Debugging infinite loops:

The most ubiquitous problem is a program going in an infinite loop. For this do the following steps:

1. Run dbx program_name.
2. Execute the program by run [argument list]. At this point the program is in infinite loop.
3. Press ctrl-c and break the loop.
4. See the trace by the command t. The very first function listed in the trace contains the infinite loop.
5. Single step inside the function.