! strncmp() Author: Kees J. Bot ! 27 Jan 1994 .sect .text; .sect .rom; .sect .data; .sect .bss ! int strncmp(const char *s1, const char *s2, size_t cx) ! Compare two strings. ! .sect .text .define __strncmp __strncmp: push bp mov bp, sp push si push di xor ax, ax ! Prepare return value test cx, cx ! Max length is zero? je equal mov si, 4(bp) ! si = string s1 mov di, 6(bp) ! di = string s2 cld compare: cmpsb ! Compare two bytes jne unequal cmpb -1(si), #0 ! End of string? je equal dec cx ! Length limit reached? jne compare jmp equal unequal: ja after sub ax, #2 ! if (s1 < s2) ax -= 2; after: inc ax ! ax++, now it's -1 or 1 equal: pop di pop si pop bp ret