Hi All,

I am trying to perform 2 operations on a single Linux command. The operations are :
1) Sending data from source file into a new target file
2) Counting the number of records in the source file.

For example -
Source file - a.txt
target file - b.txt

cat a.txt > b.txt ;
cat a.txt | wc - l

In the above example, I will need to extract data from a.txt twice to perform the 2 operations. However, in my case, the source file is very huge. So for better performance, I am trying to find a way to extract data from source file just once and perform both the operations.

Please help.

Thanks,
Puneeth

The tee command to the rescue! It splits output into two streams, one going to a file, the other to tee’s output.

1 members found this post helpful.

Hi berndbausch,

Thanks for your quick reply. Worked like a charm.

Also (although still two commands) cat is unnecessary for either process.
cat'ing a file and redirecting the output is a very inefficient way to make a copy
wc takes a filename as input. see man wc