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 | <<getc>>---read a character (macro) |
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21 | |
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22 | INDEX |
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23 | getc |
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24 | INDEX |
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25 | _getc_r |
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26 | |
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27 | SYNOPSIS |
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28 | #include <stdio.h> |
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29 | int getc(FILE *<[fp]>); |
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30 | |
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31 | #include <stdio.h> |
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32 | int _getc_r(struct _reent *<[ptr]>, FILE *<[fp]>); |
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33 | |
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34 | DESCRIPTION |
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35 | <<getc>> is a macro, defined in <<stdio.h>>. You can use <<getc>> |
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36 | to get the next single character from the file or stream |
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37 | identified by <[fp]>. As a side effect, <<getc>> advances the file's |
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38 | current position indicator. |
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39 | |
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40 | For a subroutine version of this macro, see <<fgetc>>. |
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41 | |
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42 | The <<_getc_r>> function is simply the reentrant version of <<getc>> |
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43 | which passes an additional reentrancy structure pointer argument: <[ptr]>. |
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44 | |
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45 | RETURNS |
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46 | The next character (read as an <<unsigned char>>, and cast to |
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47 | <<int>>), unless there is no more data, or the host system reports a |
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48 | read error; in either of these situations, <<getc>> returns <<EOF>>. |
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49 | |
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50 | You can distinguish the two situations that cause an <<EOF>> result by |
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51 | using the <<ferror>> and <<feof>> functions. |
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52 | |
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53 | PORTABILITY |
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54 | ANSI C requires <<getc>>; it suggests, but does not require, that |
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55 | <<getc>> be implemented as a macro. The standard explicitly permits |
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56 | macro implementations of <<getc>> to use the argument more than once; |
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57 | therefore, in a portable program, you should not use an expression |
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58 | with side effects as the <<getc>> argument. |
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59 | |
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60 | Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, |
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61 | <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |
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62 | */ |
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63 | |
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64 | #if defined(LIBC_SCCS) && !defined(lint) |
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65 | static char sccsid[] = "%W% (Berkeley) %G%"; |
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66 | #endif /* LIBC_SCCS and not lint */ |
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67 | |
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68 | #include <_ansi.h> |
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69 | #include <stdio.h> |
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70 | #include "local.h" |
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71 | |
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72 | /* |
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73 | * A subroutine version of the macro getc. |
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74 | */ |
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75 | |
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76 | #undef getc |
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77 | |
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78 | int |
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79 | _getc_r (struct _reent *ptr, |
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80 | register FILE *fp) |
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81 | { |
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82 | int result; |
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83 | CHECK_INIT (ptr, fp); |
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84 | _newlib_flockfile_start (fp); |
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85 | result = __sgetc_r (ptr, fp); |
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86 | _newlib_flockfile_end (fp); |
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87 | return result; |
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88 | } |
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89 | |
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90 | #ifndef _REENT_ONLY |
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91 | |
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92 | int |
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93 | getc (register FILE *fp) |
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94 | { |
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95 | int result; |
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96 | struct _reent *reent = _REENT; |
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97 | |
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98 | CHECK_INIT (reent, fp); |
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99 | _newlib_flockfile_start (fp); |
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100 | result = __sgetc_r (reent, fp); |
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101 | _newlib_flockfile_end (fp); |
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102 | return result; |
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103 | } |
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104 | |
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105 | #endif /* !_REENT_ONLY */ |
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