The principal purposes of using a debugger are so that you can stop your program before it terminates; or so that, if your program runs into trouble, you can investigate and find out why.
Inside GDB, your program may stop for any of several reasons, such
as
a signal,
a breakpoint, or reaching a new line after a GDB
command such as step. You may then examine and change
variables, set new breakpoints or remove old ones, and then continue
execution. Usually, the messages shown by GDB provide ample
explanation of the status of your program--but you can also explicitly
request this information at any time.
info program
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