This question is ideal in my case: Ludisposed's python-scapy-tcp-port-scan-of-subnet - At codereview stackexchange
But this is not Scapy; nor Python(it might get used in the future though but that is another question! - it is in bash - and as he(or she) stated:
Will be working on Threading later on, so that is not under review.
my case is similar.
I have been using
GNU-parallel with this bash script. As well as
-Which will maybe come up as another, review question. Maybe a follow up to this one.
I want any thoughts - or pointers - that could improve this code (or the way I chose to do it)
Or if there's a better approach in general?
Example of anything related to that might be - Maybe I should use double quotes (at some place/(s)) instead of single quotes;
Use other "things" that is - maybe something else than a for loop (just as a example of what I mean)
this below is a bit of context
- Maybe parentheses - so maybe it would make sense to (parenthesize when things go "okay" (that is
&&) and vice versa (
- as it is quite simple already; it is maybe hard to simplify it even more (so this is not really under "consideration" but warmly welcomed!)
and some context
It should be noted I plan to extend this, with GNU-Parallel and in conjunction with Nmap - among other things. Redirect I/O (input/output), to files - read from those files and so on. Maybe find correlations between this data(data mining) (that is; multiple nodes in a network; perform analysis on all hosts that has port X open and port Y filtered - how many is Windows, how many is BSD, (...))
- Stability of the code, Robustness.
- Readability(for this small code this might be funny but I'll extend this later :) and therefore want to get it right from the start (after many of my mistakes I have made previously)
- Might be unclear here but; security. I hope I am following not only the guidelines and all good-practice - but also writing securely.
#!/usr/bin/env bash ## shebang from the below sources # https://stackoverflow.com/a/10383546/14346786 # https://stackoverflow.com/questions/10376206/what-is-the-preferred-bash-shebang export A=0 # start of the port range export B=53 # end of the port range for p in $(seq $A $B); do timeout 1s bash -c '</dev/tcp/192.168.1.1/'$p'' && echo "[+] $p open" || echo "[-] $p closed/filtered/timed out" done
I struggled a lot previously ( awhile ago I confused
-c "" (..) and confused quotes; && - and so on) but now it is working; which is why I went here - And really (hopefully successfully)
really simplified it into 1 or 2 lines. (to make it so easy to read as possible)
I have tried (and plan on using in the future):
- C program
- Python(mostly v.3)
- Nmap (to so-called
enumeratethe (supposedly open) ports (what services, what versions of these services, ...)
(excluding extended versions of this where - maybe if a port(80 or HTTPS) is open; I will use the
GETcommand to grab the HTML from the remote host) or, a similar case - where waiting is included)
I should've mentioned That I searched this site for dev tcp (and bash) but it came few results,