1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8#if defined(LIBC_SCCS) && !defined(lint) 9 .asciz "@(#)strncat.s 8.1 (Berkeley) 06/04/93" 10#endif /* LIBC_SCCS and not lint */ 11 12/* 13 * Concatenate string s2 on the end of s1 14 * and return the base of s1. The parameter 15 * n is the maximum length of string s2 to 16 * concatenate. 17 * 18 * char * 19 * strncat(s1, s2, n) 20 * char *s1, *s2; 21 * int n; 22 */ 23#include "DEFS.h" 24 25ENTRY(strncat, R6) 26 movl 12(ap),r6 # r6 = n 27 bleq done # n <= 0 28 movl 4(ap),r3 # r3 = s1 29 movl r3,r1 300: 31 locc $0,$65535,(r1) 32 beql 0b 33 movl r1,r3 # r3 = index(s1, '\0'); 34 movl 8(ap),r1 # r1 = s2 351: 36 movzwl $65535,r2 # r2 = bytes in first chunk 37 cmpl r6,r2 # r2 = min(bytes in chunk, n); 38 jgeq 2f 39 movl r6,r2 402: 41 subl2 r2,r6 # update n 42 locc $0,r2,(r1) # '\0' found? 43 jneq 3f 44 subl2 r2,r1 # back up pointer updated by locc 45 movc3 r2,(r1),(r3) # copy in next piece 46 tstl r6 # run out of space? 47 jneq 1b 48 clrb (r3) # force '\0' termination 49 jbr done 503: 51 subl2 r0,r2 # r2 = number of bytes to move 52 subl2 r2,r1 # back up pointer updated by locc 53 incl r2 # copy '\0' as well 54 movc3 r2,(r1),(r3) # copy in last piece 55done: 56 movl 4(ap),r0 # return s1 57 ret 58