zsh: Disable “file exists:” warning with redirection

Question

How can I override the file exists: warning from zsh?

> echo > newfile.txt
> echo > newfile.txt  
zsh: file exists: newfile.txt  

In these cases I prefer my shell to not complain and simply overwrite the file, like bash.

Likewise, how to override the following:

$ ls >> /tmp/testfile.txt                                                                                                                                                   
zsh: no such file or directory: /tmp/testfile.txt

Answer 1

Does your setopt output mention noclobber? If so, that's it, just setopt clobber

The documentation for the option is at http://zsh.sourceforge.net/Doc/Release/Options.html#index-file-clobbering_002c-allowing

Answer 2

You can force the ZSH to clobber on redirect with:

>!

Same as >, except that the file is truncated to zero length if it exists, even if CLOBBER is unset.

or

>>!

Same as >>, except that the file is created if it does not exist, even if CLOBBER is unset.

Answer 3

Others have recommended using >! or >>! but these are not POSIX standard. The POSIx compliant way to overwrite files without prompting is to use >| or >>| and this will work in any shell.

For information see here: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_07_02