Hi. I have open a file in Emacs called Insertion_sort_in_C.c.
I have found some commands in the web such as C-x 2 (split Emacs screen).
In Emacs under the 'Tools' option I have selected the 'Shell command' feature.
Now at the bottom of emacs window a command line prompt is awaiting for a command.
In this prompt I typed 'C-x 2' but the reply was '/bin/bash: C-x: command not found'
I typed as well the 'M-x gdb' command to initiate the debugger but '/bin/bash: M-x: command not found' came up
Then I run the debugger by the 'Tools' tab and the (gdb) prompt came  up. I typed 'break 11' to enter a 
breakpoint in line 11 of Insertion_sort_in_C.c but warning: 'No symbol table is loaded.  Use the "file" command' came up.

I also thought that when the debugger is running I could left-click in the fringe so that a red disk
appears (a breakpoint). But nothing happens.

Is there anything wrong with Emacs/gdb?

Alexandros