zsh

Start an interactive zsh shell

$ zsh

$ zsh [script.zsh]

$ zsh -c "[command]"

$ zsh -f

$ zsh -l

$ zsh -n [script.zsh]

zsh [-cefinslvx] [script [args...]]

zsh (Z Shell) is an extended Bourne shell with many improvements, combining features from bash, ksh, and tcsh. It offers powerful completion, theming, and scripting capabilities.
Zsh is highly configurable through ~/.zshrc for interactive settings and ~/.zshenv for all shells. Framework projects like Oh My Zsh and Prezto provide pre-configured themes and plugins.
Key features include advanced tab completion (programmable and context-aware), spelling correction, shared history across sessions, powerful globbing (recursive patterns, qualifiers), and extensive customization options.
Zsh is POSIX-compatible when needed but extends well beyond POSIX with associative arrays, floating-point math, and advanced parameter expansion.

-c string

Execute commands from string

Don't source startup files

Force interactive mode

Login shell

No execute; check syntax only

Read commands from stdin

Verbose; print input as read

Xtrace; print commands as executed

Completion: Context-aware, programmable, menu selection
Globbing: **\*\*/ recursive, (.)** qualifiers for filtering
History: Shared, searchable, substring matching
Prompts: Highly customizable with themes
Aliases: Global aliases, suffix aliases
Arrays: Indexed and associative arrays

Zsh syntax differs from bash in some areas (array indexing starts at 1 by default, different parameter expansion syntax). Scripts may need adjustment.
Heavy customization can slow shell startup. Profile with zprof and lazy-load plugins for faster interactive use.
The default completion system needs initialization with compinit. Most frameworks handle this automatically.

Zsh was created by Paul Falstad at Princeton University in 1990, named after Yale professor Zhong Shao (zsh = Zhong SHell). It has grown into one of the most feature-rich shells available and became the default shell in macOS Catalina (2019).

bash(1), sh(1), fish(1), ksh(1)