Linux / Unix: Awk Print Variable

How do I print variables using Awk interpreted programming language under Linux or Unix like operating systems?

Tutorial details
Difficulty	Easy (rss)
Root privileges	No
Requirements	awk

Awk pattern scanning and processing language. It is small, fast, and simple. It has a clean syntax and most useful for text processing. awk has built-in variables that are automatically set. For example, $0 variable holds the entire current input line. In this example, print hello world using awk:

 
echo 'Hello world' | awk '{ print $0 }'

Sample outputs:

Hello world

In this following example, pass two values to awk to print addition:

 
echo 3 4 | awk '{ print $1 + $2 }'

Sample outputs:

To print third word from input, enter:

 
echo This is a test |awk '{print $3}'

Sample outputs:

Printing a text file

Create a file called foo.txt:
$ cat foo.txt
Sample outputs:

Holding on to anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned.
In a controversy the instant we feel anger we have already ceased striving for the truth, and have begun striving for ourselves.

To print the entire file line by line, enter:

 
awk '{ print }' foo.txt

 
awk '{ print $0 }' foo.txt

awk define and print variable

Create a variable called x and y:

 
awk 'BEGIN{x=3; y=4;}END{ print "x=" x " and y=" y}'</dev/null

To print total of x and y, enter:

 
echo|awk 'BEGIN{x=3; y=4; total=0}{ total= x+y}END{ print x " + " y " = " total }'

Sample outputs:

Say hello to printf

To format and print use a printf statement. The printf works like c printf.

 
echo Total 5000.5686 | awk '{ printf "%s $%.2f\n", $1, $2 }'

Sample outputs:

Total $5000.57

See awk man page for more details:
$ man awk

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Linux / Unix: Awk Print Variable

Printing a text file

awk define and print variable

Say hello to printf

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