ed

ED is a command line text editor that is both minimalistic and powerful. It was one of the earliest text editors developed and included in Unix systems since the 1970s. The name "ed" itself stands for "editor."

ED operates by reading and modifying files directly, without any graphical user interface. It is designed to work in a terminal environment, making it particularly suitable for use over remote connections or in scripting.

Some features of ED include:

1. Line-oriented editing: ED primarily works with text files line by line, allowing users to navigate, search, and modify individual lines.
2. Simple command structure: ED uses a distinct command structure where each command is a single character command preceded by a line address or range. This makes it an efficient tool for scripting.
3. Compactness: ED is very small in size, requiring minimal system resources to run.
4. Regular expressions: It supports regular expressions for pattern matching and searching, providing flexible editing options.
5. Persistent storage: ED typically keeps a copy of the original file, allowing users to undo changes or revert to the initial version.

Despite its minimalistic design, ED can be a versatile tool for editing files in a command line environment, especially when performing quick edits or automating editing tasks through scripting.