The -f option (read source file)

This option is used to read the program source from the source file instead of in the first non-option argument. If this option is given multiple times, the program consists of the concatenation of the contents of each specified source file:

-f source-file

     --file=source-file

First, we will create 2 programs to print line number 2 and line number 4, respectively. Then, we will use the -f option to source those files for execution with the interpreter, as follows:

$ vi f1.awk
NR==2 { print NR, $0 }  
$ vi f2.
NR==4 { print NR, $0 }

Now, first use only f1. for sourcing:

$ awk -f f1.awk  cars.dat 

This can also be performed as follows:

awk --file=f1.awk cars.dat

The output on execution of this code is as follows:

2 honda           city        2005        60000       3

Now, we will source both the files together. AWK will concatenate the contents of the two sourced files and execute them on the cars.dat filename, as follows:

$ awk -f f1.awk -f f2.awk cars.dat

This can also be performed as follows:

$ awk --file=f1.awk --file=f2.awk  cars.dat

The output on execution of this code is as follows:

2 honda           city        2005        60000       3
4 chevy           beat        2005        33000       2