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Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously

Kill a broken ssh connection
This is useful for example if you are on ssh in a server and the server goes down without letting you out. This is part of a larget sets of escape sequences provided by ssh. You can find them with ~? Here's the list: ~. - terminate connection (and any multiplexed sessions) ~B - send a BREAK to the remote system ~C - open a command line ~R - request rekey ~V/v - decrease/increase verbosity (LogLevel) ~^Z - suspend ssh ~# - list forwarded connections ~& - background ssh (when waiting for connections to terminate) ~? - this message ~~ - send the escape character by typing it twice (Note that escapes are only recognized immediately after newline.)

Run TOP in Color, split 4 ways for x seconds - the ultimate ps command. Great for init scripts
One of my favorite ways to impress newbies (and old hats) to the power of the shell, is to give them an incredibly colorful and amazing version of the top command that runs once upon login, just like running fortune on login. It's pretty sweet believe me, just add this one-liner to your ~/.bash_profile -- and of course you can set the height to be anything, from 1 line to 1000! $ G=$(stty -g);stty rows $((${LINES:-50}/2));top -n1; stty $G;unset G Doesn't take more than the below toprc file I've added below, and you get all 4 top windows showing output at the same time.. each with a different color scheme, and each showing different info. Each window would normally take up 1/4th of your screen when run like that - TOP is designed as a full screen program. But here's where you might learn something new today on this great site.. By using the stty command to change the terminals internal understanding of the size of your terminal window, you force top to also think that way as well. # save the correct settings to G var. $ G=$(stty -g) # change the number of rows to half the actual amount, or 50 otherwise $ stty rows $((${LINES:-50}/2)) # run top non-interactively for 1 second, the output stays on the screen (half at least) $ top -n1 # reset the terminal back to the correct values, and clean up after yourself $ stty $G;unset G This trick from my [ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html bash_profile ], though the online version will be updated soon. Just think what else you could run like this! Note 1: I had to edit the toprc file out due to this site can't handle that (uploads/including code). So you can grab it from [ http://www.askapache.com/linux-unix/bash-power-prompt.html my site ] Note 2: I had to come back and edit again because the links weren't being correctly parsed

kill a process(e.g. conky) by its name, useful when debugging conky:)

Restart Xen XAPI
Restarts the XAPI service on the host, mostly used by Xen Center. It does not affect any running VMs, just the Xen client tools that may be connected. On my list as XAPI frustratingly keeps running out of memory and getting killed off.

edit hex mode in vim
return to normal mode from hex mode :%!xxd -r

display systemd log entries for sshd using "no-pager" (a bit like in pre-systemd: grep sshd /var/log/messages)
In pre-systemd systems, something like: "# grep sshd /var/log/messages" would display log events in /var/log/messages containing "sshd". # journalctl -u sshd --no-pager The above command displays similar results for systemd systems. (Note that this needs to be run with root permissions to access the log data.)

Get all shellcode on binary file from objdump
Better than the others, and actually works unlike some of them.

Quickly batch resize images
-geometry (preserves values of height and width given, and aspect ratio). WARNING: While 'resize' creates resized copies of original files, 'mogrify' works on the original files, replacing them. It will overwrite the source files, use with caution, and backup regularly.

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"


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