Is it possible in Fish to perform command substitution in a way where I define the command to be treated as a single argument for commands like echo? In Bash it would be equivalent to e.g.:
$ echo "$(cat file.txt)"
lorem
ipsum
The approach suggested by Fish doesn't work for multi-line (or spaced) output:
$ echo (cat file.txt)
lorem ipsum
And if I add quotes, it doesn't perform the command substitution at all:
$ echo "(cat file.txt)"
(cat file.txt)