tee command is common on Unix like systems and on Windows PowerShell. The tee command writes the input to the file specified and also to the standard output, it was named after the plumbing T-splitter used. Here's a graphical presentation of the tee command: Source: Wikipedia.org Usage The usage can be better demonstrated than explained in theory, follow the few examples below: Code: [pradeep@castellano]$ ls -1 | tee sweetu.lst 1311337262_info.png android.pl android_apps.html apps.dat images info_icon.png jquery.lightbox_me.js llsh.gif main.tpl.html ssearch.pl style.css teaser.gif text.php vikas.php [pradeep@castellano]$ cat sweetu.lst 1311337262_info.png android.pl android_apps.html apps.dat images info_icon.png jquery.lightbox_me.js llsh.gif main.tpl.html ssearch.pl style.css teaser.gif text.php vikas.php The output of the ls command was saved to the file as well as shown on the screen. Example of Practical Use Here, I'll show some practical applications of the tee command for learning and well as implementing if required. Download & untar a tarball on the fly: Code: [pradeep@castellano]$ wget -O- http://search.cpan.org/CPAN/authors/id/S/SP/SPRADEEP/Data-RoundRobinShared-0.11.tar.gz | tee Module.tgz | tar xvz --2013-05-14 00:53:35-- http://search.cpan.org/CPAN/authors/id/S/SP/SPRADEEP/Data-RoundRobinShared-0.11.tar.gz Resolving search.cpan.org... 199.15.176.161 Connecting to search.cpan.org|199.15.176.161|:80... connected. HTTP request sent, awaiting response... 302 Found Location: http://www.cpan.org/authors/id/S/SP/SPRADEEP/Data-RoundRobinShared-0.11.tar.gz [following] --2013-05-14 00:53:35-- http://www.cpan.org/authors/id/S/SP/SPRADEEP/Data-RoundRobinShared-0.11.tar.gz Resolving www.cpan.org... 2620:101:d000:8::140:1, 2a01:608:2:4::2, 207.171.7.177, ... Connecting to www.cpan.org|2620:101:d000:8::140:1|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 2771 (2.7K) [application/x-gzip] Saving to: STDOUT 100%[======================================>] 2,771 --.-K/s in 0s 2013-05-14 00:53:36 (11.8 MB/s) - written to stdout [2771/2771] Data-RoundRobinShared-0.11/ Data-RoundRobinShared-0.11/README Data-RoundRobinShared-0.11/META.yml Data-RoundRobinShared-0.11/Changes Data-RoundRobinShared-0.11/t/ Data-RoundRobinShared-0.11/t/Data-RoundRobinShared.t Data-RoundRobinShared-0.11/MANIFEST Data-RoundRobinShared-0.11/lib/ Data-RoundRobinShared-0.11/lib/Data/ Data-RoundRobinShared-0.11/lib/Data/RoundRobinShared.pm Data-RoundRobinShared-0.11/Makefile.PL [pradeep@castellano]$ ls -l Module.tgz -rw-rw-r-- 1 pradeep pg1555168 2771 May 14 00:53 Module.tgz Copy a file to multiple locations: Code: [pradeep@castellano]$ cat myfile | tee dest1 dest2 > /dev/null 2>&1 Run a command on more than 1 host at the same time: Code: echo "uptime" | tee >(ssh anjali.pradeep.home) >(ssh downloader.pradeep.home) >(ssh nas.pradeep.home)
