X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevmonitor.c;h=2775b295ceac9bc18e709d77e6660dce23655612;hp=3a71d002f562377aad741d514dfd57c22f6640fa;hb=c907c823c388dfbdfa7054cfb2f4e9b92eb31e2e;hpb=d33c51c24531b602c9f45a8914c6b1db82c003ec

diff --git a/udevmonitor.c b/udevmonitor.c
index 3a71d002f..2775b295c 100644
--- a/udevmonitor.c
+++ b/udevmonitor.c
@@ -33,6 +33,7 @@
 
 #include "udev.h"
 #include "udevd.h"
+#include "udev_utils.h"
 #include "udev_libc_wrapper.h"
 
 static int uevent_netlink_sock;
@@ -102,42 +103,59 @@ static int init_uevent_netlink_sock(void)
 int main(int argc, char *argv[])
 {
 	int env = 0;
-	int maxsockplus;
 	fd_set readfds;
-	int retval;
+	int i;
+	int retval = 0;
+
+	for (i = 1 ; i < argc; i++) {
+		char *arg = argv[i];
+		if (strcmp(arg, "--env") == 0 || strcmp(arg, "-e") == 0) {
+			env = 1;
+		}
+		else if (strcmp(arg, "--help") == 0  || strcmp(arg, "-h") == 0){
+			printf("Usage: udevmonitor [--env]\n"
+				"  --env    print the whole event environment\n"
+				"  --help   print this help text\n\n");
+			exit(0);
+		} else {
+			fprintf(stderr, "unknown option\n\n");
+			exit(1);
+		}
+	}
 
 	if (getuid() != 0) {
-		printf("need to be root, exit\n");
+		fprintf(stderr, "need to be root, exit\n\n");
 		exit(1);
 	}
 
-	if (argc == 2 && strstr(argv[1], "--env"))
-		env = 1;
-
+	retval = init_udev_monitor_socket();
+	if (retval)
+		goto out;
 	init_uevent_netlink_sock();
-	init_udev_monitor_socket();
 
-	FD_ZERO(&readfds);
-	FD_SET(uevent_netlink_sock, &readfds);
-	FD_SET(udev_monitor_sock, &readfds);
-	maxsockplus = udev_monitor_sock+1;
+	printf("udevmonitor prints the received event from the kernel [UEVENT]\n"
+	       "and the event which udev sends out after rule processing [UDEV]\n\n");
 
 	while (1) {
 		static char buf[UEVENT_BUFFER_SIZE*2];
 		ssize_t buflen;
-		fd_set workreadfds;
+		int fdcount;
 
 		buflen = 0;
-		workreadfds = readfds;
-
-		retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL);
-		if (retval < 0) {
+		FD_ZERO(&readfds);
+		if (uevent_netlink_sock > 0)
+			FD_SET(uevent_netlink_sock, &readfds);
+		if (udev_monitor_sock > 0)
+			FD_SET(udev_monitor_sock, &readfds);
+
+		fdcount = select(UDEV_MAX(uevent_netlink_sock, udev_monitor_sock)+1, &readfds, NULL, NULL, NULL);
+		if (fdcount < 0) {
 			if (errno != EINTR)
 				fprintf(stderr, "error receiving uevent message\n");
 			continue;
 		}
 
-		if (FD_ISSET(uevent_netlink_sock, &workreadfds)) {
+		if ((uevent_netlink_sock > 0) && FD_ISSET(uevent_netlink_sock, &readfds)) {
 			buflen = recv(uevent_netlink_sock, &buf, sizeof(buf), 0);
 			if (buflen <=  0) {
 				fprintf(stderr, "error receiving uevent message\n");
@@ -146,7 +164,7 @@ int main(int argc, char *argv[])
 			printf("UEVENT[%i] %s\n", time(NULL), buf);
 		}
 
-		if (FD_ISSET(udev_monitor_sock, &workreadfds)) {
+		if ((udev_monitor_sock > 0) && FD_ISSET(udev_monitor_sock, &readfds)) {
 			buflen = recv(udev_monitor_sock, &buf, sizeof(buf), 0);
 			if (buflen <=  0) {
 				fprintf(stderr, "error receiving udev message\n");
@@ -180,7 +198,11 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	close(uevent_netlink_sock);
-	close(udev_monitor_sock);
-	exit(1);
+out:
+	if (uevent_netlink_sock > 0)
+		close(uevent_netlink_sock);
+	if (udev_monitor_sock > 0)
+		close(udev_monitor_sock);
+
+	return retval;
 }