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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 3900 | Serge | 1 | /* |
| 2 | FUNCTION |
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| 3 | < |
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| 4 | |||
| 5 | INDEX |
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| 6 | stpncpy |
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| 7 | |||
| 8 | ANSI_SYNOPSIS |
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| 9 | #include |
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| 10 | char *stpncpy(char *<[dst]>, const char *<[src]>, size_t <[length]>); |
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| 11 | |||
| 12 | TRAD_SYNOPSIS |
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| 13 | #include |
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| 14 | char *stpncpy(<[dst]>, <[src]>, <[length]>) |
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| 15 | char *<[dst]>; |
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| 16 | char *<[src]>; |
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| 17 | size_t <[length]>; |
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| 18 | |||
| 19 | DESCRIPTION |
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| 20 | < |
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| 21 | the string pointed to by <[src]> (including the terminating |
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| 22 | null character) to the array pointed to by <[dst]>. If the |
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| 23 | string pointed to by <[src]> is shorter than <[length]> |
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| 24 | characters, null characters are appended to the destination |
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| 25 | array until a total of <[length]> characters have been |
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| 26 | written. |
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| 27 | |||
| 28 | RETURNS |
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| 29 | This function returns a pointer to the end of the destination string, |
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| 30 | thus pointing to the trailing '\0', or, if the destination string is |
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| 31 | not null-terminated, pointing to dst + n. |
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| 32 | |||
| 33 | PORTABILITY |
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| 34 | < |
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| 35 | |||
| 36 | < |
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| 37 | |||
| 38 | QUICKREF |
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| 39 | stpncpy gnu |
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| 40 | */ |
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| 41 | |||
| 42 | #include |
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| 43 | #include |
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| 44 | |||
| 45 | /*SUPPRESS 560*/ |
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| 46 | /*SUPPRESS 530*/ |
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| 47 | |||
| 48 | /* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
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| 49 | #define UNALIGNED(X, Y) \ |
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| 50 | (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
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| 51 | |||
| 52 | #if LONG_MAX == 2147483647L |
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| 53 | #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) |
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| 54 | #else |
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| 55 | #if LONG_MAX == 9223372036854775807L |
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| 56 | /* Nonzero if X (a long int) contains a NULL byte. */ |
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| 57 | #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) |
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| 58 | #else |
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| 59 | #error long int is not a 32bit or 64bit type. |
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| 60 | #endif |
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| 61 | #endif |
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| 62 | |||
| 63 | #ifndef DETECTNULL |
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| 64 | #error long int is not a 32bit or 64bit byte |
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| 65 | #endif |
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| 66 | |||
| 67 | #define TOO_SMALL(LEN) ((LEN) < sizeof (long)) |
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| 68 | |||
| 69 | char * |
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| 70 | _DEFUN (stpncpy, (dst, src), |
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| 71 | char *dst _AND |
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| 72 | _CONST char *src _AND |
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| 73 | size_t count) |
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| 74 | { |
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| 75 | char *ret = NULL; |
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| 76 | |||
| 77 | #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
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| 78 | long *aligned_dst; |
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| 79 | _CONST long *aligned_src; |
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| 80 | |||
| 81 | /* If SRC and DEST is aligned and count large enough, then copy words. */ |
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| 82 | if (!UNALIGNED (src, dst) && !TOO_SMALL (count)) |
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| 83 | { |
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| 84 | aligned_dst = (long*)dst; |
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| 85 | aligned_src = (long*)src; |
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| 86 | |||
| 87 | /* SRC and DEST are both "long int" aligned, try to do "long int" |
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| 88 | sized copies. */ |
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| 89 | while (count >= sizeof (long int) && !DETECTNULL(*aligned_src)) |
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| 90 | { |
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| 91 | count -= sizeof (long int); |
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| 92 | *aligned_dst++ = *aligned_src++; |
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| 93 | } |
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| 94 | |||
| 95 | dst = (char*)aligned_dst; |
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| 96 | src = (char*)aligned_src; |
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| 97 | } |
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| 98 | #endif /* not PREFER_SIZE_OVER_SPEED */ |
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| 99 | |||
| 100 | while (count > 0) |
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| 101 | { |
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| 102 | --count; |
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| 103 | if ((*dst++ = *src++) == '\0') |
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| 104 | { |
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| 105 | ret = dst - 1; |
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| 106 | break; |
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| 107 | } |
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| 108 | } |
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| 109 | |||
| 110 | while (count-- > 0) |
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| 111 | *dst++ = '\0'; |
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| 112 | |||
| 113 | return ret ? ret : dst; |
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| 114 | } |