strntran.c

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

/*  File   : strntrans.c
    Author : Richard A. O'Keefe.
    Updated: 2 June 1984
    Defines: strntrans()

    strntrans(dst, src, len, from, to)
    Moves characters from src to dst, translating characters in from[]
    to the corresponding characters in to[], until either len characters
    have been moved or a NUL has been moved.  If fewer than len characters
    are moved, the remainder of dst will be filled with NULs, much like
    strncpy and family.  No value is returned.

    Apology: in the previous distribution of this package, strntrans was
    defined the way memtrans is now defined.  This is more consistent with
    the general naming conventions.
*/

#include "strings.h"
#include "_str2map.h"

#if	VaxAsm

void strntrans(dst, src, len, from, to)
    _char_ *dst, *src, *from, *to;
    int len;
    {
	_str2map(0, from, to);
	asm("movtuc 20(ap),*8(ap),$0,__map_vec,20(ap),*4(ap)");
	/* now pad the destination out with NUL characters */
	asm("movc5 $0,*8(ap),$0,r4,(r5)");
    }

#else  ~VaxAsm

void strntrans(dst, src, len, from, to)
    register _char_ *dst, *src;
    register int len;
    _char_ *from, *to;
    {
	_str2map(0, from, to);
	while (--len >= 0 && (*dst++ = _map_vec[*src++])) ;
	while (--len >= 0) *dst++ = NUL;
    }

#endif	VaxAsm