How does strace -p work..

["chetan kumar s" <chetan.kumar@xxxxxxxxx>]

Hello,

	I just wanted to know how will the stace attach to a process
when I do 

starce -p <some_pid>


Thanks
Chetan S
___________
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself.  Therefore all
progress depends on the unreasonable man.
                -- George Bernard Shaw