Print /dev/input/event* device node in debug output.

1 files changed, 16 insertions, 0 deletions

diff --git a/marsond.c b/marsond.c
index 8070d78..d85673c 100644
--- a/marsond.c
+++ b/marsond.c
@@ -11,6 +11,7 @@
 #include <pwd.h>
 #include <grp.h>
 #include <signal.h>
+#include <limits.h>
 
 #include <sys/resource.h>
 #include <sys/mman.h>
@@ -293,6 +294,18 @@ void set_evbit(int outfd, int event) {
 	}
 }
 
+void get_device_node(char *result) {
+	char path[PATH_MAX];
+
+	/* trick here: outfd is the last file we opened. while running, we
+	   have an open file descriptor for the virtual device, which *must*
+	   be the next integer file descriptor after outfd. */
+	snprintf(path, PATH_MAX - 1, "/proc/%d/fd/%d", getpid(), outfd + 1);
+
+	if(readlink(path, result, UINPUT_MAX_NAME_SIZE - 1) < 0)
+		strcpy(result, "(unknown)");
+}
+
 void print_device_name(void) {
 	char name[UINPUT_MAX_NAME_SIZE];
 
@@ -301,6 +314,9 @@ void print_device_name(void) {
 	} else {
 		debug("created virtual keyboard device but couldn't get its name (old kernel?)");
 	}
+
+	get_device_node(name);
+	debug("device node: %s", name);
 }
 
 int main(int argc, char **argv) {