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

Shell scripting is an often forgotten programming environment, relegated to simple automation tasks and little else. In fact, it’s possible to achieve much more complex tasks in the shell.

Simply put, a Shell Script is a program that is run by a UNIX/Linux shell. It is a file that contains a series of commands which are executed sequentially as if they were entered on the command line ...

After the shell script is written, it is made usable by changing its file status to "executable" with the change mode command (see chmod). Shell scripts are the Unix/Linux counterpart to Windows ...

Shell scripts are not compiled — at least, not typically — so the shell only reads what it needs to do the work. That means if your script is careful to exit, you can add as much “garbage ...

In the final script, of course, you won't echo the entered password, as that's not so good from a privacy and security perspective. To test for length, it's easy to use wc -c, but there's a special ...