Cicada – Bash-like Unix shell

Cicada is a Bash-like Unix shell written in Rust. It is designed as a simple daily-use command interpreter, providing familiar shell constructs without attempting to reproduce the full complexity of Bash or compete with feature-heavy shells such as Zsh.

The shell can launch external programs, construct pipelines, redirect input and output, manage foreground and background jobs and perform command substitution. It also supports a lightweight scripting language with conditionals, loops and functions. Interactive facilities include persistent SQLite-based history, syntax highlighting, programmable completion and a highly configurable prompt.

This is free and open source software.

Key Features

• Launch external commands and shell builtins.
• Connect commands using Unix pipelines.
• Input, output and standard-error redirection.
• Command substitution using both backticks and $(command) syntax.
• Run multiple commands separated by semicolons.
• Conditional command execution using && and ||.
• Perform integer and floating-point arithmetic directly at the prompt.
• Supports arithmetic precedence, parentheses and exponentiation.
• Foreground and background job control.
• Suspend jobs and resume them using the bg and fg builtins.
• List active jobs and address them by job or process-group identifier.
• Aliases with alias and unalias management commands.
• Environment-variable assignment, expansion and removal.
• Configurable login-shell startup file.
• Source additional configuration or script files into the current session.
• If, else, for and while scripting constructs.
• User-defined shell functions and positional parameters.
• Filename globbing and brace-range expansion.
• Path, executable and environment-variable completion.
• Built-in completion support for make targets and SSH hosts.
• Custom command completions defined using YAML files.
• Persistent command history stored in an SQLite database.
• Search history by pattern, session or working directory.
• Reverse history search and prefix-based history navigation.
• Optionally exclude commands beginning with a space from history.
• Syntax highlighting recognises commands and command wrappers.
• Customisable prompt with colours, formatting and exit-status indicators.
• Prompt can display the current directory, user, host and Git branch.
• Embed the output of a command in the prompt.
• Builtins for checking commands, inspecting resource limits and managing Python virtual environments.

Website: github.com/mitnk/cicada
Support:
Developer: Hugo Wang
License: MIT License

Cicada is written in Rust. Learn Rust with our recommended free books and free tutorials.

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