Commands by knoppix5 (66)

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Benchmark SQL Query
Benchmark a SQL query against MySQL Server. The example runs the query 10 times, and you get the average runtime in the output. To ensure that the query does not get cached, use `RESET QUERY CACHE;` on top in the query file.

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"

Typing the current date ( or any string ) via a shortcut as if the keys had been actually typed with the hardware keyboard in any application.
That works in all softs, CLI or GUI... I don't want to waste time to all the time typing the same stuff . So, I have that command in my window manager shortcuts ( meta+l ). All the window managers have editable shortcuts AFAIK. If not, or you don't want to use it that way, you can easily use the xbindkeys soft. I you're using kde4, you can run : $ systemsettings then open "inputs actions" and create a new shortcut. For Gnome take a look there : http://www.cyberciti.biz/faq/howto-create-keyboard-shortcuts-in-gnome/ A more advanced one, with strings and newlines : $ xvkbd -xsendevent -text "---8

add files to existing growable DVD using growisofs
replace "directory name with files to add to DVD" with actual directory containing files you want to add to growable DVD

Recurse through directories easily
This is a simple case of recursing through all directories, adding the '.bak' extension to every file. Of course, the 'cp $file $file.bak' could be any code you need to apply to your recursion, including tests, other functions, creating variables, doing math, etc. Simple and clean recursion.

Create passwords and store safely with gpg
Adjust the $ head -c part for password length. I use filenames like "hans@commandlinefu.com.gpg" and a vim which automatically decrypts files with .gpg suffixes.

Cut the first 'N' characters of a line
You can also cut charactes starting from X to N.

diff will usually only take one file from STDIN. This is a method to take the result of two streams and compare with diff. The example I use to compare two iTunes libraries but it is generally applicable.
diff is designed to compare two files. You can also compare directories. In this form, bash uses 'process substitution' in place of a file as an input to diff. Each input to diff can be filtered as you choose. I use find and egrep to select the files to compare.

tree by modify time with newest file at bottom
Go look at sample output first This is kind of like the ls command but displays by modify time with size, date and color. The newest files at the bottom of the screen (reverse using tac)

Use bash history with process substitution
Bash has a great history system of its commands accessed by the ! built-in history expansion operator (documented elsewhere on this site or on the web). You can combine the ! operator inside the process redirection


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