tee: Replicate Standard Output
Now and then I come across a situation when I need to run a script or a Unix command and would like to not only see the output of it on the screen, but also save this output to some log file. Redirecting the standard output using standard Unix stream redirection isn’t always useful because your output will either be shown to you, or sent to the file – but not both at the same time
tee command
That’s where the tee command becomes really useful. You pipe your output to this command, and let it take care of the rest.
Here’s how you use it:
greys@simplyunix:~$ uname -a | tee /tmp/uname.txt
Linux simplyunix.com 2.6.16.29-xen #1 SMP Sun Sep 30 04:00:13 UTC 2007 x86_64 GNU/Linux
greys@simplyunix:~$ cat /tmp/uname.txt
Linux simplyunix.com 2.6.16.29-xen #1 SMP Sun Sep 30 04:00:13 UTC 2007 x86_64 GNU/Linux
What happens is that tee replicates the standard output to both your session and the specified file.