| 0,0 → 1,114 |
|---|
| /* |
| FUNCTION |
| <<stpncpy>>---counted copy string returning a pointer to its end |
| |
| INDEX |
| stpncpy |
| |
| ANSI_SYNOPSIS |
| #include <string.h> |
| char *stpncpy(char *<[dst]>, const char *<[src]>, size_t <[length]>); |
| |
| TRAD_SYNOPSIS |
| #include <string.h> |
| char *stpncpy(<[dst]>, <[src]>, <[length]>) |
| char *<[dst]>; |
| char *<[src]>; |
| size_t <[length]>; |
| |
| DESCRIPTION |
| <<stpncpy>> copies not more than <[length]> characters from the |
| the string pointed to by <[src]> (including the terminating |
| null character) to the array pointed to by <[dst]>. If the |
| string pointed to by <[src]> is shorter than <[length]> |
| characters, null characters are appended to the destination |
| array until a total of <[length]> characters have been |
| written. |
| |
| RETURNS |
| This function returns a pointer to the end of the destination string, |
| thus pointing to the trailing '\0', or, if the destination string is |
| not null-terminated, pointing to dst + n. |
| |
| PORTABILITY |
| <<stpncpy>> is a GNU extension, candidate for inclusion into POSIX/SUSv4. |
| |
| <<stpncpy>> requires no supporting OS subroutines. |
| |
| QUICKREF |
| stpncpy gnu |
| */ |
| |
| #include <string.h> |
| #include <limits.h> |
| |
| /*SUPPRESS 560*/ |
| /*SUPPRESS 530*/ |
| |
| /* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
| #define UNALIGNED(X, Y) \ |
| (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
| |
| #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 |
| |
| #define TOO_SMALL(LEN) ((LEN) < sizeof (long)) |
| |
| char * |
| _DEFUN (stpncpy, (dst, src), |
| char *dst _AND |
| _CONST char *src _AND |
| size_t count) |
| { |
| char *ret = NULL; |
| |
| #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
| long *aligned_dst; |
| _CONST long *aligned_src; |
| |
| /* If SRC and DEST is aligned and count large enough, then copy words. */ |
| if (!UNALIGNED (src, dst) && !TOO_SMALL (count)) |
| { |
| aligned_dst = (long*)dst; |
| aligned_src = (long*)src; |
| |
| /* SRC and DEST are both "long int" aligned, try to do "long int" |
| sized copies. */ |
| while (count >= sizeof (long int) && !DETECTNULL(*aligned_src)) |
| { |
| count -= sizeof (long int); |
| *aligned_dst++ = *aligned_src++; |
| } |
| |
| dst = (char*)aligned_dst; |
| src = (char*)aligned_src; |
| } |
| #endif /* not PREFER_SIZE_OVER_SPEED */ |
| |
| while (count > 0) |
| { |
| --count; |
| if ((*dst++ = *src++) == '\0') |
| { |
| ret = dst - 1; |
| break; |
| } |
| } |
| |
| while (count-- > 0) |
| *dst++ = '\0'; |
| |
| return ret ? ret : dst; |
| } |