This one is a little bit easier for those of us that aren't always root.

Watch any command (pipes ok, quotes be careful) and keep history in a file. Good for watching and recording any kind of status or error condition, file creations, etc. The choice of "who" as CMD was just to show an obvious usage.

Uses plenty of shell tricks that can be disassembled for simpler stuff. It's deliberately not perfect, but it is generic, and can be customized for your own uses. Had to shorten a little to meet 255 chars.

Better than "watch" how? It keeps a date log of what is going on, and tee'd output is plain-text.

Watch a video while it's downloading. It's additionally saved to the disk for later viewing.

Doesn't work so well if you connect from windows. Linux only sends LF where windows wants CRLF. The alternative command works better with windows, however it uses script and a named pipe.

run 'nc yourip 5000', 'nc yourip 5001' or 'nc yourip 5002' elsewhere will produce an exact same mirror of your shell. This is handy when you want to show someone else some amazing stuff in your shell without giving them control over it.

We sometimes need to change kernel parameters by echoing the file . This needs root privilege and if we do it using sudo like this , it fails

-bash: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: Permission denied

We can achieve this with the tee command by just doing sudo without logging as root user

http://www.zaman4linux.in/2010/09/using-tee-to-echo-to-system-file-with.html

Tee can be used to split a pipe into multiple streams for one or more process to work it. You can add more " >()" for even more fun.

other options:

* replace md5sum with sha1sum for SHA1 checksum

* replace '>' with '| tar zx' for extracting tarball

the tee command does fine with file names, but not so much with file descriptors, such as &2 (stderr). This uses process redirection to tee to the specified descriptor.

In the sample output, it's being used to tee to stderr, which is connected with the terminal, and to wc -l, which is also outputting to the terminal. The result is the output of bash --version followed by the linecount

Streaming HTML5 compatible video (Ogg Theora video with Vorbis sound) to an Icecast server using dvgrab, ffmpeg2theora and oggfwd.

In this example I'm merging stereo sound to mono (-c 1), saving the original dv for later higher quality on-demand video (tee dvstream.dv), saving the theora stream for immediate on-demand video, and publishing the stream in Xiph's stream directory (-p and the name and description).

The URL of the video will be (depending on your server) http://my.icecastserver.com/stream.ogv which will play in newer Firefox, Chrome and Opera web browsers. Cortado (a Java player) can easily be used for IE.

Note also that I'm using port 80, which is not the default port for Icecast, this is to avoid restrictive firewalls.

Also note that ffmpeg2theora 0.25 and will heed the bitrates much better than former versions because of using libtheora 1.1 or newer.

where proc filesystem mounted under /proc

easy way to setup an "internet radio sation", pre-requisite, create an account at an icecast server, in this example, just created beforehand an account at giss.tv.

Change the word password, with the respective real password you created at server.

Make sure to have installed rec, oggnec, oggfwd and tee.

I have a mixer connected at line in, so I can mix music and microphone.

This also will produce a local recorded copy of the session, it will be called "streamdump.ogg"

Write a file you edited in Vim but that you do not have the permissions to write to (unless you use sudo.) Same as #1204 but without the echo to stdout that I find annoying.

I took matthewbauer's cool one-liner and rewrote it as a shell function that returns all the suggestions or outputs "OK" if it doesn't find anything wrong. It should work on ksh, zsh, and bash. Users that don't have tee can leave that part off like this:

If you have some drive imaging to do, you can boot into any liveCD and use a commodity machine. The drives will be written in parallel.

To improve efficiency, specify a larger block size in dd:

To image more drives , insert them as additional arguments to tee:

This function displays the latest comic from xkcd.com. One of the best things about xkcd is the title text when you hover over the comic, so this function also displays that after you close the comic.

To get a random xkcd comic, I also use the following:

This is a cool trick to view the contents of the file on /dev/pts/0 (or whatever terminal you're using), and also send the contents of that file to another program by way of an unnamed pipe. All the while, you've not bothered saving any extra data to disk, like you might be tempted to do with sed or grep to filter output.

Filters out all non-insert SQL operations (we couldn't filter out only lines starting with "INSERT" because inserts can span multiple lines), quotes table names with backticks, saves dump to a file and pipes it straight to mysql.

This transfers only data--it expects your schema is already in place. In Ruby on Rails, you can easily recreate the schema in MySQL with "rake db:schema:load RAILS_ENV=production".

This command will disable the beep sound from the PC speaker.

USAGE: gate listening_port host port

Creates listening socket and connects to remote device at host:port. It uses pipes for connection between two sockets. Traffic which goes through pipes is wrote to stdout. I use it for debug network scripts.