udev - introduce format escape char

This patch adds a '%' to the format char list, so that a external program may called with a non expanded '%' like:

PROGRAM="/bin/date +%%s"

Olaf Hering asked for the feature.
A tricky test is also added :)

thanks,
Kay

diff -Nru a/namedev.c b/namedev.c
@@ -151,20 +151,21 @@
 
 static void apply_format(struct udevice *udev, unsigned char *string)
 {
-	char name[NAME_SIZE];
 	char temp[NAME_SIZE];
+	char temp1[NAME_SIZE];
 	char *tail;
 	char *pos;
 	char *pos2;
 	char *pos3;
 	int num;
 
+	pos = string;
 	while (1) {
 		num = 0;
-		pos = strchr(string, '%');
+		pos = strchr(pos, '%');
 
 		if (pos) {
-			*pos = '\0';
+			pos[0] = '\0';
 			tail = pos+1;
 			if (isdigit(tail[0])) {
 				num = (int) strtoul(&pos[1], &tail, 10);

@@ -173,7 +174,7 @@
 					break;
 				}
 			}
-			strfieldcpy(name, tail+1);
+			strfieldcpy(temp, tail+1);
 
 			switch (tail[0]) {
 			case 'b':

@@ -217,8 +218,8 @@
 					break;
 				if (num) {
 					/* get part of return string */
-					strncpy(temp, udev->program_result, sizeof(temp));
-					pos2 = temp;
+					strncpy(temp1, udev->program_result, sizeof(temp1));
+					pos2 = temp1;
 					while (num) {
 						num--;
 						pos3 = strsep(&pos2, " ");

@@ -236,11 +237,15 @@
 					dbg("substitute result string '%s'", udev->program_result);
 				}
 				break;
+			case '%':
+				strcat(pos, "%");
+				pos++;
+				break;
 			default:
 				dbg("unknown substitution type '%%%c'", pos[1]);
 				break;
 			}
-			strcat(string, name);
+			strcat(string, temp);
 		} else
 			break;
 	}

diff -Nru a/test/udev-test.pl b/test/udev-test.pl
@@ -206,6 +206,15 @@
 EOF
 	},
 	{
+		desc     => "program with escaped format char (tricky: callout returns format char!)",
+		subsys   => "block",
+		devpath  => "block/sda/sda3",
+		expected => "escape-3" ,
+		conf     => <<EOF
+BUS="scsi", PROGRAM="/bin/echo -n escape-%%n", KERNEL="sda3", NAME="%c"
+EOF
+	},
+	{
 		desc     => "program result substitution (numbered part of)",
 		subsys   => "block",
 		devpath  => "block/sda/sda3",

Hm, does this mean that we can't pass a "%n" to a program as it is something we intrepret (your test seems to verify this)?

Is that ok?

Anyway, I've applied this.

thanks,

greg k-h

-------------------------------------------------------
This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html
_______________________________________________
Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

No, it wasn't possible before. That's why we have the escape now. If you want to pass any '%' down to a program, you need to ecape it by '%%', otherwise we try to expand it with our own format char list.

I will put in the man page, later today.

In my stupid test, the program returns a '%n' and this is expanded inside the '%c' to the kernel number. I found it funny... :)

thanks,
Kay

-------------------------------------------------------
This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html
_______________________________________________
Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Ah, that makes more sense now, thanks.

I need to wake up today...

greg k-h

-------------------------------------------------------
This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html
_______________________________________________
Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel