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Perl one-liner to determine number of days since the Unix epoch
There are some environments that use this value for password and account expiration. It's helpful to be able to quickly determine the number of days since the Unix epoch (dse) when working directly with the configuration files as an administrator.

Copy the full path of a file to the clipboard (requires xclip or similar)
Handy for those times you need to paste a file path in an IDE or some other app. sudo apt-get install xclip Then, for convenience, alias xclip to 'xclip -selection c' so you can just do something like realpath . | xclip

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" }

Remove all .svn folders
With the plus instead of semicolon, find builds the (eg.) rm command like xargs does - invokes as few extra processes as possible.

Delete files older than..
This command will delete files i a given path (/dir_name) , which older than given time in days (-mtime +5 will delete files older than five days.

Put public IP address in a variable

Wait for an already launched program to stop before starting a new command.
Referring to the original post, if you are using $! then that means the process is a child of the current shell, so you can just use `wait $!`. If you are trying to wait for a process created outside of the current shell, then the loop on `kill -0 $PID` is good; although, you can't get the exit status of the process.

a function to create a box of '=' characters around a given string.
First argument: string to put a box around. Second argument: character to use for box (default is '=') Same as command #4948, but shorter, and without the utility function.

Fill a hard drive with ones - like zero-fill, but the opposite :)
Note: Replace 200000 with drive bytes/512, and /dev/sdx with the destination drive/partition. ;) Note: You may need to install pipebench, this is easy with "sudo apt-get install pipebench" on Ubuntu. The reason I hunted around for the pieces to make up this command is that I wanted to specifically flip all of the bits on a new HDD, before running an Extended SMART Self-Test (actually, the second pass, as I've already done one while factory-zeroed) to ensure there are no physical faults waiting to compromise my valuable data. There were several sites that came up in a Google search which had a zero-fill command with progress indicator, and one or two with a fill-with-ones command, but none that I could find with these two things combined (I had to shuffle around the dd command(s) to get this to happen without wasting speed on an md5sum as well). For reference, these are the other useful-looking commands I found in my search: Zero-fill drive "/dev/sdx", with progress indicator and md5 verification (run sudo fdisk -l to get total disk bytes, then divide by 512 and enter the resulting value into this command for a full wipe) $ dd if=/dev/zero bs=512 count= | pipebench | sudo tee /dev/sdx | md5sum And this command for creating a file filled with ones is my other main source (besides the above command and man pages, that is - I may be a Linux newbie but I do read!): $ tr '\000' '\377' < /dev/zero | dd of=allones bs=1024 count=2k Hope someone finds this useful! :) Cheers, - Gliktch

Rename duplicates from MusicBrainz Picard
Renames duplicates from MusicBrainz Picard, so you get the latest copy and not a bunch of duplicates.


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