Commands by longqi (1)

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Stream audio over ssh
This will allow you to convert an audio file to wav format, and send it via ssh to a player on the other computer, which will open and play it there. Of course, substitute your information for the sound file and remote address You do not have to use paplay on the remote end, as it is a PulseAudio thing. If the remote end uses ALSA, you should use aplay instead. If it uses OSS, you should berate them about having a lousy sound system. Also, you're not limited to transmitting encoded as wav either, it's just that AFAIK, most systems don't come with mp3 codecs, but will play wav files fine. If you know SoX is installed on the remote end and has mp3 codecs, you can use the following instead: $ cat Klaxon.mp3 |ssh thelab@company.com play -t mp3 - this will transmit as mp3. Again, use your specific information. if you're not playing mp3s, use another type with the -t option

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

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Compare / diff two images
Outputs the number of different pixels. 2 params to increase tolerance: * thumbnails size * fuzz, the color distance tolerance See http://en.positon.org/post/Compare-/-diff-between-two-images for more details.

Time Synchronisation with NTP

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Find common groups between two users

mp3 streaming

FizzBuzz in Perl
Just another FizzBuzz in Perl.

Reboot machine when everything is hanging
If the machine is hanging and the only help would be the power button, this key-combination will help to reboot your machine (more or less) gracefully. R - gives back control of the keyboard S - issues a sync E - sends all processes but init the term singal I - sends all processes but init the kill signal U - mounts all filesystem ro to prevent a fsck at reboot B - reboots the system Save your file before trying this out, this will reboot your machine without warning! http://en.wikipedia.org/wiki/Magic_SysRq_key

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