0,0 → 1,104 |
/* |
FUNCTION |
<<strcat>>---concatenate strings |
|
INDEX |
strcat |
|
ANSI_SYNOPSIS |
#include <string.h> |
char *strcat(char *<[dst]>, const char *<[src]>); |
|
TRAD_SYNOPSIS |
#include <string.h> |
char *strcat(<[dst]>, <[src]>) |
char *<[dst]>; |
char *<[src]>; |
|
DESCRIPTION |
<<strcat>> appends a copy of the string pointed to by <[src]> |
(including the terminating null character) to the end of the |
string pointed to by <[dst]>. The initial character of |
<[src]> overwrites the null character at the end of <[dst]>. |
|
RETURNS |
This function returns the initial value of <[dst]> |
|
PORTABILITY |
<<strcat>> is ANSI C. |
|
<<strcat>> requires no supporting OS subroutines. |
|
QUICKREF |
strcat ansi pure |
*/ |
|
#include <string.h> |
#include <limits.h> |
|
/* Nonzero if X is aligned on a "long" boundary. */ |
#define ALIGNED(X) \ |
(((long)X & (sizeof (long) - 1)) == 0) |
|
#if LONG_MAX == 2147483647L |
#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) |
#else |
#if LONG_MAX == 9223372036854775807L |
/* Nonzero if X (a long int) contains a NULL byte. */ |
#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) |
#else |
#error long int is not a 32bit or 64bit type. |
#endif |
#endif |
|
#ifndef DETECTNULL |
#error long int is not a 32bit or 64bit byte |
#endif |
|
|
/*SUPPRESS 560*/ |
/*SUPPRESS 530*/ |
|
char * |
_DEFUN (strcat, (s1, s2), |
char *s1 _AND |
_CONST char *s2) |
{ |
#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
char *s = s1; |
|
while (*s1) |
s1++; |
|
while (*s1++ = *s2++) |
; |
return s; |
#else |
char *s = s1; |
|
|
/* Skip over the data in s1 as quickly as possible. */ |
if (ALIGNED (s1)) |
{ |
unsigned long *aligned_s1 = (unsigned long *)s1; |
while (!DETECTNULL (*aligned_s1)) |
aligned_s1++; |
|
s1 = (char *)aligned_s1; |
} |
|
while (*s1) |
s1++; |
|
/* s1 now points to the its trailing null character, we can |
just use strcpy to do the work for us now. |
|
?!? We might want to just include strcpy here. |
Also, this will cause many more unaligned string copies because |
s1 is much less likely to be aligned. I don't know if its worth |
tweaking strcpy to handle this better. */ |
strcpy (s1, s2); |
|
return s; |
#endif /* not PREFER_SIZE_OVER_SPEED */ |
} |