How to debug with gdb in five easy steps:

Step One: Write program

Step Two: Compile program, including –g command.

g++ -W –Wall –g testprogram.cc –o testprogram

Step Three: Start debugger.

gdb testprogram

Step Four: Run broken program. Find errors. Set breakpoints, rerun program to trace variables in problem areas. Rinse. Repeat.

Step Five: Promise yourself you will never rely on “When in doubt, cout!” to debug your programs again!

The details:

run	Executes your program
break	Set a breakpoint for the debugger in the code. break 7 // sets a break at line 7 break sort // breaks at beginning of function sort( )
next	Executes next line of code, then stops
step	Steps into a function and executes first line. Otherwise, ‘next’ would execute entire function and return without stopping.
print	At any point while the program is still running, you can type print and a variable name, and see the value of the variable. print a print myList[24]
continue	Will continue execution of program until another breakpoint, crash, or the end is reached, whichever comes first.
where	Spits out a backtrace through the stack. Will show you which functions you have initiated but not completed. If you don’t understand, play with it a little and the meaning will become clear.
set args	What you must type before ‘run’ if you need to pass arguments into your program. set args circuitFile.txt
disable	Unsets a breakpoint. disable 7 // unset break previously set at line 7.
watch	Similar to break, but you assign it to a variable, and the program will pause execution whenever that variable changes value. watch andGateFive.outputA
quit	How you get out of the debugger.
help	If you really want to know more.