why python output doesn't save correctly

Question

i'm trying to save output of a python code that actually it has written with os.system

import os
os.system("sudo nmap -p5433 -P0 -oG - -sS 127.0.0.1 | \
    sed -n 's/.* \([0-9\.]\{7,\}\).*\/open\/.*/\1/p' > result.txt")

As you can see at the end of a line,output should be save in "result.txt" and i'm sure the output should be an ip (127.0.0.1) but the output is something like this:

the output is a symbol or something like that,is there any way that i can save the output of this code correctly?

Have you tested your commandline function without the python wrapper? Because there seems to be hardly anything in the python part that can go wrong. — Kraay89, Dec 24 '20 at 12:42
Is there a specific reason, why you run nmap as sudo? It could be, that the process asks for a sudo password and therefore doesn't complete — NationBoneless, Dec 24 '20 at 15:10
I've tested your script without the 'sed' part and it works correctly. — SergeiMinaev, Dec 24 '20 at 18:58
yes it works but i need that part. because i just need the ip address in result @SergeiMinaev — Erfan jafari, Dec 24 '20 at 21:32
What are you using the sed command for? I can't make sense of your command. You are using nmap on the specific port 5433, with an old version of no ping (newer would be -Pn instead of -P0), outputting it in greppable format, with a TCP SYN Scan. Then you are using sed and trying to replace something in your lines, but I can't figure out what — NationBoneless, Dec 25 '20 at 13:08
This does not appear to be a python problem at all. You might get better help tagging this question differently, or even asking on a different stackexchange site such as serverfault or superuser. If you want to treat this as a python problem, do the processing and writing in python instead of sed/sh. — MisterMiyagi, Dec 25 '20 at 13:20

score 0 · Accepted Answer · answered Dec 25 '20 at 13:15

If I understood you correctly, you want to save only hosts, that are found in your nmap scan and have status up?

If so you could use:

sudo nmap -p5433 -P0 -oG - -sS 127.0.0.1 | grep 'Up' | grep -oP '\d*\.\d*\.\d*\.\d* > result.txt'

You use nmap, then you grep all lines, containing the Up status, then you only grep the ip-addresses and put them in the text file

If you just want all ip, addresses that return in the scan (without status Up check) you can simplify:

sudo nmap -p5433 -P0 -oG - -sS 127.0.0.1 | grep -oP '\d*\.\d*\.\d*\.\d*' > result.txt

Although there will be duplicates if nmap prints something like:

# Nmap 7.80 scan initiated Fri Dec 25 14:05:05 2020 as: nmap -p5433 -P0 -oG - -sS 127.0.0.1
Host: 127.0.0.1 (localhost) Status: Up
Host: 127.0.0.1 (localhost) Ports: 5433/closed/tcp//pyrrho///

As there are two lines with the same ip address

why python output doesn't save correctly

1 Answers1