CODEWITHSUNDEEP
zsh
user9327561
user9327561

Reputation:

What's the special meaning of '-' in Zsh?

In bash I have

$ echo -e -
-
$

But I get this in zsh:

$ echo '-'

$ print '-'

$

It seems that this is no substitution like that of ~, etc.

Is this feature documented somewhere? And what is the simplest way to print a single - character if I want to do that?

Upvotes: 0

Views: 189

Answers (2)

Adaephon
Adaephon

Reputation: 18339

Generally a single - has no special meaning in zsh. But this is specific to zsh insofar that echo and print are both built-ins of zsh (echo is also a built-in of bash, but behaves slightly different there - obviously).

A single - denotes that any arguments following it are not to be handled as options. This allows for example to output -E with echo instead enforcing BSD style echo behavior:

% echo -E 'f\x6f\x6fbar'
f\x6f\x6fbar
% echo - -E 'f\x6f\x6fbar'
foobar

For print this is documented in the zshbuiltins manpage. Unfortunatelly it seems to be undocumented for echo.

Following this, the easiest way to output a single - (in zsh) is probably to pass two of it to echo or print:

% echo - -
-
% print - -
-

The first - also disables parsing any further - as options.

Upvotes: 1

Micha Wiedenmann
Micha Wiedenmann

Reputation: 20843

Using printf is more portable and will work more reliable than echo. Try

$ printf '%s\n' -
-

Upvotes: 0

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