Messages in this thread | | | Date | Tue, 4 Mar 2003 23:31:52 +0100 (CET) | From | Eric Lammerts <> | Subject | Re: Direct access to parport |
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On Tue, 4 Mar 2003, Uwe Reimann wrote: > I'd like to connect some self made hardware to the parallel port and > read the values of the dataline using linux. Can this be done in > userspace or do I have to write kernel code to do so? I'm currently > thinking of writing a device like lp, which in turn uses the parport > device. Does this sound like a good idea?
From userspace it's quite simple:
#include <stdio.h> #include <sys/io.h>
int main(int argc, char **argv) { int addr = 0x378;
if(ioperm(addr, 3, 1) == -1) { perror("ioperm"); exit(1); } printf("0x%02x\n", inb(addr + 1)); }
The ioperm() only works if you're root.
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