toolchain/gcc/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  * advertising materials, and 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
  25 ANSI_SYNOPSIS
  26         #include <stdio.h>
  27         int putc(int <[ch]>, FILE *<[fp]>);
  28
  29 TRAD_SYNOPSIS
  30         #include <stdio.h>
  31         int putc(<[ch]>, <[fp]>)
  32         int <[ch]>;
  33         FILE *<[fp]>;
  34
  35 DESCRIPTION
  36 <<putc>> is a macro, defined in <<stdio.h>>.  <<putc>>
  37 writes the argument <[ch]> to the file or stream identified by
  38 <[fp]>, after converting it from an <<int>> to an <<unsigned char>>.
  39
  40 If the file was opened with append mode (or if the stream cannot
  41 support positioning), then the new character goes at the end of the
  42 file or stream.  Otherwise, the new character is written at the
  43 current value of the position indicator, and the position indicator
  44 advances by one.
  45
  46 For a subroutine version of this macro, see <<fputc>>.
  47
  48 RETURNS
  49 If successful, <<putc>> returns its argument <[ch]>.  If an error
  50 intervenes, the result is <<EOF>>.  You can use `<<ferror(<[fp]>)>>' to
  51 query for errors.
  52
  53 PORTABILITY
  54 ANSI C requires <<putc>>; it suggests, but does not require, that
  55 <<putc>> be implemented as a macro.  The standard explicitly permits
  56 macro implementations of <<putc>> to use the <[fp]> argument more than once;
  57 therefore, in a portable program, you should not use an expression
  58 with side effects as this argument.
  59
  60 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
  61 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
  62 */
  63
  64 #if defined(LIBC_SCCS) && !defined(lint)
  65 static char sccsid[] = "%W% (Berkeley) %G%";
  66 #endif /* LIBC_SCCS and not lint */
  67
  68 #include <stdio.h>
  69
  70 /*
  71  * A subroutine version of the macro putc.
  72  */
  73
  74 #undef putc
  75
  76 int
  77 putc (c, fp)
  78      int c;
  79      register FILE *fp;
  80 {
  81   int result;
  82   _flockfile(fp);
  83   /* CHECK_INIT is (eventually) called by __swbuf.  */
  84   result = __sputc (c, fp);
  85   _funlockfile(fp);
  86   return result;
  87 }