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SED Command

 
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# 1  
Old 07-09-2012
SED Command
(sed '' file1 | sort -o file2)


what is (sed '' file1) means?
# 2  
Old 07-09-2012
Code:
cat file1

--
It could all be replaced by:
Code:
sort file1 > file2

# 3  
Old 07-09-2012
Thanks for the response. What exactly single quotes meaning in below command?

sed '' file1
# 4  
Old 07-09-2012
They mean what they always mean in a sh script. It's an empty string. sed never sees those quotes, but it is passed an empty string as its first argument. sed interprets this as an empty list of commands. Given no commands, and without the -n option, sed just prints each line it reads. In other words, as Scrutinizer mentioned, it behaves like cat.

Regards,
Alister
 
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