Rev 4874 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4921 | Serge | 1 | /* |
| 2 | FUNCTION |
||
| 3 | < |
||
| 4 | |||
| 5 | INDEX |
||
| 6 | strncpy |
||
| 7 | |||
| 8 | ANSI_SYNOPSIS |
||
| 9 | #include |
||
| 10 | char *strncpy(char *restrict <[dst]>, const char *restrict <[src]>, |
||
| 11 | size_t <[length]>); |
||
| 12 | |||
| 13 | TRAD_SYNOPSIS |
||
| 14 | #include |
||
| 15 | char *strncpy(<[dst]>, <[src]>, <[length]>) |
||
| 16 | char *<[dst]>; |
||
| 17 | char *<[src]>; |
||
| 18 | size_t <[length]>; |
||
| 19 | |||
| 20 | DESCRIPTION |
||
| 21 | < |
||
| 22 | the string pointed to by <[src]> (including the terminating |
||
| 23 | null character) to the array pointed to by <[dst]>. If the |
||
| 24 | string pointed to by <[src]> is shorter than <[length]> |
||
| 25 | characters, null characters are appended to the destination |
||
| 26 | array until a total of <[length]> characters have been |
||
| 27 | written. |
||
| 28 | |||
| 29 | RETURNS |
||
| 30 | This function returns the initial value of <[dst]>. |
||
| 31 | |||
| 32 | PORTABILITY |
||
| 33 | < |
||
| 34 | |||
| 35 | < |
||
| 36 | |||
| 37 | QUICKREF |
||
| 38 | strncpy ansi pure |
||
| 39 | */ |
||
| 40 | |||
| 41 | #include |
||
| 42 | #include |
||
| 43 | |||
| 44 | /*SUPPRESS 560*/ |
||
| 45 | /*SUPPRESS 530*/ |
||
| 46 | |||
| 47 | /* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
||
| 48 | #define UNALIGNED(X, Y) \ |
||
| 49 | (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
||
| 50 | |||
| 51 | #if LONG_MAX == 2147483647L |
||
| 52 | #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) |
||
| 53 | #else |
||
| 54 | #if LONG_MAX == 9223372036854775807L |
||
| 55 | /* Nonzero if X (a long int) contains a NULL byte. */ |
||
| 56 | #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) |
||
| 57 | #else |
||
| 58 | #error long int is not a 32bit or 64bit type. |
||
| 59 | #endif |
||
| 60 | #endif |
||
| 61 | |||
| 62 | #ifndef DETECTNULL |
||
| 63 | #error long int is not a 32bit or 64bit byte |
||
| 64 | #endif |
||
| 65 | |||
| 66 | #define TOO_SMALL(LEN) ((LEN) < sizeof (long)) |
||
| 67 | |||
| 68 | char * |
||
| 69 | _DEFUN (strncpy, (dst0, src0), |
||
| 70 | char *__restrict dst0 _AND |
||
| 71 | _CONST char *__restrict src0 _AND |
||
| 72 | size_t count) |
||
| 73 | { |
||
| 74 | #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
||
| 75 | char *dscan; |
||
| 76 | _CONST char *sscan; |
||
| 77 | |||
| 78 | dscan = dst0; |
||
| 79 | sscan = src0; |
||
| 80 | while (count > 0) |
||
| 81 | { |
||
| 82 | --count; |
||
| 83 | if ((*dscan++ = *sscan++) == '\0') |
||
| 84 | break; |
||
| 85 | } |
||
| 86 | while (count-- > 0) |
||
| 87 | *dscan++ = '\0'; |
||
| 88 | |||
| 89 | return dst0; |
||
| 90 | #else |
||
| 91 | char *dst = dst0; |
||
| 92 | _CONST char *src = src0; |
||
| 93 | long *aligned_dst; |
||
| 94 | _CONST long *aligned_src; |
||
| 95 | |||
| 96 | /* If SRC and DEST is aligned and count large enough, then copy words. */ |
||
| 97 | if (!UNALIGNED (src, dst) && !TOO_SMALL (count)) |
||
| 98 | { |
||
| 99 | aligned_dst = (long*)dst; |
||
| 100 | aligned_src = (long*)src; |
||
| 101 | |||
| 102 | /* SRC and DEST are both "long int" aligned, try to do "long int" |
||
| 103 | sized copies. */ |
||
| 104 | while (count >= sizeof (long int) && !DETECTNULL(*aligned_src)) |
||
| 105 | { |
||
| 106 | count -= sizeof (long int); |
||
| 107 | *aligned_dst++ = *aligned_src++; |
||
| 108 | } |
||
| 109 | |||
| 110 | dst = (char*)aligned_dst; |
||
| 111 | src = (char*)aligned_src; |
||
| 112 | } |
||
| 113 | |||
| 114 | while (count > 0) |
||
| 115 | { |
||
| 116 | --count; |
||
| 117 | if ((*dst++ = *src++) == '\0') |
||
| 118 | break; |
||
| 119 | } |
||
| 120 | |||
| 121 | while (count-- > 0) |
||
| 122 | *dst++ = '\0'; |
||
| 123 | |||
| 124 | return dst0; |
||
| 125 | #endif /* not PREFER_SIZE_OVER_SPEED */ |
||
| 126 | } |