Operating Systems 2014F Lecture 3

Process API

Highly orthogonal - not only one way of doing things. Concept of Symbolic links, vs. hard links in Unix. In windows, there are about 5 different versions of links, and some of them work on some versions of windows. It's a complete mess.

They first introduced 1 api, that turned out to be bad w/ limited functionality. Evolution of windows - you look at their API and you get a mess.

ioctl - system call in unix / linux systems -an abomination - it doesnt' have well defined semantics - io control you give it the number of a device, and some arguments, and it varies from device to device as to what it does. In unix that is the exception. Most of the base stuff is clean. The people who worked at bell labs were smart, they created a system that they wanted to use for themselves.

In Unix, you don't call 1 call - you have 2 calls.

fork()

The classic structure of how to use fork:

if (fork()) {

} else {

}

execve(, , )

specific use cases for using both individually, without having to call both of them.