flags.go

package main

import (
	"flag"
	"fmt"
	"os"
)

func getFlags() options {
	// sets help page for MCScan
const usage = `Usage of GoMCScan:
GoMCScan (-a targets) [-p PortRange] [-T Threads] [-t Timeout] [-o output]
Options:
	-h, --help prints help information
	-a, --targets IP address range to scan. Ex: 116.202.0.0/16,116.203.0.0/16
	-p, --ports port range to scan. (25565) Ex: 1337,25565-25570
	-T, --threads number of threads to use. (1000)
	-t, --timeout timeout in seconds. (3)
	-i, --input location for target file. (targets.txt)
	-o, --output output location for scan file. (out/scan.log)
	-F, --favicon enable saving of favicon images to output directory. (false)
`

	var config options
	flag.IntVar(&config.threads, "T", 1000, "number of threads to use")
	flag.IntVar(&config.threads, "threads", 1000, "number of threads to use")
	flag.IntVar(&config.timeout, "t", 1, "timeout in seconds")
	flag.IntVar(&config.timeout, "timeout", 1, "timeout in seconds")
	flag.BoolVar(&config.saveFavicon, "F", false, "enables favicon saving")
	flag.BoolVar(&config.saveFavicon, "favicon", false, "enables favicon saving")
	var addressRange string
	flag.StringVar(&addressRange, "a", "", "IP address range to scan")
	flag.StringVar(&addressRange, "targets", "", "IP address range to scan")
	flag.StringVar(&config.outputPath, "output", "out/scan.log", "output location for scan file")
	flag.StringVar(&config.outputPath, "o", "out/scan.log", "output location for scan file")
	var inputPath string
	flag.StringVar(&inputPath, "input", "targets.txt", "input location for target file")
	flag.StringVar(&inputPath, "i", "targets.txt", "input location for target file")
	var portRange string
	flag.StringVar(&portRange, "p", "25565", "port range to scan")
	flag.StringVar(&portRange, "port", "25565", "port range to scan")

	

	flag.Usage = func() { fmt.Print(usage) }
	flag.Parse()

	if isFlagPassed("a") || isFlagPassed("targets") { // if input fill is passed, set addressRange to the contents of the file
		config.addressList = expandAddress(addressRange)
	} else if _, err := os.Stat(inputPath); err == nil { //checks if input file exist, then reads it if it does
		b, err := os.ReadFile(inputPath)
		if err != nil {
			fmt.Print(err)
		}
		str := string(b)
		if str != "" { //checks if input file is empty
			addressRange = str
			config.addressList = expandAddress(addressRange)
		} else {
			handleError("Input file is empty.")
		}
	} else {
		handleError("targets have not been set and no input file found.")
	}

	config.portList = expandPort(portRange)
	return config
}

// Checks if a flag has been passed
func isFlagPassed(name string) bool {
	found := false
	flag.Visit(func(f *flag.Flag) {
		if f.Name == name {
			found = true
		}
	})
	return found
}