sysdeps/standalone/write.c

   1 /* Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
   2    Ported to standalone by Joel Sherrill jsherril@redstone-emh2.army.mil,
   3      On-Line Applications Research Corporation.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <sysdep.h>
  22 #include <errno.h>
  23 #include <unistd.h>
  24 #include <stddef.h>
  25
  26 #include "filedesc.h"
  27 #include <fcntl.h>
  28 #include <standalone.h>
  29
  30 /* Write NBYTES of BUF to FD.  Return the number written, or -1.  */
  31 ssize_t
  32 __libc_write (int fd, const void *buf, size_t nbytes)
  33 {
  34   int count;
  35   const char *data = buf;
  36
  37   if (nbytes == 0)
  38     return 0;
  39   if ( !__FD_Is_valid( fd ) || !__FD_Table[ fd ].in_use )
  40     {
  41       __set_errno (EBADF);
  42       return -1;
  43     }
  44   if (buf == NULL)
  45     {
  46       __set_errno (EINVAL);
  47       return -1;
  48     }
  49
  50   if ( !(__FD_Table[ fd ].flags & (O_WRONLY|O_RDWR)) )  /* is it writeable? */
  51     {
  52       __set_errno (EBADF);
  53       return -1;
  54     }
  55
  56   /*
  57    *  All open file descriptors are mapped to the console.
  58    */
  59
  60   for ( count=0 ; count != nbytes ; count++ ) {
  61     if ( _Console_Putc(data[ count ]) == -1 )
  62       return -1;
  63     if ( data[count] == '\n' && _Console_Putc('\r') == -1 )
  64       return -1;
  65   }
  66
  67   return count;
  68 }
  69
  70 weak_alias (__libc_write, __write)
  71 weak_alias (__libc_write, write)