text: /*
    ledtst.c: User program to use the Linux driver for a LED on IO13
    
    Copyright (c) 2016 Walter Fetter Lages <w.fetter@ieee.org>
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program 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 General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  
      You can also obtain a copy of the GNU General Public License
      at <http://www.gnu.org/licenses>.
  
  */
  
  #include <errno.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  
  int main(int argc,char *argv[])
  {
  	int fd;
  	
  	if(argc != 3)
  	{
  		fprintf(stderr,"ledtst\n");
  		fprintf(stderr,"\tUsage:\t%s <device> <value>\n",argv[0]);
  		return -1;
  	}
  	if((fd=open(argv[1],O_WRONLY))==-1)
  	{
  		perror("ledtst");
  		return -errno;
  	}
  	
  	if(write(fd,&argv[2][0],1)==-1)
  	{
  		perror("ledtst");
  		return -errno;
  	}
  	
  	sleep(5);
  	
  	if(close(fd))
  	{
  		perror("ledtst");
  		return -errno;
  	}
  	
  	return 0;
  }
  