Programming Forums > Script Programming > Python

Riddle · Jul 27th, 2005, 1:30 AM

Well.. a friend asked for help with a Python port scanner he was working on, and I tweaked it and came up with this. I tried commenting the semi-confusing or interesting parts so you socket-noobs can understand it (I say "tried," because I'm not very good at explaining myself.

) Anyway, do you have any ideas as to what I could do to make it better? Thanks in advance.

(Toggle Plain Text)

import socket
target= raw_input("Target: ")
startport= input("Starting port: ")
endport= input("Ending port: ")
for port in range(startport,endport + 1):
#I have '+ 1' because range() ends one number under the second argument.
  scan = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  scan.settimeout(1)
  if not scan.connect_ex((target, port)):
#connect_ex would return a number higher than zero had it failed, so 'not' is appropriate.
    print "Port",port,"is open."
    scan.close()

Riddle · Jul 27th, 2005, 5:38 AM

Okay I've updated it, with a logging function.. now it appends all open ports to a file. This is the code to do that:

(Toggle Plain Text)

log= file("scan_log.log","a")
log.write("Open ports for %s:\n" % target)
#the next line should be within the for loop. I had to use %s because write() wanted a string.. and port was (obviously) an int.
log.write("%s\n" % port)
#and this should be outside of the for loop (last line)
log.close()

Sane · Jul 28th, 2005, 8:04 PM

Quote:

#the next line should be within the for loop. I had to use %s because write() wanted a string.. and port was (obviously) an int.
log.write("%s\n" % port)

If you wanted it a string, why not:

log.write(str(port)+'\n')

=S

Edit: Oh were you saying you had to use %s as opposed to %d?

Riddle · Jul 28th, 2005, 8:14 PM

I hadn't thought of that.

Yes I was saying I had to use %s instead of %d. Had I been using printf() in C++, I would have used %d... but I'm not sure how much of a difference it makes in Python.

Either way, it works.

Cerulean · Jul 29th, 2005, 4:59 PM

Quote:

If you wanted it a string, why not:

log.write(str(port)+'\n')

Bear in mind that constructing strings with the + operator is slower than using string formatting, as it needs to construct intermediate strings as it goes along. Not that it matters in 99.9% of the cases, it's just nice to know if you really need to optimize.

Quote:

Yes I was saying I had to use %s instead of %d. Had I been using printf() in C++, I would have used %d... but I'm not sure how much of a difference it makes in Python.

Either way, it works.

You don't need anything other than %s. I don't like using %d in Python as you have to worry about another exception being raised if the item is not a number. Using %s implicitly calls str() on the item. You'll always get pretty formatting of your variable, and not have to waste time remembering other characters - something that tends to interrupt work flow.

Jul 27th, 2005, 1:30 AM	#1
Riddle Programmer Join Date: May 2005 Location: Nar Shaddaa Posts: 42 Rep Power: 0	Very simple Python port scanner. Well.. a friend asked for help with a Python port scanner he was working on, and I tweaked it and came up with this. I tried commenting the semi-confusing or interesting parts so you socket-noobs can understand it (I say "tried," because I'm not very good at explaining myself. ) Anyway, do you have any ideas as to what I could do to make it better? Thanks in advance. (Toggle Plain Text) import socket target= raw_input("Target: ") startport= input("Starting port: ") endport= input("Ending port: ") for port in range(startport,endport + 1): #I have '+ 1' because range() ends one number under the second argument. scan = socket.socket(socket.AF_INET, socket.SOCK_STREAM) scan.settimeout(1) if not scan.connect_ex((target, port)): #connect_ex would return a number higher than zero had it failed, so 'not' is appropriate. print "Port",port,"is open." scan.close() import socket target= raw_input("Target: ") startport= input("Starting port: ") endport= input("Ending port: ") for port in range(startport,endport + 1): #I have '+ 1' because range() ends one number under the second argument. scan = socket.socket(socket.AF_INET, socket.SOCK_STREAM) scan.settimeout(1) if not scan.connect_ex((target, port)): #connect_ex would return a number higher than zero had it failed, so 'not' is appropriate. print "Port",port,"is open." scan.close()

Jul 27th, 2005, 5:38 AM	#2
Riddle Programmer Join Date: May 2005 Location: Nar Shaddaa Posts: 42 Rep Power: 0	Okay I've updated it, with a logging function.. now it appends all open ports to a file. This is the code to do that: (Toggle Plain Text) log= file("scan_log.log","a") log.write("Open ports for %s:\n" % target) #the next line should be within the for loop. I had to use %s because write() wanted a string.. and port was (obviously) an int. log.write("%s\n" % port) #and this should be outside of the for loop (last line) log.close() log= file("scan_log.log","a") log.write("Open ports for %s:\n" % target) #the next line should be within the for loop. I had to use %s because write() wanted a string.. and port was (obviously) an int. log.write("%s\n" % port) #and this should be outside of the for loop (last line) log.close()

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Jul 28th, 2005, 8:14 PM	#4
Riddle Programmer Join Date: May 2005 Location: Nar Shaddaa Posts: 42 Rep Power: 0	I hadn't thought of that. Yes I was saying I had to use %s instead of %d. Had I been using printf() in C++, I would have used %d... but I'm not sure how much of a difference it makes in Python. Either way, it works.

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Programming Forums > Script Programming > Python

Very simple Python port scanner.