Python Port Scanner

Like the whois shell script I posted recently the Python port scanner below is another script I've had lying around on my computer for  while. I wrote it when I was first learning Python and its socket API.

#!/usr/bin/env python
from socket import * 

if __name__ == '__main__':
    target = raw_input('Enter host to scan: ')
    targetIP = gethostbyname(target)
    print 'Starting scan on host ', targetIP

    #scan reserved ports
    for i in range(20, 1025):
        s = socket(AF_INET, SOCK_STREAM)

        result = s.connect_ex((targetIP, i))

        if(result == 0) :
            print 'Port %d: OPEN' % (i,)

Example usage:

~$ ./
Enter host to scan: localhost
Starting scan on host
Port 22: OPEN
Port 80: OPEN
Port 139: OPEN
Port 445: OPEN
Port 631: OPEN

The code could easily be extended to allow the user to specify what ports to scan, or to take the hostname as a command line argument.

Posted on 29 Mar 2008
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