From 63ead27c228f9306f175b14a49df2415d09ece10 Mon Sep 17 00:00:00 2001
From: "kay.sievers@vrfy.org" <kay.sievers@vrfy.org>
Date: Sat, 28 Feb 2004 06:53:25 -0800
Subject: [PATCH] [PATCH] udev - activate formt length attribute

We carried the the old callout part selector syntax for two releases
now after it was replaced by the new %c{1} syntax. So here we remove
the old syntax and use the code to possibly specify the maximum count
of chars to insert into the string. It will work with all of our format
chars.
I don't know if somebody will use it, but the code is already there :)

's%3s{vendor}' returns "IBM" now, instead of "IBM-ESXS".

Also added is a test for it and a few words in the man page.
---
 namedev.c         | 10 +++++++---
 test/udev-test.pl |  9 +++++++++
 udev.8            |  8 ++++++--
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/namedev.c b/namedev.c
index c9232fa2..50526455 100644
--- a/namedev.c
+++ b/namedev.c
@@ -220,7 +220,7 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 	char *pos2;
 	char *pos3;
 	char *attr;
-	int num;
+	int len;
 	int i;
 	char c;
 	struct sysfs_attribute *tmpattr;
@@ -232,7 +232,7 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 		if (pos != NULL) {
 			pos[0] = '\0';
 			tail = pos+1;
-			num = get_format_len(&tail);
+			len = get_format_len(&tail);
 			c = tail[0];
 			strfieldcpy(temp, tail+1);
 			tail = temp;
@@ -274,7 +274,7 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 			if (strlen(udev->program_result) == 0)
 				break;
 			/* get part part of the result string */
-			i = num; /* num syntax is deprecated and will be removed  */
+			i = 0;
 			if (attr != NULL)
 				i = atoi(attr);
 			if (i > 0) {
@@ -317,6 +317,10 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 			dbg("unknown substitution type '%%%c'", c);
 			break;
 		}
+		/* truncate to specified length */
+		if (len > 0)
+			pos[len] = '\0';
+
 		strnfieldcat(string, tail, maxsize);
 	}
 }
diff --git a/test/udev-test.pl b/test/udev-test.pl
index a3bf768f..6b7f5154 100644
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -191,6 +191,15 @@ EOF
 		expected => "Major:8:minor:3:kernelnumber:3:bus:0:0:0:0" ,
 		conf     => <<EOF
 BUS="scsi", PLACE="0:0:0:0", NAME="Major:%M:minor:%m:kernelnumber:%n:bus:%b"
+EOF
+	},
+	{
+		desc     => "test NAME substitution chars (with length limit)",
+		subsys   => "block",
+		devpath  => "block/sda/sda3",
+		expected => "M8-m3-n3-b0:0-sIBM" ,
+		conf     => <<EOF
+BUS="scsi", PLACE="0:0:0:0", NAME="M%M-m%m-n%n-b%3b-s%3s{vendor}"
 EOF
 	},
 	{
diff --git a/udev.8 b/udev.8
index 8f006058..e449ef8d 100644
--- a/udev.8
+++ b/udev.8
@@ -209,7 +209,7 @@ fields support simple printf-like string substitution:
 .TP
 .B %n
 The "kernel number" of the device.
-for example, 'sda3' has a "kernel number" of '3'
+For example, 'sda3' has a "kernel number" of '3'.
 .TP
 .B %k
 The "kernel name" for the device.
@@ -239,7 +239,11 @@ my be selected by specifying the part number as a attribute:
 The content of a sysfs attribute.
 .TP
 .B %%
-The '%' char itself.
+The '%' character itself.
+.P
+The count of charcters to insert may be limited by specifying
+the format length value. For example, '%3s{file}' will only insert
+the first three characters of the sysfs attribute.
 .P
 .RI "A sample " udev.rules " might look like this:"
 .sp
-- 
2.39.5