stdio/getc.3

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  36 .\"     @(#)getc.3      8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/stdio/getc.3,v 1.11 2001/10/01 16:08:59 ru Exp $
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  39 .Dd June 4, 1993
  40 .Dt GETC 3
  41 .Os
  42 .Sh NAME
  43 .Nm fgetc ,
  44 .Nm getc ,
  45 .Nm getchar ,
  46 .Nm getw
  47 .Nd get next character or word from input stream
  48 .Sh LIBRARY
  49 .Lb libc
  50 .Sh SYNOPSIS
  51 .In stdio.h
  52 .Ft int
  53 .Fn fgetc "FILE *stream"
  54 .Ft int
  55 .Fn getc "FILE *stream"
  56 .Ft int
  57 .Fn getchar
  58 .Ft int
  59 .Fn getw "FILE *stream"
  60 .Sh DESCRIPTION
  61 The
  62 .Fn fgetc
  63 function
  64 obtains the next input character (if present) from the stream pointed at by
  65 .Fa stream ,
  66 or the next character pushed back on the stream via
  67 .Xr ungetc 3 .
  68 .Pp
  69 The
  70 .Fn getc
  71 function
  72 acts essentially identically to
  73 .Fn fgetc ,
  74 but is a macro that expands in-line.
  75 .Pp
  76 The
  77 .Fn getchar
  78 function
  79 is equivalent to
  80 .Fn getc stdin .
  81 .Pp
  82 The
  83 .Fn getw
  84 function
  85 obtains the next
  86 .Em int
  87 (if present)
  88 from the stream pointed at by
  89 .Fa stream .
  90 .Sh RETURN VALUES
  91 If successful, these routines return the next requested object
  92 from the
  93 .Fa stream .
  94 If the stream is at end-of-file or a read error occurs,
  95 the routines return
  96 .Dv EOF .
  97 The routines
  98 .Xr feof 3
  99 and
 100 .Xr ferror 3
 101 must be used to distinguish between end-of-file and error.
 102 If an error occurs, the global variable
 103 .Va errno
 104 is set to indicate the error.
 105 The end-of-file condition is remembered, even on a terminal, and all
 106 subsequent attempts to read will return
 107 .Dv EOF
 108 until the condition is cleared with
 109 .Xr clearerr 3 .
 110 .Sh SEE ALSO
 111 .Xr ferror 3 ,
 112 .Xr fopen 3 ,
 113 .Xr fread 3 ,
 114 .Xr putc 3 ,
 115 .Xr ungetc 3
 116 .Sh STANDARDS
 117 The
 118 .Fn fgetc ,
 119 .Fn getc
 120 and
 121 .Fn getchar
 122 functions
 123 conform to
 124 .St -isoC .
 125 .Sh BUGS
 126 Since
 127 .Dv EOF
 128 is a valid integer value,
 129 .Xr feof 3
 130 and
 131 .Xr ferror 3
 132 must be used to check for failure after calling
 133 .Fn getw .
 134 The size and byte order of an
 135 .Em int
 136 varies from one machine to another, and
 137 .Fn getw
 138 is not recommended for portable applications.
 139 .Pp