projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 586c39b1 DF |
1 | /* |
| 2 | * Copyright (c) 1983 Regents of the University of California. | |
| 493b70ca KB |
3 | * All rights reserved. |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms are permitted | |
| f4f66d2c KB |
6 | * provided that the above copyright notice and this paragraph are |
| 7 | * duplicated in all such forms and that any documentation, | |
| 8 | * advertising materials, and other materials related to such | |
| 9 | * distribution and use acknowledge that the software was developed | |
| 10 | * by the University of California, Berkeley. The name of the | |
| 11 | * University may not be used to endorse or promote products derived | |
| 12 | * from this software without specific prior written permission. | |
| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
| 15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
| 586c39b1 DF |
16 | */ |
| 17 | ||
| f4f66d2c KB |
18 | #if defined(LIBC_SCCS) && !defined(lint) |
| 19 | .asciz "@(#)strncat.s 5.5 (Berkeley) %G%" | |
| 20 | #endif /* LIBC_SCCS and not lint */ | |
| 4bd005a5 SL |
21 | |
| 22 | /* | |
| 23 | * Concatenate string s2 on the end of s1 | |
| 24 | * and return the base of s1. The parameter | |
| 25 | * n is the maximum length of string s2 to | |
| 26 | * concatenate. | |
| 27 | * | |
| 28 | * char * | |
| 29 | * strncat(s1, s2, n) | |
| 30 | * char *s1, *s2; | |
| 31 | * int n; | |
| 32 | */ | |
| dadab5a2 | 33 | #include "DEFS.h" |
| 4bd005a5 | 34 | |
| dadab5a2 | 35 | ENTRY(strncat, R6) |
| 4bd005a5 SL |
36 | movl 12(ap),r6 # r6 = n |
| 37 | bleq done # n <= 0 | |
| 38 | movl 4(ap),r3 # r3 = s1 | |
| 39 | movl r3,r1 | |
| 40 | 0: | |
| 41 | locc $0,$65535,(r1) | |
| 42 | beql 0b | |
| 43 | movl r1,r3 # r3 = index(s1, '\0'); | |
| 44 | movl 8(ap),r1 # r1 = s2 | |
| 45 | 1: | |
| 46 | movzwl $65535,r2 # r2 = bytes in first chunk | |
| 47 | cmpl r6,r2 # r2 = min(bytes in chunk, n); | |
| 48 | jgeq 2f | |
| 49 | movl r6,r2 | |
| 50 | 2: | |
| 51 | subl2 r2,r6 # update n | |
| 52 | locc $0,r2,(r1) # '\0' found? | |
| 53 | jneq 3f | |
| 54 | subl2 r2,r1 # back up pointer updated by locc | |
| 55 | movc3 r2,(r1),(r3) # copy in next piece | |
| 56 | tstl r6 # run out of space? | |
| 57 | jneq 1b | |
| 58 | clrb (r3) # force '\0' termination | |
| 59 | jbr done | |
| 60 | 3: | |
| 61 | subl2 r0,r2 # r2 = number of bytes to move | |
| 62 | subl2 r2,r1 # back up pointer updated by locc | |
| 63 | incl r2 # copy '\0' as well | |
| 64 | movc3 r2,(r1),(r3) # copy in last piece | |
| 65 | done: | |
| 66 | movl 4(ap),r0 # return s1 | |
| 67 | ret |