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1 /* |
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2 * Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: |
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15 * |
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16 */ |
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17 |
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18 |
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19 |
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20 #ifndef _SYS_STDIO_T_H_ |
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21 #define _SYS_STDIO_T_H_ |
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22 #ifdef __cplusplus |
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23 extern "C" { |
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24 #endif |
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25 |
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26 #include <_ansi.h> |
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27 |
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28 /** |
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29 Stdio buffers. |
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30 @publishedAll |
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31 @released |
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32 */ |
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33 struct __sbuf { |
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34 unsigned char * _base; |
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35 int _size; |
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36 }; |
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37 |
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38 /** |
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39 We need fpos_t for the following, but it doesn't have a leading "_", |
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40 so we use _fpos_t instead. |
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41 @publishedAll |
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42 @released |
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43 */ |
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44 |
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45 typedef long _fpos_t; /* XXX must match off_t in <sys/types.h> */ |
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46 /* (and must be `long' for now) */ |
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47 |
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48 /** |
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49 Stdio state variables. |
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50 |
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51 The following always hold: |
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52 |
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53 if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR), |
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54 _lbfsize is -_bf._size, else _lbfsize is 0 |
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55 if _flags&__SRD, _w is 0 |
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56 if _flags&__SWR, _r is 0 |
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57 |
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58 This ensures that the getc and putc macros (or inline functions) never |
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59 try to write or read from a file that is in `read' or `write' mode. |
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60 (Moreover, they can, and do, automatically switch from read mode to |
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61 write mode, and back, on "r+" and "w+" files.) |
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62 |
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63 _lbfsize is used only to make the inline line-buffered output stream |
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64 code as compact as possible. |
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65 |
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66 _ub, _up, and _ur are used when ungetc() pushes back more characters |
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67 than fit in the current _bf, or when ungetc() pushes back a character |
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68 that does not match the previous one in _bf. When this happens, |
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69 _ub._base becomes non-nil (i.e., a stream has ungetc() data iff |
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70 _ub._base!=NULL) and _up and _ur save the current values of _p and _r. |
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71 @publishedAll |
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72 @released |
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73 */ |
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74 struct __sFILE { |
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75 unsigned char *_p; /* current position in (some) buffer */ |
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76 int _r; /* read space left for getc() */ |
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77 int _w; /* write space left for putc() */ |
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78 short _flags; /* flags, below; this FILE is free if 0 */ |
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79 short _file; /* fileno, if Unix descriptor, else -1 */ |
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80 struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */ |
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81 int _lbfsize; /* 0 or -_bf._size, for inline putc */ |
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82 |
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83 /* operations */ |
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84 void * _cookie; /* cookie passed to io functions */ |
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85 |
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86 int (*_read) (void * _cookie, char *_buf, int _n); |
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87 int (*_write)(void * _cookie, const char *_buf, int _n); |
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88 _fpos_t (*_seek) (void * _cookie, _fpos_t _offset, int _whence); |
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89 int (*_close)(void * _cookie); |
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90 |
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91 /* separate buffer for long sequences of ungetc() */ |
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92 struct __sbuf _ub; /* ungetc buffer */ |
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93 unsigned char * _up; /* saved _p when _p is doing ungetc data */ |
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94 int _ur; /* saved _r when _r is counting ungetc data */ |
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95 |
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96 /* tricks to meet minimum requirements even when malloc() fails */ |
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97 unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */ |
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98 unsigned char _nbuf[1]; /* guarantee a getc() buffer */ |
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99 |
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100 /* separate buffer for fgetline() when line crosses buffer boundary */ |
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101 struct __sbuf _lb; /* buffer for fgetline() */ |
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102 |
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103 /* Unix stdio files get aligned to block boundaries on fseek() */ |
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104 int _blksize; /* stat.st_blksize (may be != _bf._size) */ |
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105 int _offset; /* current lseek offset */ |
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106 |
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107 struct _reent * _data; /* pointer back to re-entrancy context block */ |
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108 }; |
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109 |
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110 |
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111 #ifdef __cplusplus |
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112 } |
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113 #endif |
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114 #endif /* _SYS_STDIO_T_H_ */ |