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Command Reference: alias

Create an alias for a command

Description

alias defines an alias for global usage

Usage

alias: alias=command parameter parameter

!alias: command

Examples

Because aliases are parsed into an array of parameters, you cannot put the entire alias within quotes. For example:

# bad :(
» alias hw="out Hello, World!"
» hw
exec: "out\\ Hello,\\ World!": executable file not found in $PATH

# good :)
» alias hw=out "Hello, World!"
» hw
Hello, World!

Notice how only the command out "Hello, World!" is quoted in alias the same way you would have done if you'd run that command "naked" in the command line? This is how alias expects it's parameters and where alias on murex differs from alias in POSIX shells.

In some ways this makes alias a little less flexible than it might otherwise be. However the design of this is to keep alias focused on it's core objective. For any more advanced requirements you can use a function instead.

Detail

Allowed characters

Alias names can only include alpha-numeric characters, hyphen and underscore. The following regex is used to validate the alias's parameters: ^([-_a-zA-Z0-9]+)=(.*?)$

Undefining an alias

Like all other definable states in murex, you can delete an alias with the bang prefix:

» alias hw=out "Hello, World!"
» hw
Hello, World!

» !alias hw
» hw
exec: "hw": executable file not found in $PATH

Order of preference

There is an order of precedence for which commands are looked up:

1. test and pipe functions because they alter the behavior of the compiler
2. Aliases - defined via alias. All aliases are global
3. murex functions - defined via function. All functions are global
4. private functions - defined via private. Private's cannot be global and are scoped only to the module or source that defined them. For example, You cannot call a private function from the interactive command line
5. variables (dollar prefixed) - declared via set or let
6. auto-globbing prefix: @g
7. murex builtins
8. external executable files

Synonyms

• alias
• !alias

See Also

• commands/exec: Runs an executable
• commands/export: Define an environmental variable and set it's value
• commands/fexec: Execute a command or function, bypassing the usual order of precedence.
• commands/function: Define a function block
• commands/g: Glob pattern matching for file system objects (eg *.txt)
• commands/global: Define a global variable and set it's value
• commands/let: Evaluate a mathematical function and assign to variable
• commands/method: Define a methods supported data-types
• commands/private: Define a private function block
• commands/set: Define a local variable and set it's value
• commands/source: Import murex code from another file of code block