Overwrite


 
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# 8  
OK. Now it is clear. You want to overwrite an existing file with data from another file. Wheeew! I feel better now Smilie

Strange, I never get a 'file exists' error in KSH and my problem is that I sometimes overwrite files I shouldn't have Smilie

Example (as root) in KSH:

Code:
# echo hello > a
# echo world > b
# cat b > a
# cat a
world

Interesting. Perhaps you are getting the error because you don't have permissions to write over the file?
# 9  
what is the noclobber variable? what does it do?

BTW, thx PXT, it worked!

Neo: indeed I have permissions to write over the file as I can delete, append etc...and now with >| i can overwrite : )

thanks everyone!
# 10  
Quote:
what is the noclobber variable? what does it do?

If you turn on the noclobber option with "set noclobber" then redirecting to an existing file using the > should produce an error. In csh/tcsh this can be overridden on a case-by-case basis with >!, in bash/ksh it is >|

In csh/tcsh you also have the &gt;&gt;! syntax. If noclobber is set, and you use &gt;&gt; to append to a file, you will get an error if the file does <I>not exist</I> (can't append to a non-existant file). If you use &gt;&gt;! you will override this behaviour, and create the file if it does not already exist. I dont believe that bash or ksh have this feature (file is always created if it does not exist).

noclobber is a handy option if you tend to frequently overwrite files that you intended to keep. See the relevant manual page for your shell to learn more about this and other options.



[Edited by PxT on 03-27-2001 at 12:34 AM]
 

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