Re: [xml] Problem with basic libxml functions

["William M. Brack" <wbrack mmm com hk>]

Sagar Rastogi said:
> Hi
Hi Sagar

>        I am working on an enhancement to make the panel-run-dialog
> "smart", i.e. it should be able to remember whether the user wanted
> to run
> a command in terminal or not. So next time the user runs the same
> command,
> his preference is remembered. (Bug no. 77300).
>       I am storing the data in an xml file in the foll. format
>
> <?xml version="1.0"?>
> <terminal_preference>
>         <command>
>                 <name> Program name like "galeon" or "nautilus"
> </name>
>                 <terminal> true or false </terminal>
>         </command>
>         <command>
>                 ...
>         </command>
> </terminal_preference>
>
> I am using libxml functions to parse/write to the xml file. I have
> used
> them exactly in the way specified in examples. Foll is a code
> extract:
>
> <snip>
>
>       //cur points to root node at the start.
>       cur = cur->xmlChildrenNode;
>         printf("Reaches here 3.2 \n");  //This gets printed
>         //cur points to command
>         while(cur) {
>                 printf("Reaches here 3.3 \n"); //This gets printed
>                 child_of_cur = cur->xmlChildrenNode;
>
> <snip>

Ah, a most unfortunate spot to "snip"... I can see what you have
done with the variable "child_of_cur", but I have absolutely no way
to tell what you do in the following lines with it or with the
variable "cur".  Certainly the cause of your "crash" is not on these
specific lines of code, but probably somewhere later in the loop.

> The contents of my xml file are:
>
> <?xml version="1.0"?>
> <terminal_preference>
> </terminal_preference>
>
>       As is obvious from the code extract, the control enters the while
> loop
> when it shouldn't. The program crashes at the line:

Hmmm... well, it's not obvious to *me* why it shouldn't enter the
while loop.  Your element <terminal_preference> looks to me like it
has text content which will be a child node, so I would expect it to
enter the loop.

>  child_of_cur = cur->xmlChildrenNode
>       Could somebody please tell me what is the error here?
>
> Regards
> Sagar Rastogi

I heartily recommend to you that you learn to use the gdb debugger,
and step through your code.  That should help you to see where you
are going wrong.

Bill