Alias built-in

The alias built-in defines aliases or prints alias definitions.

Synopsis

alias [name[=value]…]

Description

The alias built-in defines aliases or prints existing alias definitions, depending on the operands. With no operands, it prints all alias definitions in a quoted assignment form suitable for reuse as input to alias.

Options

None.

Non-POSIX options may be added in the future.

Operands

Each operand must be of the form name=value or name. The first form defines an alias named name that expands to value. The second form prints the definition of the alias named name.

Errors

It is an error if an operand without = refers to an alias that does not exist.

The portable option causes additional errors; see Compatibility.

Exit status

Zero unless an error occurs.

Examples

See Aliases.

Compatibility

The alias built-in is specified by POSIX.1-2024.

POSIX only requires alias names consisting of ASCII letters, digits, !, %, ,, -, @, and _ to be supported. By default, yash-rs allows other characters as well. (Since 3.3.1) When the portable option is set, it is an error to define an alias whose name contains a character other than the above. The alias is not defined in that case.

Some shells have predefined aliases that are printed even if you have not defined any explicitly.