1 | /* |
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2 | FUNCTION |
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3 | <<fwide>>---set and determine the orientation of a FILE stream |
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4 | |
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5 | INDEX |
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6 | fwide |
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7 | INDEX |
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8 | _fwide_r |
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9 | |
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10 | SYNOPSIS |
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11 | #include <wchar.h> |
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12 | int fwide(FILE *<[fp]>, int <[mode]>); |
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13 | |
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14 | int _fwide_r(struct _reent *<[ptr]>, FILE *<[fp]>, int <[mode]>); |
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15 | |
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16 | DESCRIPTION |
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17 | When <[mode]> is zero, the <<fwide>> function determines the current |
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18 | orientation of <[fp]>. It returns a value > 0 if <[fp]> is |
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19 | wide-character oriented, i.e. if wide character I/O is permitted but |
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20 | char I/O is disallowed. It returns a value < 0 if <[fp]> is byte |
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21 | oriented, i.e. if char I/O is permitted but wide character I/O is |
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22 | disallowed. It returns zero if <[fp]> has no orientation yet; in |
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23 | this case the next I/O operation might change the orientation (to byte |
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24 | oriented if it is a char I/O operation, or to wide-character oriented |
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25 | if it is a wide character I/O operation). |
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26 | |
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27 | Once a stream has an orientation, it cannot be changed and persists |
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28 | until the stream is closed, unless the stream is re-opened with freopen, |
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29 | which removes the orientation of the stream. |
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30 | |
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31 | When <[mode]> is non-zero, the <<fwide>> function first attempts to set |
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32 | <[fp]>'s orientation (to wide-character oriented if <[mode]> > 0, or to |
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33 | byte oriented if <[mode]> < 0). It then returns a value denoting the |
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34 | current orientation, as above. |
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35 | |
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36 | RETURNS |
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37 | The <<fwide>> function returns <[fp]>'s orientation, after possibly |
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38 | changing it. A return value > 0 means wide-character oriented. A return |
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39 | value < 0 means byte oriented. A return value of zero means undecided. |
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40 | |
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41 | PORTABILITY |
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42 | C99, POSIX.1-2001. |
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43 | |
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44 | */ |
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45 | |
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46 | #include <_ansi.h> |
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47 | #include <wchar.h> |
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48 | #include "local.h" |
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49 | |
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50 | int |
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51 | _fwide_r (struct _reent *ptr, |
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52 | FILE *fp, |
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53 | int mode) |
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54 | { |
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55 | int ret; |
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56 | |
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57 | CHECK_INIT(ptr, fp); |
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58 | |
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59 | _newlib_flockfile_start (fp); |
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60 | if (mode != 0) { |
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61 | ORIENT (fp, mode); |
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62 | } |
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63 | if (!(fp->_flags & __SORD)) |
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64 | ret = 0; |
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65 | else |
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66 | ret = (fp->_flags2 & __SWID) ? 1 : -1; |
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67 | _newlib_flockfile_end (fp); |
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68 | return ret; |
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69 | } |
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70 | |
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71 | int |
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72 | fwide (FILE *fp, |
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73 | int mode) |
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74 | { |
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75 | return _fwide_r (_REENT, fp, mode); |
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76 | } |
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