1 files changed, 54 insertions, 0 deletions
diff --git a/sys-utils/lpcntl.c b/sys-utils/lpcntl.c
new file mode 100644
index 000000000..bf164a632
--- /dev/null
+++ b/sys-utils/lpcntl.c
@@ -0,0 +1,54 @@
+/*
+ * 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;
+}