what is difference between fork and vfork?

[kapilddit]

when to use fork and vfork? I am using execl in my child. which one I need to use?

[techboy]

vfork() is an obsolete optimization. Before good memory management, fork() made a full copy of the parent's memory, so it was pretty expensive. since in many cases a fork() was followed by exec(), which discards the current memory map and creates a new one, it was a needless expense. Nowadays, fork() doesn't copy the memory; it's simply set as "copy on write", so fork()+exec() is just as efficient as vfork()+exec().