Quoting and Setting $@ to a Variable

Question

I am having trouble resolving how to use double quotes to capture command line arguments in a bash script. I have two files: hello_world and hello world (notice the space in the second filename).

Of course this works:

#!/usr/bin/env bash
ls "$@"

$ ./quoted_args.sh hello_world "hello world"
hello world hello_world

However, none of the following (very similar) scripts work:

Script A:

#!/usr/bin/env bash
FILES="$@"
ls "$FILES"

$ ./quoted_args.sh hello_world "hello world"
ls: hello_world hello world: No such file or director

Script B:

#!/usr/bin/env bash
FILES=$@
ls "$FILES"

$ ./quoted_args.sh hello_world "hello world"
ls: hello_world hello world: No such file or director

Script C:

#!/usr/bin/env bash
FILES="$@"
ls $FILES

$ ./quoted_args.sh hello_world "hello world"
ls: hello: No such file or directory
ls: world: No such file or directory
hello_world

Script D:

#!/usr/bin/env bash
FILES=$@
ls $FILES

$ ./quoted_args.sh hello_world "hello world"
ls: hello: No such file or directory
ls: world: No such file or directory
hello_world

I feel like I have tried every way of doing this. I would appreciate any help or insight!

Answer 1

Store $@ into an array to be able to use it safely in other commands:

# populate files array
files=("$@")

# use array
ls "${files[@]}"

# or directly use "$@"
ls "$@"

Also better to avoid using all uppercase variable names in shell scripts.