Commands by casidiablo (2)

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strips the first field of each line where the delimiter is the first ascii character

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Selecting a random file/folder of a folder
I used only shuf command.

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"

Clean way of re-running bash startup scripts.
This replaces the current bash session with a new bash session, run as an interactive non-login shell... useful if you have changed /etc/bash.bashrc, or ~/.bashrc If you have changed a startup script for login shells, use $ exec bash -l Suitable for re-running /etc/profile, ~/.bash_login and ~/.profile. edit: chinmaya points out that $ env - HOME=$HOME TERM=$TERM bash -s "exec bash -l" will clear any shell variables which have been set... since this verges on unwieldy, might want to use $ alias bash_restart='env - HOME=$HOME TERM=$TERM bash -s "exec bash -l"'

Enable ** to expand files recursively (>=bash-4.0)
Since bash 4.0, you can use ** to recursively expand to all files in the current directory. This behaviour is disabled by default, this command enables it (you'd best put it in your .profile). See the sample output for clarification. In my opinion this is much better than creating hacks with find and xargs when you want to pass files to an application.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

delete multiple files with spaces in filenames (with confirmation)
ls -Q will show the filenames in quotes. xargs -p rm will print all the filenames piped from ls -Q and ask for confirmation before deleting the files. without the -Q switch, if we have spaces in names, then the files won't be deleted.

prevent accidents while using wildcards
alternative for "echo rm *.txt". Just doubletab the command you are willing to use and it will show you the affected files.

silent/shh - shorthand to make commands really quiet
Sometimes I just want to run a command quietly but all that keyboard shifting makes my fingers hurt. This little function does the job eg.: $ if shh type less; then PAGER=less; fi


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