A program (binary, or executable) is a file on disk somewhere, in a recognized format. Common formats include ELF on Linux, ...

Using stdin as a file object allows Python to read input, which is piped to it from other commands, and writing to stdout allows it to continue passing the information through the piping system.

I treat my Linux system, with its array of programming tools, as an IDE in itself. IDEs are popular among developers because ...

The bash man page will tell you a little about the eval command, though you would have to scroll down nearly 5,000 lines to find it. There are, after all, no man pages for built-ins.