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tar copy
Just a copy of a big dir when you wan't things like ownership and date etc etc to be untouched. Note: Updated with the ideas from "mpb".

put an unpacked .deb package back together
If any changes have been made to the package while it was unpacked (ie, conffiles files in /etc modi‐fied), the new package will inherit the changes. This way you can make it easy to copy packages from one computer to another, or to recreate packages that are installed on your system, but no longer available elsewhere. Note: dpkg-repack will place the created package in the current directory.

Create user add lines from partial passwd file
Handy if you are installing a new server or recovering an old one and you have a passwd file with the accounts you want to add to the server. If you edit the file so that only the accounts that you want to add are left this line will spit out the correct useradd lines. The uid, gecos and shell will be preserved.

Get a list of the erroring cifs entries in fstab
It disturbs me when my logwatch report tells me a share or machine has disappeared, esp as mount isn't telling me what's gone. This command outputs to stderr the erroring cifs entries from fstab.

Filter the output of a file continously using tail and grep

Simple multi-user encrypted chat server for 5 users
Client ~$ ncat --ssl localhost 9876 Change localhost to the correct ip address.

Create a .png from a command output and upload to ompdlr.org, give URI
Create a .png from output command or whatever, the upload and give URI from ompdlr.org

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" }

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"

Random play a mp3 file
Pick a mp3 at random and play it. Assumes the availability of locate with an updated db and mpg123 Not the most useful command I guess, but all of the really useful ones are taken...


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