newlib/libc/stdio/putc.c

   1 /*
   2  * Copyright (c) 1990 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * and/or other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Berkeley.  The name of the
  11  * University may not be used to endorse or promote products derived
  12  * from this software without specific prior written permission.
  13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16  */
  17
  18 /*
  19 FUNCTION
  20 <<putc>>---write a character (macro)
  21
  22 INDEX
  23         putc
  24 INDEX
  25         _putc_r
  26
  27 SYNOPSIS
  28         #include <stdio.h>
  29         int putc(int <[ch]>, FILE *<[fp]>);
  30
  31         #include <stdio.h>
  32         int _putc_r(struct _reent *<[ptr]>, int <[ch]>, FILE *<[fp]>);
  33
  34 DESCRIPTION
  35 <<putc>> is a macro, defined in <<stdio.h>>.  <<putc>>
  36 writes the argument <[ch]> to the file or stream identified by
  37 <[fp]>, after converting it from an <<int>> to an <<unsigned char>>.
  38
  39 If the file was opened with append mode (or if the stream cannot
  40 support positioning), then the new character goes at the end of the
  41 file or stream.  Otherwise, the new character is written at the
  42 current value of the position indicator, and the position indicator
  43 advances by one.
  44
  45 For a subroutine version of this macro, see <<fputc>>.
  46
  47 The <<_putc_r>> function is simply the reentrant version of
  48 <<putc>> that takes an additional reentrant structure argument: <[ptr]>.
  49
  50 RETURNS
  51 If successful, <<putc>> returns its argument <[ch]>.  If an error
  52 intervenes, the result is <<EOF>>.  You can use `<<ferror(<[fp]>)>>' to
  53 query for errors.
  54
  55 PORTABILITY
  56 ANSI C requires <<putc>>; it suggests, but does not require, that
  57 <<putc>> be implemented as a macro.  The standard explicitly permits
  58 macro implementations of <<putc>> to use the <[fp]> argument more than once;
  59 therefore, in a portable program, you should not use an expression
  60 with side effects as this argument.
  61
  62 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
  63 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
  64 */
  65
  66 #if defined(LIBC_SCCS) && !defined(lint)
  67 static char sccsid[] = "%W% (Berkeley) %G%";
  68 #endif /* LIBC_SCCS and not lint */
  69
  70 #include <_ansi.h>
  71 #include <stdio.h>
  72 #include "local.h"
  73
  74 /*
  75  * A subroutine version of the macro putc.
  76  */
  77
  78 #undef putc
  79
  80 int
  81 _putc_r (struct _reent *ptr,
  82        int c,
  83        register FILE *fp)
  84 {
  85   int result;
  86   CHECK_INIT (ptr, fp);
  87   _newlib_flockfile_start (fp);
  88   result = __sputc_r (ptr, c, fp);
  89   _newlib_flockfile_end (fp);
  90   return result;
  91 }
  92
  93 #ifndef _REENT_ONLY
  94 int
  95 putc (int c,
  96        register FILE *fp)
  97 {
  98 #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
  99   int result;
 100   struct _reent *reent = _REENT;
 101
 102   CHECK_INIT (reent, fp);
 103   _newlib_flockfile_start (fp);
 104   result = __sputc_r (reent, c, fp);
 105   _newlib_flockfile_end (fp);
 106   return result;
 107 #else
 108   return _putc_r (_REENT, c, fp);
 109 #endif
 110 }
 111 #endif /* !_REENT_ONLY */
 112