Unix is not an acceptable Unix

Interesting examples, especially in light of the recent debates about Unix shells and PowerShell. In PowerShell, the `ls` command is a simple command that produces output without flags to control output format, ordering or filtering. Like with higher order functional programming, those tasks are delegated to cmdlets like Format-List, Format-Table, Select-Object, Where-Object. Some PowerShell examples: To list the files and directories (children) of a directory: ls To get just the names or the full path: ls |…

Unix permits programs to communicate with one another, and with the user, exclusively through character streams. You can’t write a function that returns a list of files because the shell doesn’t know what a “list” is, doesn’t know what “files” are, and couldn’t tell you the difference between a “function” and a “program” if its life depended on it. Programs don’t “take arguments” and “return values”, they read characters from stdin and print characters to stdout! And this is why…