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nmap fast scan all ports target

Get the current svn branch/tag (Good for PS1/PROMPT_COMMAND cases)
Get the svn info, grep for the "URL" of the repository, pull out the tag/branch/trunk, and then just show the helpful/meaningful bit.

Make a ready-only filesystem ?writeable? by unionfs
First look into /etc/modules if you have unionfs (or squashfs) support. If not, add the modules. UnionFS combines two filesystems. If there is a need to write a file, /tmp/unioncache will be used to write files (first create that directory). Reads will be done where the file is found first. http://tldp.org/HOWTO/SquashFS-HOWTO/creatingandusing.html

Remind yourself every 15 minutes (repeated reminders)
Note: 1) -n option of watch accepts seconds 2) -t option of notify-send accepts milliseconds 3) All quotes stated in the given example are required if notification message is more than a word. 4) I couldn't get this to run in background (use of & at the end fails). Any suggestions/improvements welcome.

Don't spam root. Log your cronjob output to syslog
This command will log the output of your simple cronjobs to syslog, and syslog will take it from there. Works great for monitoring scripts which only produce simple output. Advantages: * This can be used by regular users, without modifying system files like /etc/syslog.conf * Reduce cron spam to root@localhost (Please stop spaming the sysadmins) * Uses common tools like syslog (and logrotate) so that you don't need to maintain yet another krufty logfile. * Still ensures that the output is logged somewhere, for posterity. Perhaps it's stored the secure, central syslog server, for example. * Seems to work fine on Ubuntu, CentOS, FreeBSD & MacOSX

Display or use a random file from current directory via a small bash one-liner
An other way to run it ( playing a random file ending with avi, flv or mpeg ) from a specified dir and a specified type of extension : making MOVIE array with a glob : $ MOVIE=( /PATH/TO/MY/FAVORITE/MOVIES/*.{avi,flv,mpeg} ) playing the random file from a random key from the array $ mplayer ${MOVIE[ RANDOM % ( ${#i[@]} + 1 ) ]]} I use only globs and a bash array. I use GNU bash, version 3.2.48

Get the Volume labels all bitlocker volumes had before being encrypted
Get information of volume labels of bitlocker volumes, even if they are encrypted and locked (no access to filesystem, no password provided). Note that the volume labels can have spaces, but only if you name then before encryption. Renaming a bitlocker partition after being encrypted does not have the same effect as doing it before.

Realtime apache hits per second
Change the cut range for hits per 10 sec, minute and so on... Grep can be used to filter on url or source IP.

See udev at work
See how your system works with pendrives/mice/monitors/whatever-you-can-plug-in. Use cases: see on which /dev/... your peripherals are, find out if a specific udev rule is being applied correctly.

move messages directly from one IMAP inbox to another
This one-liner was useful in helping someone I know to get off of MS Exchange. `mailutil` proved to be a much better alternative than `fetchmail` or `getmail` in this case. It quickly moved all mails to the destination server (a simple Dovecot/Maildir setup), with no need to convert back and forth between mbox/maildir on the user's own system.


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