command

Run a command ignoring shell functions

$ command [ls]

$ command -v [git] && echo "git is installed"

$ command -v [python3]

$ command -V [cd]

$ ls() { command ls --color=auto "$@"; }

command [-pVv] command [arguments]

command is a shell builtin that executes a command, bypassing shell functions with the same name. This is essential when writing wrapper functions that need to call the original command they're wrapping.
With -v, it prints how the command would be resolved: the path for external commands, the definition for aliases, or indication for builtins and functions. This is the POSIX-portable way to check if a command exists (preferred over which).
The -V option provides verbose output describing what type of command it is (builtin, function, alias, or external) and where it's defined.

-v

Print the pathname or alias that would be used (like which).

Verbose description of command type.

Use default PATH to find command, ignoring custom PATH.

Wrapper function calling original:

$ ls() {
    command ls --color=auto "$@"
}

$ if command -v docker > /dev/null 2>&1; then
    echo "Docker is installed"
fi

command is a shell builtin, not an external program. Behavior may vary slightly between shells (bash, zsh, dash). The -v option returns success (0) if the command exists, making it ideal for conditional checks. Unlike which, it handles builtins and functions correctly.

The command builtin was specified in POSIX.2 (1992) to provide a standard way to bypass function lookup and check command availability. It was designed to replace non-portable utilities like which for determining command paths. The builtin is available in all POSIX-compliant shells including bash, dash, zsh, and ksh.

type(1), which(1), builtin(1), hash(1)