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outb.cc

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/*
  outb.c

  Set the value  of a x86 hardware port register.
  Parse command line, call outb(), and print result.

   Modification History:

   13-Jan-2000 WPS created.
*/


#ifndef linux

#include <stdio.h>
#include <stdlib.h>

int main()
{
  printf("outb doesn't work on this platform.\n");
  exit(-1);
}

#else

#include <unistd.h>
#include <sys/io.h>             // ioperm(), outb, inw outw
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>


int main(int argc, char **argv)
{
  unsigned long port;
  char val;

  if(argc < 2)
    {
      printf("usage: <port> <value>\n");
      exit(-1);
    }

  port = strtoul(argv[1],NULL,0);
  val = (char) strtol(argv[2],NULL,0);
  if(geteuid() && getuid())
    {
      printf("Must be root for this program to work.\n");
      exit(-1);
    }

  if(-1 == iopl(3))
    {
      printf("Can't set privaledge level.\n");
    }
  outb(port,val);
}
#endif

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