mawk

Implementation of programming language AWK

mawk is AWK interpreter written in C by Mike Brennan. It is considered to be the most efficient implementation of AWK and is system default on Ubuntu/Debian Linux.

mawk implements POSIX 1003.2 standard of the language and has a number of useful extensions.

Examples:

Hello, World!:

Example for versions gawk 3.1.6, mawk 1.3.3

The printing is done with BEGIN pattern, i.e., before processing the input. 

BEGIN { print "Hello, World!" }

Factorial:

Example for versions gawk 3.1.6, mawk 1.3.3

This example uses iterative factorial definition. Individual statements within code block can be separated with semicolons (;) or new lines. 

BEGIN {
    f = 1
    print "0! = " f
    for (i=1; i<17; i++) {
        f *= i
        print i "! = " f
    }
}

Fibonacci numbers:

Example for versions gawk 3.1.6, mawk 1.3.3

This example uses iterative definition of Fibonacci numbers. fib is an associative array, and pr is a string. 

BEGIN {
    fib[1] = 1
    fib[2] = 1
    for (i=3; i<17; i++)
        fib[i] = fib[i-1]+fib[i-2]
    pr = ""
    for (i=1; i<17; i++)
        pr = pr fib[i] ", "
    print pr "..." 
}

Quadratic equation:

Example for versions gawk 3.1.6, mawk 1.3.3 
{   A = $1
    B = $2
    C = $3
    if (A == 0) 
        print "Not a quadratic equation"
    else
    {   D = B*B-4*A*C
        if (D == 0)
            print "x = " (-B/2/A)
        else if (D > 0)
        {   print "x1 = " ((-B+sqrt(D))/2/A)
            print "x2 = " ((-B-sqrt(D))/2/A)
        }
        else
        {   print "x1 = (" (-B/2/A) "," (sqrt(-D)/2/A) ")"
            print "x1 = (" (-B/2/A) "," (-sqrt(-D)/2/A) ")"
        }
    }
}