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/*
* Simple command interface to ioctl(fd, LPSETIRQ, irq).
* Nigel Gamble (nigel@gate.net)
* e.g.
* lpcntl /dev/lp1 7
*/
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <linux/lp.h>
int
main(int argc, char **argv)
{
unsigned int irq;
int fd;
int ret;
if (argc < 2) {
fprintf(stderr, "usage: %s <lp device> [<irq>]\n", argv[0]);
exit(1);
}
fd = open(argv[1], O_RDONLY);
if (fd == -1) {
perror(argv[1]);
exit(1);
}
if (argc == 2) {
irq = ioctl(fd, LPGETIRQ);
if (irq == -1) {
perror(argv[1]);
exit(1);
}
if (irq)
printf("%s using IRQ %d\n", argv[1], irq);
else
printf("%s using polling\n", argv[1]);
} else {
irq = atoi(argv[2]);
ret = ioctl(fd, LPSETIRQ, irq);
if (ret == -1) {
if (errno == EPERM)
fprintf(stderr, "%s: only super-user can change the IRQ\n", argv[0]);
else
perror(argv[1]);
exit(1);
}
}
return 0;
}
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