1 | /* |
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2 | * Copyright (c) 1990 The Regents of the University of California. |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms are permitted |
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6 | * provided that the above copyright notice and this paragraph are |
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7 | * duplicated in all such forms and that any documentation, |
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8 | * advertising materials, and other materials related to such |
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9 | * distribution and use acknowledge that the software was developed |
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10 | * by the University of California, Berkeley. The name of the |
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11 | * University may not be used to endorse or promote products derived |
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12 | * from this software without specific prior written permission. |
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13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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16 | */ |
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17 | |
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18 | /* |
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19 | FUNCTION |
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20 | <<fgetc>>, <<fgetc_unlocked>>---get a character from a file or stream |
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21 | |
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22 | INDEX |
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23 | fgetc |
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24 | INDEX |
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25 | fgetc_unlocked |
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26 | INDEX |
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27 | _fgetc_r |
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28 | INDEX |
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29 | _fgetc_unlocked_r |
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30 | |
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31 | SYNOPSIS |
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32 | #include <stdio.h> |
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33 | int fgetc(FILE *<[fp]>); |
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34 | |
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35 | #define _BSD_SOURCE |
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36 | #include <stdio.h> |
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37 | int fgetc_unlocked(FILE *<[fp]>); |
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38 | |
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39 | #include <stdio.h> |
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40 | int _fgetc_r(struct _reent *<[ptr]>, FILE *<[fp]>); |
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41 | |
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42 | #define _BSD_SOURCE |
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43 | #include <stdio.h> |
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44 | int _fgetc_unlocked_r(struct _reent *<[ptr]>, FILE *<[fp]>); |
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45 | |
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46 | DESCRIPTION |
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47 | Use <<fgetc>> to get the next single character from the file or stream |
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48 | identified by <[fp]>. As a side effect, <<fgetc>> advances the file's |
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49 | current position indicator. |
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50 | |
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51 | For a macro version of this function, see <<getc>>. |
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52 | |
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53 | <<fgetc_unlocked>> is a non-thread-safe version of <<fgetc>>. |
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54 | <<fgetc_unlocked>> may only safely be used within a scope |
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55 | protected by flockfile() (or ftrylockfile()) and funlockfile(). This |
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56 | function may safely be used in a multi-threaded program if and only |
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57 | if they are called while the invoking thread owns the (FILE *) |
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58 | object, as is the case after a successful call to the flockfile() or |
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59 | ftrylockfile() functions. If threads are disabled, then |
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60 | <<fgetc_unlocked>> is equivalent to <<fgetc>>. |
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61 | |
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62 | The functions <<_fgetc_r>> and <<_fgetc_unlocked_r>> are simply reentrant |
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63 | versions that are passed the additional reentrant structure pointer |
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64 | argument: <[ptr]>. |
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65 | |
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66 | RETURNS |
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67 | The next character (read as an <<unsigned char>>, and cast to |
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68 | <<int>>), unless there is no more data, or the host system reports a |
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69 | read error; in either of these situations, <<fgetc>> returns <<EOF>>. |
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70 | |
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71 | You can distinguish the two situations that cause an <<EOF>> result by |
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72 | using the <<ferror>> and <<feof>> functions. |
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73 | |
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74 | PORTABILITY |
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75 | ANSI C requires <<fgetc>>. |
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76 | |
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77 | <<fgetc_unlocked>> is a BSD extension also provided by GNU libc. |
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78 | |
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79 | Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, |
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80 | <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |
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81 | */ |
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82 | |
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83 | #include <_ansi.h> |
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84 | #include <stdio.h> |
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85 | #include "local.h" |
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86 | |
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87 | int |
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88 | _fgetc_r (struct _reent * ptr, |
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89 | FILE * fp) |
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90 | { |
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91 | int result; |
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92 | CHECK_INIT(ptr, fp); |
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93 | _newlib_flockfile_start (fp); |
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94 | result = __sgetc_r (ptr, fp); |
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95 | _newlib_flockfile_end (fp); |
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96 | return result; |
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97 | } |
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98 | |
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99 | #ifndef _REENT_ONLY |
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100 | |
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101 | int |
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102 | fgetc (FILE * fp) |
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103 | { |
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104 | #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
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105 | int result; |
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106 | struct _reent *reent = _REENT; |
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107 | |
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108 | CHECK_INIT(reent, fp); |
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109 | _newlib_flockfile_start (fp); |
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110 | result = __sgetc_r (reent, fp); |
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111 | _newlib_flockfile_end (fp); |
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112 | return result; |
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113 | #else |
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114 | return _fgetc_r (_REENT, fp); |
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115 | #endif |
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116 | } |
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117 | |
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118 | #endif /* !_REENT_ONLY */ |
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119 | |
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