So, I'm using a CentOS VM in VirtualBox, and created four new disks in the SCSI controller.

The VM created the folders:

/dev/sda

/dev/sdb

/dev/sdc

/dev/sdd

Using a 'for loop' all disks are partitioned for LVM.

It's useful when you cannot access your env (systemd) or the process DISPLAY variable is not set. Perhaps also when you have a multi-head/user configuration.

Many times I give the same commands in loop to find informations about a file. I use this as an alias to summarize that informations in a single command. Now with variables! :D

perl version of "Wait for file to stop changing"

When "FileName" has not been changed for last 10 seconds, then print "DONE"

"10" in "(stat)[10]" means ctime.

One have other options like atime, mtime and others. http://perldoc.perl.org/functions/stat.html

This loop will finish if a file hasn't changed in the last 10 seconds.

.

It checks the file's modification timestamp against the clock.

If 10 seconds have elapsed without any change to the file, then the loop ends.

.

This script will give a false positive if there's a 10 second delay between updates,

e.g. due to network congestion

.

How does it work?

'date +%s' gives the current time in seconds

'stat -c %Y' gives the file's last modification time in seconds

'$(( ))' is bash's way of doing maths

'[ X -lt 10 ]' tests the result is Less Than 10

otherwise sleep for 1 second and repeat

.

Note: Clever as this script is, inotify is smarter.

s/espeak/say/ on a mac

alternatively, run the spinner for 5 seconds:

timeout 5 bash -c 'spinner=( Ooooo oOooo ooOoo oooOo ooooO oooOo ooOoo oOooo); while true; do for i in ${spinner[@]}; do for j in seq 0 ${#i}; do echo -en "\b\b"; done; echo -ne "${i}"; sleep 0.2; done; done'

(here is character '+' repeated 80 times)

Sometimes needed to enhance the title of the script.

Working with lists of IP addresses it is sometimes useful to summarize a count of how many times an IP address appears in the file.

This example, summarizeIP, uses another function "verifyIP" previously defined in commandlinefu.com to ensure only valid IP addresses get counted. The summary list is presented in count order starting with highest count.

This command will create a popup reminder window to assist in remembering tasks

http://i.imgur.com/2n7viiA.png is how it looks when created

This method does not transfer the contents of the entire file, instead it computes a md5 sum of the file on each end so that large files can be compared without transferring them across the net.

I used this fragment with Imagemagick convert so that I can place long text strings in pictures. The "\n" gets converted to a true newline in the image.

So this fragment uses fold command to wrap the line and then sed to convert newlines (and any trailing spaces on the line) to the text "\n"

After you run this script, you can check status for broken symlink with this command:

find -L . -type l

The leading plus sign is removed - Minus sign is left intact

usage = crontest "/path/to/bin"

This version of this function will echo back the entire command so it can be copied/pasted to crontab. Should be able to be automagically appended to crontab with a bit more work. Tested on bash and zsh on linux,freebsd,aix

Generates labyrinth-like pattern on UTF-8 terminal in bash.

For fun ;)

If you have a client that connects to a server via plain text protocol such as HTTP or FTP, with this command you can monitor the messages that the client sends to the server. Application level text stream will be dumped on the command line as well as saved in a file called proxy.txt.

You have to change 8080 to the local port where you want your client to connect to. Change also 192.168.0.1 to the IP address of the destination server and 80 to the port of the destination server.

Then simply point your client to localhost 8080 (or whatever you changed it to).

The traffic will be redirected to host 192.168.0.1 on port 80 (or whatever you changed them to).

Any requests from the client to the server will be dumped on the console as well as in the file "proxy.txt".

Unfortunately the responses from the server will not be dumped.

hypnotizing pendulum

Thanks to the great grml team for this func!

You really should look at their shell configs for further usefull things!

http://git.grml.org/?p=grml-etc-core.git;a=blob_plain;f=etc/grml/script-functions;h=4d6bcea8f9beae83abd08f44155d299ea54a4a9f;hb=HEAD

# {{{ check for availability of program(s)

# usage example:

# check4progs [-s,-q,--quiet,--silent] arg [arg .... argn]

#

# with option given either of:

# -s,-q,--quiet,--silent

#

# check for available progs but produce no output

check4progs() {

[ -n "${ZSH_VERSION}" ] && emulate -L sh

local RTN=0

local oldifs="${IFS}"

local ARG d found

local VERBOSE=1

case ${1} in

-q | -s | --quiet | --silent)

VERBOSE=0

shift 1

;;

*)

;;

esac

while [ $# -gt 0 ]

do

ARG="$1"

shift

found=0

IFS=:

for d in $PATH

do

if [ -x "${d}/${ARG}" ]

then

found=1

break

fi

done

IFS="${oldifs}"

# check for availability

if [ ${found} -eq 0 ]

then

if [ ${VERBOSE} -eq 1 ]

then

printf "%s: binary not found\n" "${ARG}" >&2

fi

RTN=1

fi

done

# return non zero, if at least one prog is missing!

return $RTN

}

# }}}

seems a useless command ...