execute_command

The execute_command tool is used to execute CLI (Command Line Interface) commands on the user's system. It allows VJSP to perform system operations, install dependencies, build projects, start servers, and execute other terminal-based tasks to achieve user goals.

Parameters

The tool accepts the following parameters:

• command (required): The CLI command to execute. Must be valid for the user's operating system.
• cwd (optional): The working directory in which to execute the command. If not provided, the current working directory is used.

Functionality

This tool directly executes terminal commands on the user's system, supporting a wide range of operations from file manipulation to running development servers. Commands run in hosted terminal instances with real-time output capture, seamlessly integrated with the IDE's terminal system for optimal performance and security.

Use Cases

• Installing project dependencies (e.g., npm install, pip install, etc.)
• Building or compiling code (e.g., make, npm run build, etc.)
• Starting development servers or running applications
• Initializing new projects (e.g., git init, npm init, etc.)
• Performing advanced file operations beyond the capabilities of other tools
• Running test suites or code linting operations
• Executing specialized commands required for specific technology stacks

Key Features

• Deep integration with IDE shell API for reliable terminal execution
• Intelligent reuse of terminal instances through a registry system, reducing resource consumption
• Real-time capture and streaming of command output
• Support for long-running background commands (such as development servers)
• Allows specifying custom working directories for flexible execution context control
• Maintains terminal history and environment state across command executions
• Intelligently handles complex command chains (pipes, redirections, etc.) appropriate for the user's shell
• Provides detailed command completion status and exit code explanations
• Supports interactive terminal applications requiring user feedback
• Displays terminal in real-time during execution to ensure operation transparency
• Verifies command safety using shell-quote parsing technology
• Proactively blocks potentially dangerous subshell execution patterns (e.g., $(...), backticks)
• Integrates with file access control rules to precisely manage command file operation permissions
• Automatically processes terminal escape sequences to keep output clean and readable

Limitations

• Command access may be restricted by security policies and validation rules
• Commands requiring elevated system privileges may need additional user configuration
• The behavior of certain commands may vary across different operating systems
• Long-running commands may require special resource management handling
• File paths should be properly escaped according to operating system shell rules
• Some advanced terminal features may be limited in remote development scenarios

Working Principle

When the execute_command tool is called, it follows this systematic process:

1. Command Validation and Security Checking:

   • Parses commands using shell-quote to identify individual components
   • Validates commands according to security policies (checking for subshell usage, restricted file access, etc.)
   • Checks file operation permissions for commands according to file access control rules
   • Ensures commands comply with system security requirements and best practices

2. Terminal Management:

   • Obtains or creates terminal instances through the TerminalRegistry
   • Sets up the specified working directory context
   • Configures event listeners for output capture
   • Displays terminal interface for users to monitor execution in real-time

3. Command Execution and Monitoring:

   • Executes commands through the IDE's shell integration API
   • Captures and intelligently processes output containing escape sequences
   • Processes output with a 100ms throttling interval to prevent UI overload
   • Continuously monitors command completion status or error conditions
   • Detects "hot" processes (such as compilers, development servers) for special optimization handling

4. Result Processing:

   • Automatically strips ANSI/IDE escape sequences to keep output clean
   • Parses and interprets exit codes, providing detailed signal information
   • Automatically tracks and updates working directory changes
   • Provides command execution status reports with complete context

Terminal Implementation Details

The tool employs a sophisticated and efficient terminal management system:

1. Intelligent Terminal Reuse:

   • TerminalRegistry prioritizes reusing existing terminal instances
   • Reduces the number of terminal instances, significantly improving performance
   • Preserves terminal state (working directory, history, environment variables) across command executions

2. Multi-layer Security Validation:

   • Uses shell-quote parsing for in-depth command component analysis
   • Proactively blocks dangerous execution patterns like $(...) and backticks
   • Checks command file operation permissions according to file access control rules
   • Implements a prefix allowlist system to validate command pattern security

3. Performance Optimization Strategies:

   • Processes output with 100ms throttling interval, balancing real-time performance and system resource consumption
   • Uses index-based zero-copy buffer management to maximize processing efficiency
   • Implements special performance optimizations for compilation processes and "hot" processes
   • Includes platform-specific adaptation optimizations for environments like Windows PowerShell

4. Robust Error and Signal Handling:

   • Maps exit codes to detailed signal information (such as SIGTERM, SIGKILL, etc.)
   • Detects core dumps to quickly identify critical system failures
   • Automatically tracks and handles working directory changes
   • Gracefully recovers from abnormal scenarios like terminal disconnections

Usage Examples

• When setting up a new project, VJSP runs initialization commands (like npm init -y) and then installs required dependencies
• When building a web application, it executes build commands (like npm run build) to compile and optimize resources
• When deploying code, it runs git commands to commit and push changes to remote repositories
• When troubleshooting, it executes diagnostic commands to collect system and application information
• When starting a development environment, it runs appropriate server commands (like npm start)
• During quality assurance phases, it executes test framework commands to run tests

Usage Syntax

Running a simple command in the current directory:

<execute_command>
<command>npm run dev</command>
</execute_command>

Installing project dependencies:

<execute_command>
<command>npm install express mongodb mongoose dotenv</command>
</execute_command>

Running multiple commands sequentially:

<execute_command>
<command>mkdir -p src/components && touch src/components/App.js</command>
</execute_command>

Executing commands in a specific directory:

<execute_command>
<command>git status</command>
<cwd>./my-project</cwd>
</execute_command>

Building and starting a project:

<execute_command>
<command>npm run build && npm start</command>
</execute_command>