A breakpoint causes the execution of a program thread to suspend at the location where the breakpoint is set.
断点可以使程序执行的线程悬挂在断点设置的位置。
2
Run from the current statement until a breakpoint (or the end of the program) is reached.
您可以从当前语句开始运行直至到达一个断点（或程序尾部）。
3
To see what's going on in main() we can set a breakpoint at a particular line or on a function in the program code so gdb will interrupt execution when it is reached.