[SOLVED] output IP into a file

NetRock · 05-10-2010, 10:35 AM

just to let you know:
when i do ifconfig on PC this is what i get (this is only a sample):

eth0 Link encap:Ethernet HWaddr 02:7y:74:lA:9p:46
inet addr:10.20.8.254 Bcast:10.20.15.255 Mask:255.255.240.0
blah....blah.....
blah....blah.....
blah....blah.....
blah....blah.....

grail · 05-10-2010, 10:44 AM

Code:

ifconfig eth0 | awk -F: 'NR==2{print $NF}'

I assume you can do the rest from here?
This should also give you a clue about the 4th line

NetRock · 05-10-2010, 10:50 AM

Thanks for your quick reply.
i will do the rest & let you know if i hit a WALL!!!

NetRock · 05-10-2010, 11:07 AM

Hi grail, the code

Quote:

ifconfig eth0 | awk -F: 'NR==2{print $NF}'

supposed to get the MASK Address? i tried it out by directing to a file & got nothing!!
i think i am doing something wrong???

NetRock · 05-10-2010, 11:12 AM

Sorry My BAD....!! it is working

NetRock · 05-10-2010, 01:02 PM

when we do at the prompt

myhost> whatmask 255.255.192.0

---------------------------------------------
TCP/IP SUBNET MASK EQUIVALENTS
---------------------------------------------
CIDR = .....................: /18
Netmask = ..................: 255.255.192.0
Netmask (hex) = ............: 0xffffc000
Wildcard Bits = ............: 0.0.63.255
Usable IP Addresses = ......: 16,382

we get the above info.

so, I used your code & directed the result to a file called it maskfile. copy the whatmask in tmp& then use the following:

Quote:

ipbits= `/tmp/whatmask "maskfile" | grep "CIDR=."| awk -F/'{print $2}'

but it does not work. i want to get the CIDR value only so after insert it at the end of the 4th ip address of the FileA send it to the new file.

i believe i still need your help, thank you.

SuperJediWombat! · 05-10-2010, 06:57 PM

Try this: http://tldp.org/LDP/abs/html/

grail · 05-10-2010, 09:36 PM

Well off hand I would go with:

Code:

ipbits=$(whatmask 255.255.192.0 | awk -F: '/CIDR/{print $2}')

NetRock · 05-10-2010, 10:18 PM

Hi grail thanks for your kind reply. i am searching how to feed subnetmask to "whatmask" program using a file. i will let you know once i found something.
thanks again for taking the time to help me.

grail · 05-10-2010, 10:23 PM

Quote:

i am searching how to feed subnetmask to "whatmask" program using a file.

Why? Is this for your own education? It does not seem like it would be required to place in a file and then retrieve back again.

NetRock · 05-10-2010, 10:41 PM

If you recall we have this code:

Quote:

ifconfig eth0 | awk -F: 'NR==2{print $NF}'

where we output only the subnetmask from ifconfig, by sending subnetmask to a file, we can use it by "whatmask" program,
to get the CIDR notation. after add CIDR to the ip address of the 4th line of FileA.
At the end, to have ex.: 192.168.0.0/16.
so for each ifconfig (on each pc) i must come up with this format: $ip.$ip.0.0/$cidr, then the custom made script will be able to assign the right ip address to each PC. after according to their ip addresses they have different roles on the domain. So, right IP address is important.

Thanks for your attention.

grail · 05-10-2010, 11:39 PM

Not sure whether you can pipe or should use command substitution as i do not have whatmask to experiment with, but one of these should do the trick:

Code:

ipbits=$(ifconfig eth0 | awk -F: 'NR==2{print $NF}' | whatmask | awk -F: '/CIDR/{print $2}')

#or

ipbits=$(whatmask $(ifconfig eth0 | awk -F: 'NR==2{print $NF}')| awk -F: '/CIDR/{print $2}')

#or if you want to be funky you could try

ipbits=$(ifconfig eth0 | awk -F: 'NR==2{print | "whatmask "$NF}' | awk -F: '/CIDR/{print $2}')

Let me know what works

NetRock · 05-11-2010, 08:14 AM

Good Morning All,

tried grail's last command (the FUNKY ONE), made small change as follow

needed space between whatmask & $NF)

Quote:

ipbits=$(ifconfig eth0 | awk -F: 'NR==2{print | "whatmask " " "$NF}' | awk -F: '/CIDR/{print $2}')

worked great. THANK YOU grail.

Nice work.

Now, i must output only the IP address of the 4th line of my FileA & add the CIDR at the end of the IP addr. with no space.
to get something like: 192.168.0.0/$ipbits (so 192.168.23.65 must become 192.168.0.0)

FileA:

Quote:

#this a comment
#this a comment
#this a comment
hostname 192.168.23.65
hostname 10.18.13.253
hostname 10.18.16.253
hostname 177.23.56.58
#this a comment

anymore FUNKY code to do this???

grail · 05-11-2010, 09:09 AM

If you go back through the posts I think you will see we already covered how to do this (hint: NR variable means Number of Records)

NetRock · 05-11-2010, 11:13 AM

i tried this:

Quote:

awk -F: 'NR==4{print $NF}' input_file | awk {x=gensub(/([0-9]+\.[0-9]+\.).*/,"\\10.0","g",$2);if(!_[x])print x > "file"}'

but got error...!!