Factorial in Awk

Welcome to the Factorial in Awk page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

function usage() {
    print "Usage: please input a non-negative integer"
    exit(1)
}

function str_to_number(s) {
    return (s ~ /^\s*[+-]*[0-9]+\s*$/) ? s + 0 : "ERROR"
}

function factorial(n,  f) {
    f = 1
    while (n >= 2) {
        f *= n
        n--
    }

    return f
}

BEGIN {
    if (ARGC < 2) {
        usage()
    }

    result = str_to_number(ARGV[1])
    if (result == "ERROR" || result < 0) {
        usage()
    }

    print factorial(result)
}

Factorial in Awk was written by:

• rzuckerm

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.