bash command incompatibility

bash command incompatibility

[Petre Bandac]

[petre@xxl]$ cat /dev/null > fetchmail.log                              
     ~
zsh: file exists: fetchmail.log
[petre@xxl]$                                                            


when using bash, this was the command to empty the log files. why
doesn't it work in zsh ?

thanks,

petre

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Re: bash command incompatibility

[Peter Stephenson]

Petre Bandac wrote:
> [petre@xxl]$ cat /dev/null > fetchmail.log
>      ~
> zsh: file exists: fetchmail.log
> [petre@xxl]$
>
>
> when using bash, this was the command to empty the log files. why
> doesn't it work in zsh ?

Somewhere in one of the startup scripts someone has put `setopt
noclobber'.  You need to turn it off:

unsetopt noclobber

Putting this in ~/.zshrc should be late enough to cancel it if it's in
one of the system startup scripts.

The option actually exists in bash, too, but clearly wasn't turned on.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: bash command incompatibility

[Wayne Davison]

On Wed, Jul 28, 2004 at 11:07:34AM +0300, Petre Bandac wrote:
> [petre@xxl]$ cat /dev/null > fetchmail.log                              

As an alternative to turning off the no_clobber option (as Peter
suggested), you can just tell zsh that you know that the file already
exists by using a '|' after the '>', like this:

    cat /dev/null >|fetchmail.log

If you enable the option hist_allow_clobber, then any time you get a
"file exists" error, you can just recall the command from the history
and press Enter because the '|' will have been added for you.

Finally, you can avoid the problem all together by using cp:

    cp /dev/null fetchmail.log

That works in any shell and is easier to type.

..wayne..

Re: bash command incompatibility

[Dan Nelson]

In the last episode (Jul 28), Wayne Davison said:
> On Wed, Jul 28, 2004 at 11:07:34AM +0300, Petre Bandac wrote:
> > [petre@xxl]$ cat /dev/null > fetchmail.log                              
> 
> As an alternative to turning off the no_clobber option (as Peter
> suggested), you can just tell zsh that you know that the file already
> exists by using a '|' after the '>', like this:
> 
>     cat /dev/null >|fetchmail.log

I prefer the ! syntax, since | means "pipe" to me, and vi also uses ! as a
"force" flag.

-- 
	Dan Nelson
	dnelson@allantgroup.com