gdb_showlist

define phead
    set $ptr = $arg1
    plistdata $arg0
end
document phead
Print the first element of a list. E.g., given the declaration
    Glist *datalist;
    g_list_add(datalist, "Hello");
view the list with something like
gdb> phead char datalist
gdb> pnext char
gdb> pnext char
This macro defines $ptr as the current pointed-to list struct,
and $pdata as the data in that list element.
end

define pnext
    set $ptr = $ptr->next
    plistdata $arg0
end
document pnext
You need to call phead first; that will set $ptr.
This macro will step forward in the list, then show the value at
that next element. Give the type of the list data as the only argument.

This macro defines $ptr as the current pointed-to list struct, and
$pdata as the data in that list element.
end

define plistdata
    if $ptr
        set $pdata = $ptr->data
    else
        set $pdata= 0
    end<?dbfo-need height="1in"
?>
    if $pdata
        p ($arg0*)$pdata
    else

        p "NULL"
    end
end
document plistdata
This is intended to be used by phead and pnext, q.v. It sets $pdata and prints its value.
end