source: trunk/minix/lib/i86/string/_strncpy.s@ 9

!       _strncpy()                                      Author: Kees J. Bot
!                                                               27 Jan 1994
.sect .text; .sect .rom; .sect .data; .sect .bss

! char *_strncpy(char *s1, const char *s2, size_t cx)
!       Copy string s2 to s1.
!
.sect .text
.define __strncpy
__strncpy:
        mov     di, 6(bp)       ! di = string s2
        xorb    al, al          ! Look for a zero byte
        mov     dx, cx          ! Save maximum count
        cld
  repne scasb                   ! Look for end of s2
        sub     dx, cx          ! Number of bytes in s2 including null
        xchg    cx, dx
        mov     si, 6(bp)       ! si = string s2
        mov     di, 4(bp)       ! di = string s1
    rep movsb                   ! Copy bytes
        ret