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====== Grep - Grep IP address accurately ======

Let's say we have one log file named logfile.log that contains a few lines like below:

<file bash logfile.log>
192.168.1.1
192.168.1.10
192.168.1.11
192.168.1.111
</file>

When we want to search for 192.168.1.1, we usually will use:

<code bash>
grep 192.168.1.1 logfile.log

192.168.1.1
192.168.1.10
192.168.1.11
192.168.1.111
</code>

But unfortunately the result is not as what we expected(I assume we expect only 192.168.1.1 will come out) because grep will show to us all results "containing" the pattern given by us.

To overcome this problem, we have to use grep like this:

<code bash>
grep "192.168.1.1\>" logfile.log

192.168.1.1
</code>

Do not forget to put the double quotes, if not the command will not show any result.


An alternative way to achieve the above result is by using **-w** flag of grep. 

<code bash>
grep -w 192.168.1.1 logfile.log

192.168.1.1
</code>