know more about 'awk ' command ..

We have seen many times 'awk' command is used frequently in Linux shell scripts. But, nobody knows it's meaning and never try to know it, I am also included in this list:). That's why it's my small attempt to focus on 'awk' command ....

The awk command combines the functions of grep and sed, making it one of the most powerful  Linux command

. Using 'awk' command,  you can substitute words from an input file's lines for words in a template  or perform calculations on numbers within a file. 
   It is mostly used with 'print' command...

 The general form of the awk command is

awk <pattern> '{print <stuff>}' <file>

Example.

Let's assume that file test.txt contains following  word: 

stone hammer wood
ball bat car

Now we'll use the print function in awk to plug the words from each input line into a template, like this:

 

awk '{print "Hit the",$1,"with your",$2}' test.txt
 

Hit the stone with your hammer
Hit the pedal with your foot

Test script that uses 'awk' command

#!/bin/bash
load=`cat /proc/loadavg|awk {' print $1 '}`
date=`date`
disp=$date.$load
echo $disp|tee -a loadavg.tx 

1. cat /proc/loadavg will display following o/p

[root@server ~]# cat /proc/loadavg
0.15 0.56 0.31 1/84 2696
[root@server ~]#


2. By using awk {' print $1 '}` , we will cut first column ($1)

[root@server ~]# cat /proc/loadavg|awk {' print $1 '}
0.15
[root@server ~]#

Hope you would understand it..