1 | /* |
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2 | FUNCTION |
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3 | <<mblen>>---minimal multibyte length function |
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4 | |
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5 | INDEX |
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6 | mblen |
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7 | |
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8 | SYNOPSIS |
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9 | #include <stdlib.h> |
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10 | int mblen(const char *<[s]>, size_t <[n]>); |
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11 | |
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12 | DESCRIPTION |
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13 | When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming |
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14 | implementation of <<mblen>>. In this case, the |
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15 | only ``multi-byte character sequences'' recognized are single bytes, |
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16 | and thus <<1>> is returned unless <[s]> is the null pointer or |
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17 | has a length of 0 or is the empty string. |
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18 | |
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19 | When _MB_CAPABLE is defined, this routine calls <<_mbtowc_r>> to perform |
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20 | the conversion, passing a state variable to allow state dependent |
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21 | decoding. The result is based on the locale setting which may |
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22 | be restricted to a defined set of locales. |
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23 | |
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24 | RETURNS |
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25 | This implementation of <<mblen>> returns <<0>> if |
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26 | <[s]> is <<NULL>> or the empty string; it returns <<1>> if not _MB_CAPABLE or |
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27 | the character is a single-byte character; it returns <<-1>> |
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28 | if the multi-byte character is invalid; otherwise it returns |
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29 | the number of bytes in the multibyte character. |
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30 | |
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31 | PORTABILITY |
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32 | <<mblen>> is required in the ANSI C standard. However, the precise |
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33 | effects vary with the locale. |
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34 | |
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35 | <<mblen>> requires no supporting OS subroutines. |
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36 | */ |
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37 | |
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38 | #ifndef _REENT_ONLY |
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39 | |
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40 | #include <newlib.h> |
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41 | #include <stdlib.h> |
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42 | #include <wchar.h> |
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43 | #include "local.h" |
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44 | |
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45 | int |
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46 | mblen (const char *s, |
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47 | size_t n) |
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48 | { |
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49 | #ifdef _MB_CAPABLE |
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50 | int retval = 0; |
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51 | struct _reent *reent = _REENT; |
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52 | mbstate_t *state; |
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53 | |
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54 | _REENT_CHECK_MISC(reent); |
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55 | state = &(_REENT_MBLEN_STATE(reent)); |
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56 | retval = __MBTOWC (reent, NULL, s, n, state); |
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57 | if (retval < 0) |
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58 | { |
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59 | state->__count = 0; |
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60 | return -1; |
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61 | } |
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62 | else |
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63 | return retval; |
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64 | |
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65 | #else /* not _MB_CAPABLE */ |
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66 | if (s == NULL || *s == '\0') |
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67 | return 0; |
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68 | if (n == 0) |
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69 | return -1; |
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70 | return 1; |
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71 | #endif /* not _MB_CAPABLE */ |
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72 | } |
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73 | |
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74 | #endif /* !_REENT_ONLY */ |
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