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Wsh-Shell

Wsh-Shell is a lightweight, portable, and fully static shell interpreter written in C, designed for embedded systems. It requires no dynamic memory allocation and is built to run in constrained environments like microcontrollers, either bare-metal or under RTOS (e.g., FreeRTOS).

🚀 Features

  • Cross-platform, Highly Portable — only one header file to include
  • Single State Structure — all shell state contained in a single WshShell_t instance
  • Static Memory Only — no malloc, no heap; all buffers are statically allocated
  • Modular Design — ability to disable submodules for memory footprint optimization
  • Command-line Editing — supports cursor movement, character deletion, and insert mode
  • Command Parsing & Options:
    • Supports short (-h) and long (--help) flags
    • Supports int, float, string and other option types
    • Supports double-quoted strings
  • Group-based Access Control — each command belongs to one or more logical groups; users are granted access only if their group set intersects with the command’s group set
  • Fine-grained Option Access Rights — every command option (-f, --reset, etc.) has an associated access flag (read, write, execute, admin); the shell enforces these permissions at runtime and reports mismatches
  • Escape Sequence Handling:
    • Parses VT100/ANSI sequences
    • Supports arrow keys, delete, backspace, sound alerts, etc.
    • Handles key combinations (Ctrl+C, Ctrl+D, etc.)
  • Command History:
    • Implemented as a circular buffer
    • Efficient with hash-based integrity checks
    • Navigable with arrow keys (↑, ↓)
  • Autocomplete:
    • Tab / double-Tab completion for commands and flags
  • Multi-User Support — groups, access rights, and more
  • Customizable PS1 Prompt — user-defined templates for prompt appearance
  • Await Prompt — await for a specific key press
  • Different New Line Support - handle different terminals setup (\r, \n or \r\n)
  • Passwords Stored Salted & Hashed — passwords are supplied and verified through a user-provided callback and always stored in a salted, hashed form; by default the module uses a lightweight Jenkins (non-cryptographic) hash, and no plaintext passwords are written to flash unless the integrator explicitly chooses to do so
  • Command Option Validation — during command registration, the shell automatically checks for duplicate short or long option flags within the same command and triggers an ASSERT if duplicates are detected

👾 Demo

Demo

💾 Memory footprint

  • Build options: cortex-m7, -O1 optimization
  • sizeof(WshShell_t) = 404 bytes
Config FLASH, KB Comment
All features disabled 4.06836
+WSH_SHELL_PRINT_SYS/INFO/WARN/ERR 4.58008 Not recommended to disable shell messages
+WSH_SHELL_INTERACTIVE_MODE 4.68164
+WSH_SHELL_HISTORY 5.63867
+WSH_SHELL_AUTOCOMPLETE 6.19727
+WSH_SHELL_PS1_CUSTOM 6.66992
+WSH_SHELL_PROMPT_WAIT 6.78516
+WSH_SHELL_DEF_COMMAND 8.44922
+WSH_SHELL_PRINT_OPT_HELP 8.44922 Could be usefull on huge amount of external commands
+WSH_SHELL_CMD_PRINT_OPT_OVERVIEW 8.69922 Could be usefull on huge amount of external commands

⌨️ Code counting

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===============================================================================
 Language            Files        Lines         Code     Comments       Blanks
===============================================================================
 C                      13         2102         1610           52          440
 C Header               17         2093          758         1095          240
===============================================================================
 Total                  30         4195         2368         1147          680
===============================================================================

👨‍💻 Authors

⚖️ License

This project is licensed under the MIT License.

You are free to use, modify, and distribute this software in both commercial and non-commercial projects, provided that the original copyright notice and this permission notice are included.

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