[gPXE-devel] [PATCH] [hci] Modify 'set' command to allow space separated values

[Aaron Brooks]

At our site we want to be able to store a series of values from a
single DHCP option (in our case, kernel arguments) in this manner:

    set kargs ${net0/224:string}

I'm including our patch which allows multiple value arguments to the
'set' command. This change does not break or affect existing 'set'
usage but will now make it legal to store space concatenated values.

Let me know if you would like me to change any aspects of the implementation.

I've fully tested the functionality including both error paths.

Sincerely,

Aaron

-------------
From: Aaron Brooks <aaron at brooks1.net>
Date: Sun, 12 Sep 2010 22:53:45 -0400
Subject: [PATCH] [hci] Modify 'set' command to allow space separated values

The 'set' command previously assigned an identifier with the single
value of the following positional argument. The following would assign
the value of "bar" to the identifier of "foo"

    set foo bar
    show foo
    foo = bar

Providing additional positional arguments would lead to an error.

The modification allows multiple positional arguments (either direct
or via identifier expansion) to be concatenated with spaces and
assigned as a single value to the declared identifier "foo":

    set foo bar baz quux
    show foo
    foo = bar baz quux

This functionallity was added to allow for multiple, space separated
values (such as kernel arguments, passed via DHCP) to be assigned to an
identifier.

Signed-off-by: Aaron Brooks <aaron at brooks1.net>
---
 src/hci/commands/nvo_cmd.c |   41 +++++++++++++++++++++++++++++++++++++----
 1 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/hci/commands/nvo_cmd.c b/src/hci/commands/nvo_cmd.c
index 5eb2f06..ac18ee3 100644
--- a/src/hci/commands/nvo_cmd.c
+++ b/src/hci/commands/nvo_cmd.c
@@ -30,19 +30,52 @@ static int show_exec ( int argc, char **argv ) {
 }

 static int set_exec ( int argc, char **argv ) {
+	char *buf;
+	int len = 0;
+	int ofs = 0;
+	int i;
 	int rc;

-	if ( argc != 3 ) {
-		printf ( "Syntax: %s <identifier> <value>\n", argv[0] );
+	if ( argc < 3 ) {
+		printf ( "Syntax: %s <identifier> <value>...\n", argv[0] );
 		return 1;
 	}

-	if ( ( rc = storef_named_setting ( argv[1], argv[2] ) ) != 0 ) {
+	/* Compute length of buffer */
+	for ( i = 2; i < argc; i++ ) {
+		len += strlen ( argv[i] );
+		/* For joining space or trailing null */
+		len += 1;
+	}
+
+	buf = malloc ( len );
+	if ( ! buf ) {
+		const char *emsg = strerror ( errno );
+		printf ( "Could not allocate memory to set \"%s\"=\"", argv[1] );
+		for ( i = 2; i < (argc - 1); i++ ) {
+			printf ( "%s ", argv[i] );
+		}
+		printf ( "%s\": %s\n", argv[i], emsg );
+		return 1;
+	}
+
+	/* Join arguments into buffer with spaces */
+	for ( i = 2; i < argc; i++ ) {
+		strcpy ( buf + ofs, argv[i] );
+		ofs += strlen ( argv[i] );
+		buf[ofs] = ' ';
+		ofs += 1;
+	}
+	buf[ofs - 1] = '\0';
+
+	if ( ( rc = storef_named_setting ( argv[1], buf ) ) != 0 ) {
 		printf ( "Could not set \"%s\"=\"%s\": %s\n",
-			 argv[1], argv[2], strerror ( rc ) );
+			 argv[1], buf, strerror ( rc ) );
+		free ( buf );
 		return 1;
 	}

+	free ( buf );
 	return 0;
 }

-- 
1.7.0.4