Commands by leovailati

Commands by leovailati (5)

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Stream audio over ssh

This one doesn't need to convert to wav.
This is sample output - yours may be different.
6

ssh [user]@[address] "mpg321 -" < [file].mp3

leovailati · 2010-07-30 00:23:13 2
See udev at work

See how your system works with pendrives/mice/monitors/whatever-you-can-plug-in. Use cases: see on which /dev/... your peripherals are, find out if a specific udev rule is being applied correctly.
This is sample output - yours may be different.
20

udevadm monitor

leovailati · 2010-06-27 00:16:41 14
Use tagged vlans

Great for sysadmins! Don't forget to pass the vlan to your port in a manageable switch. After vconfig, you should use sudo ifconfig eth0.[VID] up Now the interface is up, you can use dhclient or ifconfig again to get an ip address.
This is sample output - yours may be different.
1

sudo vconfig add eth0 [VID]

leovailati · 2010-05-15 21:32:24 2
Change attributes of files so you can edit them

I had problems in Ubuntu while trying to edit /etc/resolv.conf, even with sudo I couldn't make any change. After a 2 minutes search on google I found this command. Hope someone finds it useful. It works like chmod, with + and - to denote which attributes are being added and which are being removed. See other attributes on man pages or on wikipedia http://en.wikipedia.org/wiki/Chattr
This is sample output - yours may be different.
1

sudo chattr -i <file that cannot be modified>

leovailati · 2010-03-25 03:14:34 2
Move itens from subdirectories to current directory

You WILL have problems if the files have the same name. Use cases: consolidate music library and unify photos (especially if your camera separates images by dates). After running the command and verifying if there was no name issues, you can use ls -d */ | sed -e 's/^/\"/g' -e 's/$/\"/g' | xargs rm -r to remove now empty subdirectories.
This is sample output - yours may be different.
-1

ls -d */* | sed -e 's/^/\"/g' -e 's/$/\"/g' | xargs mv -t $(pwd)

leovailati · 2010-03-01 23:43:26 4

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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" }

See all the commits for which searchstring appear in the git diff

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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