just as when typed at shellthe string of arguments passed to os execlp by the forkexec script in example - starts another python program fileas shown in example - example - pp \system\processes\child py import ossys print('hello from child'os getpid()sys argv[ ]here is this code in action on linux it doesn' look much different from the original fork pybut it' really running new program in each forked process more observant readers may notice that the child process id displayed is the same in the parent program and the launched child py programos execlp simply overlays program in the same process[ :\pp \system\processes]python fork-exec py child is hello from child child is hello from child child is hello from child there are other ways to start up programs in python besides the fork/exec combination for examplethe os system and os popen calls and subprocess module which we explored in and allow us to spawn shell commands and the os spawnv call and multiprocessing modulewhich we'll meet later in this allow us to start independent programs and processes more portably in factwe'll see later that multi processing' process spawning model can be used as sort of portable replacement for os fork in some contexts (albeit less efficient oneand used in conjunction with the os execcalls shown here to achieve similar effect in standard windows python we'll see more process fork examples later in this especially in the program exits and process communication sectionsso we'll forego additional examples here we'll also discuss additional process topics in later of this book for instanceforks are revisited in to deal with servers and their zombies--dead processes lurking in system tables after their demise for nowlet' move on to threadsa subject which at least some programmers find to be substantially less frightening parallel system tools