Shellsthat

Shellsthat is a term used in computing to describe the family of interactive command-line environments, or shells, that interpret user input and execute programs. While not widely recognized as a formal term, shellsthat is sometimes used in discussions to refer to the broad class of shells and their capabilities, including scripting constructs, interactive features, and portability concerns.

Prominent examples include Bourne-compatible shells such as sh, Bash, and Dash; C-like shells such as csh and tcsh; and advanced interactive shells such as Zsh and Fish. These shells differ in syntax, features, and extensions, but most provide core capabilities: a command prompt, history, job control, redirection and pipelines, and the ability to write scripts.

Design goals: POSIX compliance (POSIX sh) for portability; interactive enhancements like spell-correcting, auto-suggestions, programmable completion, globbing, and themes. Many shells support plugins and frameworks (e.g., Oh My Zsh for Zsh, Fisher for Fish) that extend functionality, theming, and autocompletion.

Usage and compatibility: scripts written for one shell may fail on another if they rely on non-POSIX features. POSIX sh provides a baseline for portability, while shells like Bash or Zsh offer extended syntax. Users choose shells based on performance, syntax preferences, and ecosystem.

Evolution: Since the 1980s, shells have evolved from simple command interpreters to rich environments capable of complex scripting and interactive features. The term shellsthat thus captures the diversity of shell environments rather than a single standard.