mjhjmtu

In writing the question:

How to touch and cat file named -

I was trying to generalise to a case where a file named - was stored in a variable.

In zsh, I tried setting a variable to contain a single hyphen:

% var=-
% echo $var

% var='-'
% echo $var

% var=-
% echo $var

%

Why don't these work?

Why is zsh different to bash in this regard?

How do I set $var to -?

Again, as often, it's not the value actually in the variable, but how the variable is. The echo in this case. Zsh's echo takes the single dash as an end of options indicator, so it's removed. Online manual:

Note that for standards compliance a double dash does not terminate option processing; instead, it is printed directly. However, a single dash does terminate option processing, so the first dash, possibly following options, is not printed, but everything following it is printed as an argument. The single dash behaviour is different from other shells. For a more portable way of printing text, see printf, and for a more controllable way of printing text within zsh, see print.

So we have:

zsh% echo -

zsh% echo - -n
-n
zsh% var=-
zsh% printf "%sn" "$var"
-

See also:

• Why is printf better than echo?