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Hi there,
I was wondering if anyone can give some advise/tips on this. My goal is to figure out the broadcast address. The way I think I should do is:

  • get/detect the IP address and the subnet mask or CIDR
  • convert the mask to binary form
  • count the number of tailing 0s and apply the formula: m=2^n, where n is the number of the 0s
  • replace the last bit of the IP address with the the number: m-1

and that should be the broadcast address.

My question is: what's the best way of getting [or detect] the IP address and subnet mask? Having said that, I mean which is OS independent. I can use "ifconfig" to figure out that info but again "ifconfig" implementation varies from distro to distro and definitely that not gonna work on windows. I tried using socket.gethostbyname(socket.gethostname()) and also socket.gethostbyname(socket.getfqdn()) but that doesn't return the correct IP address if the "/etc/hosts" file is not properly written. Otherwise it returns the loop back address. I'm stuck here. I'm sure there must be a better way of doing this. Anyone out here got something for me?
Thanks in advance. Cheers!!!

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hi slate,
Thanks for trying to help me out.
Actually my problem is not with calculation but with the with getting the IP itself, in the first place. I didn't know about ipcalc though, but it seems like one need to know the IP and the subnet mask/CIDR first to use it. I've already [kinda] solved that part. But ipcalc gonna make my job lot easier, for sure. Cheers!!!

Edited by MacUsers because: n/a
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Just for the future reference, in case anyone else is also looking for the same thing, I'm answering to my own question. I found this solution and it works on OS X and Linux.

## broadcast address
osSys = "uname -s"
BSD = "ifconfig | grep -w broadcast | cut -d\  -f 6"
LNX = "ip -o addr show | grep -w inet | grep -e eth | cut -d\  -f 9"
#
if commands.getoutput(osSys) == "Linux":
    bCast = commands.getoutput(LNX)
elif commands.getoutput(osSys) == "Darwin":
    bCast = commands.getoutput(BSD)
else:
    print "System not supported!!"
    sys_exit()

Hope this helps. cheers!!

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