Variables may not be used as commands

Question

Using fish shell, I'm writing very simple script that checks the command execution

#!/usr/bin/fish
command

if $status
    echo "Oops error"
else
    echo "Worked OK"
    #...
end

And get the error message:

fish: Variables may not be used as commands. Instead, define a function like “function status; 0 $argv; end”. See the help section for the function command by typing “help function”.

The message looks pretty straight forward but no "defining function like..." nor "help function" helps solving the problem.

There is also a 'test' command, that sounds promising. But docs say it is to be used to check files...

How this simple thing should be done with fish shell?

Heh... And why all documentation is SO misleading?..

P.S. Please, don't write about 'and' command.

Answer 1

Fish's test command currently works exactly like POSIX test (i.e. the one you'll find in bash or similar shells). It has a couple of operations, including "-gt", "-eq", "-lt" to check if a number is bigger, equal or less than another number, respectively.

So if you want to use test, you'll do if test $status -eq 0 (a 0 traditionally denotes success). Otherwise, you can check the return value of a command by putting it in the if clause directly like if command (which will be true if the command returns 0) - that's what fish is trying to do here, which is why it complains about a variable being used in place of a command.