Listing Files on the Command Line

Open a command window on any computer and the first thing you see is a prompt waiting for input. On its own, the prompt tells you very little. Every command you type afterward, however, is interpreted against a location on the disk. Before you can use a command-line tool well, you need to know which location it is looking at. This article answers one question: when you type a command and press return, which folder is the computer working in?

The pattern repeats for every command. You type a command, the computer carries it out, any results appear in the window, and a fresh prompt is shown so you can type the next command. Because the window keeps going this way, the location you are working in carries forward from one command to the next. That carried-over location is the subject of the rest of this article.

Consider a command that refers to a file by a short name such as notes.txt. The name alone does not identify one file on the whole machine, because many folders may each hold a file with that name. The command line resolves short names by looking in one designated folder. That folder is the current directory. Whatever short names you type are understood as names inside that folder.

The current directory is therefore an invisible context attached to your session. It does not appear as a separate file or setting that you open. It is simply the answer to the question every command implicitly asks: where should I look for the things you named?

The diagram shows one possible arrangement, which is a generated example and not a fixed layout. The idea it illustrates is the one from the source: the current directory is a single position in the folder tree, and short names are looked up from that position. Folders above it and beside it are not reachable by short name until you move.

Many command prompts make the current directory easier to spot because the directory name is often displayed as part of the prompt itself. Reading the prompt is therefore the quickest way to check where you are before you run anything that depends on location. Get into the habit of glancing at the prompt before every command that works with files.

Once you know where you are, you can see what is there. On Windows the command is dir. On Linux and macOS the command is ls. Each one lists the files in the current directory. Because the listing is taken from the current directory, the list changes whenever the current directory changes.

A fresh command window does not start in an arbitrary system folder. When it first opens, the current directory is set to your home directory, which is your personal folder, the place where your own files are stored. Work through the prediction below before reading on.

This makes a fresh window a predictable starting point. If you want files you saved personally, the new window already points at the folder where they usually live. If you want to work somewhere else, you must move the current directory yourself.

The cd command changes the current directory. You follow cd with the name of the directory you want to move into, then press return. After that, short file names are interpreted inside the new directory, and the prompt usually reflects the new name.

The transition is the whole point of cd. The directory you were standing in is replaced by the one you moved into, and every short name you type afterward is resolved against the new location.

A short name such as notes.txt is resolved against the current directory. This is why the same short name can refer to different files depending on where you are. If you need to refer to a file that is not in the current directory, you can name it in a way that does not depend on your starting position, which is what a full path does. A full path describes the file's location from the top of the disk rather than relative to where you are standing.

The diagram uses a generated arrangement to show the contrast. The short name depends on the current directory and is correct only when that directory holds the file. The full path names the file without reference to your current position, so it does not change when you run cd.