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Problem: I wanted to backup user data individually, using and incremental method. In this example, all user data is located in "/mnt/storage/profiles", and about 25 folders inside, each with a username ( /mnt/storage/profiles/mike; /mnt/storage/profiles/lucy ...)
I need each individual folder backed up, not the whole "/mnt/storage/profiles". So, using find while excluding directories depth and creating two variables (tarfile=username & desdir=destination), tar will create a .tgz file for each folder, resulting in a "mike_2013-12-05.tgz" and "lucy_2013-12-05.tgz".
Merge files, joining line by line horizontally.
Very useful when you have a lot of files where each line represents an info about an event and you want to join them into a single file where each line has all the info about the same event
See the example for a better understanding
You can install filterous with
$ sudo apt-get install libxslt1-dev; sudo easy_install -U filterous
Lots of scripts show you how to use socat to send an email to an SMTP server; this command actually emulates an SMTP server!
It assumes the client is only sending to one recipient, and it's not at all smart, but it'll capture the email into a log file and the client will stop retrying.
I used this to diagnose what emails were being sent by cron and subsequently discarded, but you can use it for all sorts of things.
It is helpful to know the current limits placed on your account, and using this shortcut is a quick way to figuring out which values to change for optimization or security.
Alias is:
$ alias ulimith="command ulimit -a|sed 's/^.*\([a-z]\))\(.*\)$/-\1\2/;s/^/ulimit /'|tr '\n' ' ';echo"
Here's the result of this command:
$ ulimit -c 0 -d unlimited -e 0 -f unlimited -i 155648 -l 32 -m unlimited -n 8192 -p 8 -q 819200 -r 0 -s 10240 -t unlimited -u unlimited -v unlimited -x unlimited
$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 155648
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 8192
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) unlimited
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
If colordiff utility installed, it is sometimes handy to call this command. Of course, you should create an alias for it. E.g. svndiff.
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video).
$ cat /proc/acpi/video/VGA/LCD/brightness
to discover the possible values for your display.
