Simple VT-compatible Linux Terminal Emulator

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中文

Introduction

go-ansiterm is a Linux terminal emulator similar to pyte, specifically designed for the Go language. While retaining the powerful features of pyte, it further adapts to the Go ecosystem.

Use Cases

In scenarios involving jump servers and other situations that require strict management of user terminal command execution, it's necessary to filter commands before they are executed by the user. In the development stack based on Golang, we haven't found any related open-source libraries. Additionally, some open-source jump server projects do not support command extraction. Therefore, this tool is mainly developed based on practical needs, to solve the problem of extracting commands executed by terminal users.

Core Features

• Command Extraction: The core functionality lies in extracting effective information from terminal outputs and echoes, mainly focusing on user command extraction. This feature is extremely useful in jump servers for the convenient extraction and effective filtering of executed commands.

• Screen Simulation: Includes a screen simulator capable of processing character streams on the screen, supporting operations like cursor movement and text scrolling.

• ANSI Escape Sequences: Handling various ANSI escape sequences for enhanced terminal interactions.

How to Require

    go get github.com/veops/go-ansiterm

Usage Guide

# First, create a screen object
screen := NewScreen(80, 24)

# Create a stream object
stream := InitByteStream(screen, false)

# Connect the stream object to the screen
stream.Attach(screen)
defer stream.Close()

# Feed input into the stream object
stream.Feed(input)

# output
output := screen.Display()

Stream lifecycle and command checks

Call Close() when a session ends, including when it disconnects during an escape sequence. Close() waits for the parser worker to exit and is idempotent. Feed, Attach, InitializeParser and Close are serialized. Direct screen access must be serialized by the caller with these operations.

The screen represents terminal output, including edits echoed by the remote shell. This library does not execute commands or enforce authorization. A bastion must check input before forwarding the submission to the target, use the echoed screen to reconcile command edits, and maintain its own permissions, command policy and audit trail. Screen output alone cannot safely authorize multiline paste, shell scripts or commands that have already been forwarded.