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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"

Multiple variable assignments from command output in BASH
This version uses read instead of eval.

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" }

Bash: escape '-' character in filename
If you don't escape the - of the filename, you will get the command interpreting it as a parameter, returning (in the best case) an error.

View all date formats, Quick Reference Help Alias
If you have used bash for any scripting, you've used the date command alot. It's perfect for using as a way to create filename's dynamically within aliases,functions, and commands like below.. This is actually an update to my first alias, since a few commenters (below) had good observations on what was wrong with my first command. # creating a date-based ssh-key for askapache.github.com $ ssh-keygen -f ~/.ssh/`date [email protected]$HOSTNAME-%m-%d-%g` -C '[email protected]' $ # /home/gpl/.ssh/[email protected] # create a tar+gzip backup of the current directory $ tar -czf $(date +$HOME/.backups/%m-%d-%g-%R-`sed -u 's/\//#/g'

Mount/unmount your truecrypted file containers
This should automatically mount it to /media/truecrypt1. Further mounts will go to /media/truecrypt2, and so on. You shouldn't need sudo/su if your permissions are right. I alias tru='truecrypt' since tr and true are commands. To explicitly create a mount point do: tru volume.tc /media/foo To make sure an GUI explorer window (nautilus, et al) opens on the mounted volume, add: --explorer To see what you currently have mounted do: tru -l To dismount a volume do: tru -d volume.tc. To dismount all mounted volumes at once do: tru -d Tested with Truecrypt v6.3a / Ubuntu 9.10

Make changes in .bashrc immediately available
Any changes to BASH shell made in .bashrc will be active in the current terminal window from the moment you execute this command, ie. aliases, prompt settings etc. No need to restart terminal. (In BASH 'source' simile to 'eval' lets you generally execute any bunch of commands stacked in a text file).

load changes without logging in and out vim
src: daily vim blog

create ICO file with more than one image
requires imagemagick. -background transparent is of course optional.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.


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