sysdeps/standalone/write.c

   1 /* Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.
   2    Ported to standalone by Joel Sherrill jsherril@redstone-emh2.army.mil,
   3      On-Line Applications Research Corporation.
   4
   5 This file is part of the GNU C Library.
   6
   7 The GNU C Library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public License as
   9 published by the Free Software Foundation; either version 2 of the
  10 License, or (at your option) any later version.
  11
  12 The GNU C Library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with the GNU C Library; see the file COPYING.LIB.  If
  19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20 Cambridge, MA 02139, USA.  */
  21
  22 #include <sysdep.h>
  23 #include <errno.h>
  24 #include <unistd.h>
  25 #include <stddef.h>
  26
  27 #include "filedesc.h"
  28 #include <fcntl.h>
  29 #include <standalone.h>
  30
  31 /* Write NBYTES of BUF to FD.  Return the number written, or -1.  */
  32 ssize_t
  33 __libc_write (int fd, const void *buf, size_t nbytes)
  34 {
  35   int count;
  36   const char *data = buf;
  37
  38   if (nbytes == 0)
  39     return 0;
  40   if ( !__FD_Is_valid( fd ) || !__FD_Table[ fd ].in_use )
  41     {
  42       __set_errno (EBADF);
  43       return -1;
  44     }
  45   if (buf == NULL)
  46     {
  47       __set_errno (EINVAL);
  48       return -1;
  49     }
  50
  51   if ( !(__FD_Table[ fd ].flags & (O_WRONLY|O_RDWR)) )  /* is it writeable? */
  52     {
  53       __set_errno (EBADF);
  54       return -1;
  55     }
  56
  57   /*
  58    *  All open file descriptors are mapped to the console.
  59    */
  60
  61   for ( count=0 ; count != nbytes ; count++ ) {
  62     if ( _Console_Putc(data[ count ]) == -1 )
  63       return -1;
  64     if ( data[count] == '\n' && _Console_Putc('\r') == -1 )
  65       return -1;
  66   }
  67
  68   return count;
  69 }
  70
  71 weak_alias (__libc_write, __write)
  72 weak_alias (__libc_write, write)