Re: Scripting

[Thomas Adam <thomas_adam16@yahoo.com>]

 --- Silvan Villiger <vsilvan@stud.phys.ethz.ch> wrote: 

> I've started to learn scripting in linux. But I have some troubles 
> understandig the redirection of the streams. I tried to test whether a 
> directory already exists using the ls command (didn't find a bether 
> solution) and whenever ls doesn't find such a directory it writes an 

[ -d /some/directory ] && echo "directory exists" >&2 || echo "nope. does
not exist" >&2

Which will echo the reply to stderr.

> Another example I had, was when I tried to compile a latex-file in a 
> script. How can i prevent it from writing compiling-informations to the 
> shell which started the script?

thescript 2> /dev/null

would redirect all errors to the bit-bucket. If you wanted to blank the
entire lot:

thescript > /dev/null 2>&1 

(or, if you don't care for portability, the command above is the same as:

thescript &> /dev/null )

HTH,

-- Thomas Adam

=====
"The Linux Weekend Mechanic" -- http://linuxgazette.net
"TAG Editor"                 -- http://linuxgazette.net

"<shrug> We'll just save up your sins, Thomas, and punish 
you for all of them at once when you get better. The 
experience will probably kill you. :)"

 -- Benjamin A. Okopnik (Linux Gazette Technical Editor)


	
	
		
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