Back to index

glibc  2.9
write.c
Go to the documentation of this file.
00001 /* Copyright (C) 1994, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
00002    Ported to standalone by Joel Sherrill jsherril@redstone-emh2.army.mil,
00003      On-Line Applications Research Corporation.
00004    This file is part of the GNU C Library.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #include <sysdep.h>
00022 #include <errno.h>
00023 #include <unistd.h>
00024 #include <stddef.h>
00025 
00026 #include "filedesc.h"
00027 #include <fcntl.h>
00028 #include <standalone.h>
00029 
00030 /* Write NBYTES of BUF to FD.  Return the number written, or -1.  */
00031 ssize_t
00032 __libc_write (int fd, const void *buf, size_t nbytes)
00033 {
00034   int count;
00035   const char *data = buf;
00036 
00037   if (nbytes == 0)
00038     return 0;
00039   if ( !__FD_Is_valid( fd ) || !__FD_Table[ fd ].in_use )
00040     {
00041       __set_errno (EBADF);
00042       return -1;
00043     }
00044   if (buf == NULL)
00045     {
00046       __set_errno (EINVAL);
00047       return -1;
00048     }
00049 
00050   if ( !(__FD_Table[ fd ].flags & (O_WRONLY|O_RDWR)) )  /* is it writeable? */
00051     {
00052       __set_errno (EBADF);
00053       return -1;
00054     }
00055 
00056   /*
00057    *  All open file descriptors are mapped to the console.
00058    */
00059 
00060   for ( count=0 ; count != nbytes ; count++ ) {
00061     if ( _Console_Putc(data[ count ]) == -1 )
00062       return -1;
00063     if ( data[count] == '\n' && _Console_Putc('\r') == -1 )
00064       return -1;
00065   }
00066 
00067   return count;
00068 }
00069 
00070 libc_hidden_def (__libc_write)
00071 weak_alias (__libc_write, __write)
00072 libc_hidden_weak (__write)
00073 weak_alias (__libc_write, write)