This command starts screen with 'htop', 'nethogs' and 'iotop' in split-screen. You have to have these three commands (of course) and specify the interface for nethogs - mine is wlan0, I could have acquired the interface from the default route extending the command but this way is simpler. htop is a wonderful top replacement with many interactive commands and configuration options. nethogs is a program which tells which processes are using the most bandwidth. iotop tells which processes are using the most I/O. The command creates a temporary "screenrc" file which it uses for doing the triple-monitoring. You can see several examples of screenrc files here: http://www.softpanorama.org/Utilities/Screen/screenrc_examples.shtml

Get the name of the parent command. This might be helpful, if you need to react on that information. E. g. a script called directly via ssh has got sshd as parent, manually invoked the parent process will probably be bash

If you are doing some tests which require reboots (e. g. startup skripts, kernel module parameters, ...), this is very time intensive, if you have got a hardware with a long pre-boot phase due to hardware checks. At this time, kexec can help, which only restarts the kernel with all related stuff. First the kernel to be started is loaded, then kexec -e jumps up to start it. Is as hard as a reboot -f, but several times faster (e. g. 1 Minute instead of 12 on some servers here). Show Sample Output

Resizes all images in the curent directory to x resolution. It is better than `mogrify -resize *.jpg` because of independence from extension of image (e.g. .jpg and .JPG) (: Show Sample Output

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If you know the benefits of screen, then this might come in handy for you. Instead of ssh'ing into a machine and then running a screen command, this can all be done on one line instead. Just have the person on the machine your ssh'ing into run something like screen -S debug Then you would run ssh -t user@host screen -x debug and be attached to the same screen session.

I wanted all the 'hidden' .flv files from the http link in the command line; wget seemed appropriate, fed with output from lynx, grep the flv files and the normalised via sed (to remove the numeric bullet). Similar to the 'Grab mp3 files' fu. Replace link with your own, grep arg with something more interesting ;) See here for something along the same lines... http://www.commandlinefu.com/commands/view/1006/grab-mp3-files-from-your-favorite-netcasts-mp3blog-or-sites-that-often-have-good-mp3s Hope you find it useful! Improvements welcome, naturally.

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Useful for analyzing disk usage. If you prefer GUI try http://en.wikipedia.org/wiki/Filelight or http://www.marzocca.net/linux/baobab/ Show Sample Output

Useful if you f.i. want to block/allow all connections from a certain provider which uses successive netnames for his ip blocks. In this example I used the german Deutsche Telekom which has DTAG-DIAL followed by a number as netname for the dial in pools. There are - as always ;) - different ways to do this. If you have seq available you can use net=DTAG-DIAL ; for i in `seq 1 30`; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; done or without seq you can use bash brace expansion net=DTAG-DIAL ; for i in {1..30}; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; done or if you like while better than for use something like net=DTAG-DIAL ; i=1 ; while true ; do whois -h whois.ripe.net $net$i | grep '^inetnum:' | sed "s;^.*:;$net$i;" ; test $i = 30 && break ; i=$(expr $i + 1) ; done and so on. Show Sample Output

Only tested on Linux Ubunty Hardy. Works when file names have spaces. The "-maxdepth 2" limits the find search to the current directory and the next one deeper in this example. This was faster on my system because find was searching every directory before the current directory without the -maxdepth option. Almost as fast as locate when used as above. Must use double quotes around pattern to handle spaces in file names. -print0 is used in combination with xargs -0. Those are zeros not "O"s. For xargs, -I is used to replace the following "{}" with the incoming file-list items from find. Echo just prints to the command line what is happening with mv. mv needs "{}" again so it knows what you are moving from. Then end with the move destination. Some other versions may only require one "{}" in the move command and not after the -I, however this is what worked for me on Ubuntu 8.04. Some like to use -type f in the find command to limit the type. Show Sample Output

Strangely enough, there is no option --lines=[negative] with tail, like the head's one, so we have to use sed, which is very short and clear, you see. Strangely more enough, skipping lines at the bottom with sed is not short nor clear. From Sed one liner : # delete the last 10 lines of a file $ sed -e :a -e '$d;N;2,10ba' -e 'P;D' # method 1 $ sed -n -e :a -e '1,10!{P;N;D;};N;ba' # method 2 Show Sample Output

This starts a very basic X session, with just a simple xterm. You can use this xterm to launch your preferred distant session. ssh -X john@otherbox gnome-session Try also startkde or fluxbox or xfce4-session. To switch between your two X servers, use CTRL+ALT+F7 and CTRL+ALT+F8.

When you've got a list of numbers each on its row, the ECHO command puts them on a simple line, separated by space. You can then substitute the spaces with an operator. Finally, pipe it to the BC program. Show Sample Output

I'm pretty sure everyone has curl and sed, but not everyone has lynx. Show Sample Output

apt-get is pretty aggressive when it downloads, potentially hogging the bandwidth of your network. The 25 is in KB, change this to your needs.

Useful when you have some wrong on a server (nfs freeze/ immortal process) Show Sample Output

The command could show you all conecctions if you skip "grep ESTABLISHED" Show Sample Output

Create a bunch of random files with random binary content. Basically dd dumps randomly from your hard disk to files random-file*. Show Sample Output

Query Wikipedia by issuing a DNS query for a TXT record. The TXT record will also include a short URL to the complete corresponding Wikipedia entry.You can also write a little shell script like: $ cat wikisole.sh #!/bin/sh dig +short txt ${1}.wp.dg.cx and run it like ./wikisole.sh unix were your first option ($1) will be used as search term. Show Sample Output

Display the amount of memory used by all the httpd processes. Great in case you are being Slashdoted!

A simple "ls" lists files *and* directories. So we need to "find" the files (type 'f') only. As "find" is recursive by default we must restrict it to the current directory by adding a maximum depth of "1". If you should be using the "zsh" then you can use the dot (.) as a globbing qualifier to denote plain files: zsh> ls *(.) | wc -l for more info see the zsh's manual on expansion and substitution - "man zshexpn". Show Sample Output

works on Linux and Solaris. I think it will work on nearly all *nix-es Show Sample Output

The initial version of this command also outputted extra empty lines, so it went like this: 192.168.166.48 127.0.0.1 This happened on Ubuntu, i haven't tested on anything else. Show Sample Output