Running an alias in a bash script gives me `<arguments>: command not found`-CodePudding

I have a script with an alias _test. It works fine, but before printing the output, it does <arguments>: command not found. For example, _test -h gives line 49: -h: command not found

This is a minimal example:

alias _test='
echo Hi
'
shopt -s expand_aliases

_test -h

EDIT: For those asking about using functions, I did in fact, used to have a function instead -- but it started to cause recursion problems. I just wanted something similar to a macro -- something that acts as if the text was inserted into the script.

EDIT 2: I just realized why I kept having recursion with my function/alias. I fixed it, and I switched back to a function, but this question may help someone else.

CodePudding user response：

Remove the newlines. As written, _test -h expands to this, with a blank line above and below the echo:


echo Hi
-h

Make it a one-line alias:

alias _test='echo Hi'

In general, though, avoid aliases. They're really intended for convenience in interactive shells. In a script—or heck, even in interactive shells—it's better to use functions instead. For example:

_test() {
    echo Hi "$@"
}

For those asking about using functions, I did in fact, used to have a function instead -- but it started to cause recursion problems. I just wanted something similar to a macro -- something that acts as if the text was inserted into the script.

Were you trying to wrap an existing command, like this?

alias ls='ls --color=auto -F'

If so you can use command to prevent a function calling itself recursively. The equivalent function would be:

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

command ls calls the ls command rather than the ls function we've just defined so we don't get stuck in an infinite recursive loop.

CodePudding user response：

Thanks to Kugelman's answer, I was able to solve it with

alias _test='
echo Hi
true'
shopt -s expand_aliases

_test -h