NuttShell (NSH)

The NuttShell is a very complete shell system to be used in NuttX, similar to bash and other similar options. It supports a rich set of included commands, scripting and the ability to run your own applications as “builtin” (part of the same NuttX binary). NSH is implemented as an application where most of the functionality is part of the library called nshlib.

As such, NSH is completely optional and can be disabled so that NuttX directly starts a given task instead of the main nsh application.

Contents

• Overview
  • Console/NSH Front End
  • Command Overview
  • Conditional Command Execution
  • Looping
  • Built-In Variables
  • Current Working Directory
  • Environment Variables
  • NSH Start-Up Script
• Commands
  • Evaluate Expression (test)
  • Add a Routing Table Entry (addroute)
• Configuration Settings
  • Command Dependencies on Configuration Settings
  • Built-In Command Dependencies on Configuration Settings
  • NSH-Specific Configuration Settings
• Customizing the NuttShell
  • The NSH Library and NSH Initialization
  • NSH Commands
• NSH “Built-In” Applications
  • Built-In Applications
  • Synchronous Built-In Applications
• Customizing NSH Initialization
  • NuttShell Start up Scripts
• Shell Login
  • Enabling Shell Logins
  • Verification of Credentials
  • Password Files
  • Creating a Password File for a ROMFS File System