A text-based user interface to the computer. The command line is a blank line and cursor on the screen, allowing the user to type in instructions for immediate execution. All major operating systems (Windows, Mac, Unix, Linux, etc.) support command lines that programmers and power users can employ to perform file management operations directly and often more efficiently than by using a graphical user interface (GUI). After typing a command, it is executed by pressing the Enter key.
Windows Examples
There are numerous Windows commands in this encyclopedia, and two examples follow. To do these operations in Windows Explorer or a Windows-based Pkzip utility would take numerous mouse clicks. See
Windows commands.
Command Operation Performed
copy *.html d:\abc Copy HTML files to
ABC folder in D drive
pkzip xyz *.jpg Compress all JPEG
files into the Zip
archive XYZ.ZIP.
Interactive or Sequential
Commands can be executed one at a time by typing the command and pressing Enter. They can also be executed as a group, in which case the commands are typed into a "batch" or "script" file. The file name is typed on the command line, and pressing Enter causes each command to be executed in order. See
batch file abc's,
cmd abc's,
command processor and
PowerShell.
Windows Command Line
After the command prompt was launched, the command cd /stage switches focus to the STAGE folder. The dir *.cmd lists all the Windows batch files, and prepnew executes the commands in the prepNEW.cmd file.
Mac/Unix/Linux Command Line
This example from macOS, which is a Unix-based operating system, shows two commands issued after the command line ("terminal window") was launched. The cd desktop switches focus to the desktop, and ls X* lists all files that begin with upper case "X."