsAreSigned
#define	int2char(i)	((i)&255)
#endif	CharsAreSigned
/*  If characters are signed, but the above doesn't work,
    try	((127-(255&~(i)))^(-128))
*/

#ifndef	_AlphabetSize
#define	_AlphabetSize	128
#endif

#if	_AlphabetSize == 128
typedef	char _char_;
#endif
#if	_AlphabetSize == 256
typedef	unsigned char _char_;
#endif

/*  NullS is the "nil" character  pointer.   NULL  would  work  in  most
    cases,  but  in  some  C  compilers  pointers and integers may be of
    different sizes, so it is handy to have a nil pointer that  one  can
    pass to a function as well as compare pointers against.

    NUL is the ASCII name for the character with code 0.  Its use to end
    strings is a convention of the C programming language.  There are in
    fact three different end of string conventions supported by routines
    in this package:
	str<opn>	: end at the first NUL character
	strn<opn>	: end at the first NUL character, or when the
			  extra "len" parameter runs out.
	mem<opn>,b<opn>	: length determined solely by "len" parameter.
    Unfortunately, the VAX hardware only supports the last convention, a
    pity really.  Fortran 77 users BEWARE: Fortran 77's convention is an
    entirely different one, and there are NO routines in this package as
    yet which support it.  (But see section 3F of the 4.2 BSD manual.)

    The routines which move characters around don't  care  whether  they
    are  signed or unsigned.  But the routines which compare a character
    in a string with an argument, or use a character from a string as an
    index into an array, do care.  I have assumed that
	_AlphabetSize = 128 => only 0..127 appear in strings
	_AlphabetSize = 256 => only 0..255 appear in strings
    The files _str2set.c and _str2map.c declare character vectors  using
    this  size.  If you don't have unsigned char, your machine may treat
    char as unsigned anyway.

    Some string operations (*cmp, *chr) are explicitly defined in various
    UNIX manuals to use "native" comparison, so I have not used _char_ in
    them.  This package is meant to be compatible, not rational!
*/

extern	char	*strcat(/*char^,char^*/);
extern	char	*strncat(/*char^,char^,int*/);

extern	int	strcmp(/*char^,char^*/);
extern	int	strncmp(/*char^,char^,int*/);

#define streql	!strcmp
#define strneql	!strncmp	/* (str-N)-eql not str-(neq-l)! */

extern	char	*strcpy(/*char^,char^*/);
extern	char	*strncpy(/*char^,char^,int*/);

extern	int	strlen(/*char^*/);
extern	int	strnlen(/*char^,int*/);

extern	char	*strchr(/*char^,_char_*/);
extern	char	*strrchr(/*char^,_char_*/);
#define	index	strchr
#define	rindex	strrchr

extern	char	*strmov(/*char^,char^*/);
extern	char	*strnmov(/*char^,char^,int*/);

extern	void	strrev(/*char^,char^*/);
extern	void	strnrev(/*char^,char^,int*/);

extern	char	*strend(/*char^*/);
extern	char	*strnend(/*char^*/);

extern	char	*strpbrk(/*char^,char^*/);
extern	char	*strcpbrk(/*char^,char^*/);

extern	int	strspn(/*char^,char^*/);
extern	int	strcspn(/*char^,char^*/);

extern	char	*strtok(/*char^,char^*/);
extern	void	istrtok(/*char^,char^*/);

extern	char	*strpack(/*_char_^,_char_^,char^,int*/);
extern	char	*strcpack(/*_char_^,_char_^,char^,int*/);

extern	int	strrpt(/*char^,char^,int*/);
extern	int	strnrpt(/*char^,int,char^,int*/);

extern	void	strtrans(/*_char_^,_char_^,_char_^,_char_^*/);
extern	void	strntrans(/*_char_^,_char_^,int,_char_^,_char_^*/);

extern	char	*strtrim(/*char^,char^,char^,int*/);
extern	char	*strctrim(/*char^,char^,char^,int*/);

extern	char	*strfield(/*char^,int,int,int,int*/);
extern	char	*strkey(/*char^,char^,char^,char^*/);

extern	char	*strfind(/*char^,char^*/);
extern	char	*strrepl(/*char^,char^,char^,char^*/);

extern	void	bcopy(/*char^,char^,int*/);
extern	void	bmove(/*char^,char^,int*/);

extern	void	bfill(/*char^,int,char*/);
extern	void	bzero(/*char^,int*/);

extern	int	bcmp(/*char^,char^,int*/);
#define	beql	!bcmp

extern	int	ffs(/*int*/);
extern	int	ffc(/*int*/);

extern	char	*substr(/*char^,char^,int,int*/);

extern	char	*strxcat(/*VARARGS*/);
extern	char	*strxcpy(/*VARARGS*/);
extern	char	*strxmov(/*VARARGS*/);

extern	char	*strxncat(/*VARARGS*/);
extern	char	*strxncpy(/*VARARGS*/);
extern	char	*strxnmov(/*VARARGS*/);

#endif	NullS

#ifndef	memeql
#include "memory.h"
#endif	memeql