an update command

an update command

[zzapper]

Hi
when copying files from a test server to a live server eg

>cp $T/config.php $L

I only want to do the copy if the file ALREADY exists in the destination 
directory 

I guess I can hack a script up to do this but how would you do this? 
-- 
zzapper
http://zzapper.co.uk/ Technical Tips

Re: an update command

[Peter Stephenson]

On Wed, 19 May 2010 09:31:06 +0000 (UTC)
zzapper <david@tvis.co.uk> wrote:
> when copying files from a test server to a live server eg
> 
> >cp $T/config.php $L
> 
> I only want to do the copy if the file ALREADY exists in the
> destination directory 
> 
> I guess I can hack a script up to do this but how would you do this? 

if $L is a directory,

  [[ -e $L/config.php ]] && cp $T/config.php $L

which is easy to turn into a function in various ways.

-- 
Peter Stephenson <pws@csr.com>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


Member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom

Re: an update command

[François Gannaz]

Le 2010-05-19, zzapper <david@tvis.co.uk> a écrit :
> Hi
> when copying files from a test server to a live server eg
> 
> >cp $T/config.php $L
> 
> I only want to do the copy if the file ALREADY exists in the destination 
> directory 
> 
> I guess I can hack a script up to do this but how would you do this? 

That's not related to zsh, but I would use `rsync` with `--existing`.
Rsync is especially useful when files are updated.

Regards
--
François

Re: an update command

[Joke de Buhr]

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You should probably have a look at rsync.

use this command:

   cd $L          // go into the remote directory you want to sync
   print -l **(.) | rsync -av --dry-run --files-from=- $T $L

If rsync lists only the lists you want to copy remove the --dry-run option. 
Create a backup tar archive if you are unsure.



On Wednesday 19 May 2010 11:31:06 zzapper wrote:
> Hi
> when copying files from a test server to a live server eg
> 
> >cp $T/config.php $L
> 
> I only want to do the copy if the file ALREADY exists in the destination
> directory
> 
> I guess I can hack a script up to do this but how would you do this?

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Re: an update command

[zzapper]

zzapper wrote in news:Xns9D7D6AFA2B217zzappergmailcom@80.91.229.10:

> Hi
> when copying files from a test server to a live server eg
> 
>>cp $T/config.php $L
> 
> I only want to do the copy if the file ALREADY exists in the destination 
> directory 

Thanks for responses all good stuff.

Curiously cp has a parameter -update which only copies if src newer than 
dest, unfortunately  (for me) will create a new dest file if none exists



-- 
zzapper
http://zzapper.co.uk/ Technical Tips