From b1c5e3339deb97f4a30053111b444489a3bc9562 Mon Sep 17 00:00:00 2001
From: "kay.sievers@vrfy.org" <kay.sievers@vrfy.org>
Date: Mon, 15 Dec 2003 22:54:38 -0800
Subject: [PATCH] [PATCH] get part of callout return string

Try this patch if you like, to get special parts of the callout output.
This beast works now:
CALLOUT, BUS="scsi", PROGRAM="/bin/echo -n node link1 link2", ID="node *", NAME="%1c", SYMLINK="%2c %3c"

The callout returned string is separated by spaces and is
addressed by the "len" value of the 'c' format char.
Since we support symlinks, this my be useful for other uses of callout too.

  introduce 'len number' for format chars
  the first use is 'c'-the callout return to select a part of the output string like:
  CALLOUT, BUS="scsi", PROGRAM="/bin/echo -n node link1 link2", ID="node *", NAME="%1c", SYMLINK="%2c %3c"
  (note: first part is requested by len=1, len=0 will return the whole string)
  add a test to udev-test.pl
---
 namedev.c         | 41 ++++++++++++++++++++++++++++++++++++-----
 test/udev-test.pl |  9 +++++++++
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/namedev.c b/namedev.c
index 74a41179..212d6bb6 100644
--- a/namedev.c
+++ b/namedev.c
@@ -200,15 +200,30 @@ static void build_kernel_number(struct sysfs_class_device *class_dev, struct ude
 static void apply_format(struct udevice *udev, unsigned char *string)
 {
 	char name[NAME_SIZE];
+	char temp[NAME_SIZE];
+	char *tail;
 	char *pos;
+	char *pos2;
+	char *pos3;
+	int num;
 
 	while (1) {
+		num = 0;
 		pos = strchr(string, '%');
 
 		if (pos) {
-			strfieldcpy(name, pos+2);
-			*pos = 0x00;
-			switch (pos[1]) {
+			*pos = '\0';
+			tail = pos+1;
+			if (isdigit(tail[0])) {
+				num = (int) strtoul(&pos[1], &tail, 10);
+				if (tail == NULL) {
+					dbg("format parsing error '%s'", pos+1);
+					break;
+				}
+			}
+			strfieldcpy(name, tail+1);
+
+			switch (tail[0]) {
 			case 'b':
 				if (strlen(udev->bus_id) == 0)
 					break;
@@ -241,8 +256,24 @@ static void apply_format(struct udevice *udev, unsigned char *string)
 			case 'c':
 				if (strlen(udev->callout_value) == 0)
 					break;
-				strcat(pos, udev->callout_value);
-				dbg("substitute callout output '%s'", udev->callout_value);
+				if (num) {
+					/* get part of return string */
+					strncpy(temp, udev->callout_value, sizeof(temp));
+					pos2 = temp;
+					while (num) {
+						num--;
+						pos3 = strsep(&pos2, " ");
+						if (pos3 == NULL) {
+							dbg("requested part of callout string not found");
+							break;
+						}
+					}
+					strcat(pos, pos3);
+					dbg("substitute partial callout output '%s'", pos3);
+				} else {
+					strcat(pos, udev->callout_value);
+					dbg("substitute callout output '%s'", udev->callout_value);
+				}
 				break;
 			default:
 				dbg("unknown substitution type '%%%c'", pos[1]);
diff --git a/test/udev-test.pl b/test/udev-test.pl
index 3dfbaa25..1a35e3da 100644
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -150,6 +150,15 @@ EOF
 		expected => "test-0:0:0:0" ,
 		conf     => <<EOF
 CALLOUT, BUS="scsi", PROGRAM="/bin/echo -n test-%b", ID="test-*", NAME="%c"
+EOF
+	},
+	{
+		desc     => "callout program substitution (numbered part of)",
+		subsys   => "block",
+		devpath  => "block/sda/sda3",
+		expected => "link1" ,
+		conf     => <<EOF
+CALLOUT, BUS="scsi", PROGRAM="/bin/echo -n node link1 link2", ID="node *", NAME="%1c", SYMLINK="%2c %3c"
 EOF
 	},
 	{
-- 
2.39.5