首先，你的程序在经由gcc/g++编译的时候，要带上-g选项。比如：g++ test.cpp -g -o test
然后，执行：gdb test
进入gdb界面之后，输入start并回车，则调试开始。（如果被调试的程序需要参数，则在start后面带参数）
以下是常用命令：
help: display help. you can use 'help data', 'help running' for more help
start: start running and suspend
run: start running
n: next
s: step into
c: continue
b: set breakpoint
cl: clear breakpoint
info breakpoints: list all breakpoints
p: print value
disp: keep watch on value
undisp: no longer keep watch on value
where: show stach trace
thread: switch thread
ctrl+c: suspend debug running
list: display source code