HP gnu source-level debugger 5992-4701 Set the debugger response to a program call, Unimpeded

set follow-fork-mode mode	Set the debugger response to a program call of
	fork or vfork. A call to fork or vfork creates
	a new process. The mode can be:
	parent	The original process is debugged after
		a fork. The child process runs
		unimpeded. This is the default.
	child	The new process is debugged after a
		fork. The parent process runs
		unimpeded.
show follow-fork-mode	Display the current debugger response to a fork
	or vfork call.

If you ask to debug a child process and a vfork is followed by an exec, GDB executes the new target up to the first breakpoint in the new target. If you have a breakpoint set on main in your original program, the breakpoint will also be set on the child process's main.

When a child process is spawned by vfork, you cannot debug the child or parent until an exec call completes.

If you issue a run command to GDB after an exec call executes, the new target restarts. To restart the parent process, use the file command with the parent executable name as its argument.

You can use the catch command to make GDB stop whenever a fork, vfork, or exec call is made. See “Setting catchpoints” (page 56).

50 Running Programs Under GDB