Shellcompatible

Shellcompatible is a designation used in software development to indicate that a program, script, or library can be executed reliably across a broad range of shell environments without relying on shell-specific extensions. It signals adherence to portable shell practices and predictable behavior in both interactive and automated contexts.

It targets interoperability across common Unix-like shells such as POSIX sh, Bash, Dash, Zsh, and BusyBox sh, and aims to function on major platforms including Linux, macOS, FreeBSD, and Windows environments that provide POSIX-compatible shells. The concept emphasizes using POSIX-compliant syntax, careful handling of quoting and word splitting, and a clean separation of program logic from shell quirks.

Conformance criteria typically include: implementation in a POSIX-compliant manner; avoidance of non-portable extensions; minimal reliance on arrays or process substitution; robust redirection and pipeline usage; explicit error handling and clear exit codes; and a portable shebang such as #!/bin/sh. Developers are encouraged to test shells individually and use portable utility features rather than shell-specific shortcuts.

Adopting shellcompatibility improves portability of CLI tools, installation scripts, and automation workflows, reduces platform-specific maintenance, and eases distribution through package managers and container images. It complements related concepts such as POSIX compliance, cross-shell scripting, and best practices in shell programming.

See also: POSIX, UNIX shell, shell scripting, cross-platform development, command-line interface.