glibc/sysdeps/standalone/write.c

/* Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
   Ported to standalone by Joel Sherrill jsherril@redstone-emh2.army.mil,
     On-Line Applications Research Corporation.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include <errno.h>
#include <unistd.h>
#include <stddef.h>

#include "filedesc.h"
#include <fcntl.h>
#include <standalone.h>

/* Write NBYTES of BUF to FD.  Return the number written, or -1.  */
ssize_t
__libc_write (int fd, const void *buf, size_t nbytes)
{
  int count;
  const char *data = buf;

  if (nbytes == 0)
    return 0;
  if ( !__FD_Is_valid( fd ) || !__FD_Table[ fd ].in_use )
    {
      __set_errno (EBADF);
      return -1;
    }
  if (buf == NULL)
    {
      __set_errno (EINVAL);
      return -1;
    }

  if ( !(__FD_Table[ fd ].flags & (O_WRONLY|O_RDWR)) )  /* is it writeable? */
    {
      __set_errno (EBADF);
      return -1;
    }

  /*
   *  All open file descriptors are mapped to the console.
   */

  for ( count=0 ; count != nbytes ; count++ ) {
    if ( _Console_Putc(data[ count ]) == -1 )
      return -1;
    if ( data[count] == '\n' && _Console_Putc('\r') == -1 )
      return -1;
  }

  return count;
}

weak_alias (__libc_write, __write)
weak_alias (__libc_write, write)