ToDo Need to lean more on parport handler :
http://lwn.net/Articles/driver-porting/
cat > ./parport.c <<EOF
#include <stdio.h> #include <unistd.h> #include <asm/io.h>
#define PORT 0x378
char tmp=0;
int main() {
if ( ioperm( PORT,1,1)) { perror("no perms"); exit(-1); }
outb( tmp, PORT);
return 0;
}
EOF
# EOF for cat
make parport
./parport ; echo $? ## no perms: Operation not permitted ## 255
su -- chmod u+s ./parport ./parport ; echo $? ## 0