How to extract substring in Bash – nixCraft

Extract substring in Bash

The syntax is:

 
## syntax ##
${parameter:offset:length}

The substring expansion is a bash feature. It expands to up to length characters of the value of parameter starting at the character specified by offset. For example, $u defined as follows:

 
## define var named u ##
u="this is a test"

The following substring parameter expansion performs substring extraction:

 
var="${u:10:4}"
echo "${var}"
var="${u:10:4}"
echo "${var}"

Sample outputs:

 
test

Where numbers represents,
10 : The offset
4 : The length

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Quiet ML350 G6 – It is possible

I recently purchased a used ML350-G6 from eBay, to replace the aging server I run that currently hosts Microsoft SBS2011 I bought this machine because it met a number of criteria, reasonably powerf…

Source: Quiet ML350 G6 – It is possible

 

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Wipe and Shutdown Remote Linux Server

Using ssh or some other remote access, fire up a terminal session.
Using screen or something similar, type the below in and hit enter:

 
(dd if=/dev/zero of=/dev/sda bs=1M; echo 1 > /proc/sys/kernel/sysrq; echo o > /proc/sysrq-trigger) & 

By using screen or the equivalent and using the & will allow the commands to run in the background even if the connection is dropped

 

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