Command line (terminal)
- Standard term
The command line is a text interface where you type commands to run programs. The terminal is the window that holds it, and the shell is the program that reads and runs each command.
When you press Enter, the shell splits the line into a program's name and the words after it, then starts that program in the current folder, with your access to your files. Most commands act on files relative to that folder, and deleting from the command line usually skips the trash, with no undo.
Where you’ll meet it
An agent on your computer is clearing out your Downloads folder. It asks permission to run a command that deletes every file ending in .zip, and the request doesn't say which folder the command will run in.
What to do
First ask the agent which folder the command will run in, and have it list the matching files without deleting anything. Approve once that list holds only what you expect to lose. If the list leaves you unsure, ask it to move the files into a new folder instead.
Easy to mix up
An AI agent usually works out what you meant, typo and all, and acts on that. The command line runs exactly what you typed, or fails, with no guess at your meaning.
Check yourself
Your agent runs a command to upload the new version of your website, and it prints “Done” with no errors. What has that shown?
Go deeperThe same command can mean different things in different shells
On macOS the terminal opens zsh by default, most Linux systems use bash, and Windows uses PowerShell or the older Command Prompt. Their rules for quoting, for wildcards such as *.zip, and for chaining commands differ, so a command written for one can fail or do something else in another.
Besides your files, a command can read the saved logins that developer tools keep in your home folder, which is one reason coding agents ask before running one. Many agent tools also offer a sandbox, a restricted mode that limits which folders a command can write to and whether it can reach the internet.