This patch adds a new api call:

int pbx_builtin_serialize_variables(struct ast_channel *chan, char *buf, size_t size);
takes a chan and a char * 'buf' assumed to be 'size' bytes.

The function fills 'buf' with a <CR>('\n') delimited list of name,value pairs in turn delimeted by '='
eg:
SIPCALLID=f30e4e72-f715193f@1.2.3.4
SIPUSERAGENT=Sipura/SPA2000-2.0.6(c)
SIPDOMAIN=1.2.3.4

It returns the acutal number of variables encountered.
If the attempt to fill 'buf' goes beyond 'size' bytes the operation is halted and the incomplete string is returned as is.

To demonstrate a use for this, the "show channel <channame>" command has been retrofitted with the call so it also dumps all of the chan's vars

*CLI> show channel Zap/5-1
 -- General --
           Name: Zap/5-1
           Type: Zap
       UniqueID: 1098480666.17
      Caller ID: 4999
 Caller ID Name: Tony
    DNID Digits: (N/A)
          State: Up (6)
          Rings: 0
   NativeFormat: 68
    WriteFormat: 4
     ReadFormat: 4
1st File Descriptor: 22
      Frames in: 41969
     Frames out: 83240
 Time to Hangup: 0
   Elapsed Time: 0h13m54s
 --   PBX   --
        Context: phone1
      Extension: 4994
       Priority: 2
     Call Group: 2
   Pickup Group: 2
    Application: Dial
           Data: IAX2/ulaw@cube1/00010014994@croip
          Stack: 0
    Blocking in: ast_waitfor_nandfds
Variables:
DIALEDPEERNUMBER=ulaw@cube1/00010014994@croip
DIALEDPEERNAME=IAX2/cube1/3
CALLTYPE=SPEECH
tempvar=tempval


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4051 65c4cc65-6c06-0410-ace0-fbb531ad65f3

cdr.c

@@ -290,6 +290,7 @@ int ast_cdr_init(struct ast_cdr *cdr, struct ast_channel *c)
 			if (!ast_strlen_zero(cdr->channel)) 
 				ast_log(LOG_WARNING, "CDR already initialized on '%s'\n", chan); 
 			strncpy(cdr->channel, c->name, sizeof(cdr->channel) - 1);
+			cdr->chan = c;
 			/* Grab source from ANI or normal Caller*ID */
 			if (c->cid.cid_ani)
 				num = c->cid.cid_ani;

cli.c

@@ -17,6 +17,7 @@
 #include <asterisk/options.h>
 #include <asterisk/cli.h>
 #include <asterisk/module.h>
+#include <asterisk/pbx.h>
 #include <asterisk/channel.h>
 #include <asterisk/channel_pvt.h>
 #include <asterisk/manager.h>
@@ -597,6 +598,7 @@ static int handle_showchan(int fd, int argc, char *argv[])
 {
 	struct ast_channel *c=NULL;
 	struct timeval now;
+	char buf[1024];
 	long elapsed_seconds=0;
 	int hour=0, min=0, sec=0;
 	if (argc != 3)
@@ -649,6 +651,9 @@ static int handle_showchan(int fd, int argc, char *argv[])
 	c->context, c->exten, c->priority, c->callgroup, c->pickupgroup, ( c->appl ? c->appl : "(N/A)" ),
 	( c-> data ? (!ast_strlen_zero(c->data) ? c->data : "(Empty)") : "(None)"),
 	c->stack, (c->blocking ? c->blockproc : "(Not Blocking)"));
+			if(pbx_builtin_serialize_variables(c,buf,sizeof(buf)))
+				ast_cli(fd,"Variables:\n%s\n",buf);
+
 		ast_mutex_unlock(&c->lock);
 		break;
 		}

include/asterisk/cdr.h

@@ -78,6 +78,7 @@ struct ast_cdr {
 	char uniqueid[32];
 	/* User field */
 	char userfield[AST_MAX_USER_FIELD];
+	struct ast_channel *chan;
 	struct ast_cdr *next;
 };
 

include/asterisk/pbx.h

@@ -542,6 +542,7 @@ struct ast_ignorepat *ast_walk_context_ignorepats(struct ast_context *con,
 	struct ast_ignorepat *ip);
 struct ast_sw *ast_walk_context_switches(struct ast_context *con, struct ast_sw *sw);
 
+int pbx_builtin_serialize_variables(struct ast_channel *chan, char *buf, size_t size);
 extern char *pbx_builtin_getvar_helper(struct ast_channel *chan, char *name);
 extern void pbx_builtin_setvar_helper(struct ast_channel *chan, char *name, char *value);
 extern void pbx_builtin_clear_globals(void);

pbx.c

@@ -4903,6 +4903,28 @@ static int pbx_builtin_goto(struct ast_channel *chan, void *data)
 	return 0;
 }
 
+int pbx_builtin_serialize_variables(struct ast_channel *chan, char *buf, size_t size) 
+{
+	struct ast_var_t *variables;
+	struct varshead *headp;
+	int total = 0;
+
+	memset(buf,0,size);
+	if (chan) {
+		headp=&chan->varshead;
+		AST_LIST_TRAVERSE(headp,variables,entries) {
+			snprintf(buf + strlen(buf), size - strlen(buf), "%s=%s\n", ast_var_name(variables), ast_var_value(variables));
+			if(strlen(buf) >= size) {
+				ast_log(LOG_ERROR,"Data Buffer Size Exceeded!\n");
+				break;
+			}
+			total++;
+		}
+	}
+	
+	return total;
+}
+
 char *pbx_builtin_getvar_helper(struct ast_channel *chan, char *name) 
 {
 	struct ast_var_t *variables;