How to safely echo all arguments of a script?

Question

I am writing a bash script that must echo all of its arguments, which is surprisingly difficult to do.

The naive implementation looks like this:

#!/bin/bash
echo "$@"

However, that fails with input such as:

> ./script.sh -n -e -v -e -r
-v -e -r> 

How can I make this more robust, such that the above results in:

> ./script.sh -n -e -v -e -r
-n -e -v -e -r
> 

Answer 1

echo command's behavior may be different between systems. The safest way is to use printf:

printf '%s\n' "$*"

According to posix:

It is not possible to use echo portably across all POSIX systems unless both -n (as the first argument) and escape sequences are omitted.

The printf utility can be used portably to emulate any of the traditional behaviors of the echo utility ...