CIDR to netmask is straightforward if tedious -- just binary math. Shells aren't generally that good at it but modern BASH has large enough numbers to handle this.
If you have an older bash, it may generate negative values due to overflowing its 32-bit integers.
Awesome! Thanks Corona688 for the script. It's not what I'm looking for, but the script is good.
Here is my actual question, I've rephrased it and created separate topic for this.
please let me know that in unix using c programming language we can do binary to string conversion and vice versa using ltoa and atol but how can we do it in c++ programming language.
thank you in advance. (3 Replies)
Hello,
can sed be used to convert all letters of a file from uppercase to lowercase and vice versa?i know tr command can be used but with sed is it possible?
i came up with this :-
sed 'y///' file1
actually the above command is also not working! Please help me. Thanks in advance :) (6 Replies)
Hi,
I have a pdf file. i want to convert it to text file and do some work on it and later want to convert it back to pdf. Can this be done via unix?
or
Is there a way unix can directly work on PDF file? (2 Replies)
Hi,
I am new to Unix and discovered this example problem online that I believe will help my learning:
Run the command's below
env >> xx
env >> xx
env >> xx
env >> xx
env >> xx
You will now have a file called XX with the env redirected into it 5 times
Create a script named... (2 Replies)
i am thinking of replacing my vista with ubuntu.
Questions:
1) what will be the advantages and disadvantages of using ubuntu instead of vista?
2) what will be the setbacks of replacing my vista?
3) how hard is it to cope up with the new OS? what must i learn to utilize ubuntu? (1 Reply)
Hi
I have a system PRIMARY where I can push or pull files to/from STANDBY using scp. I can also ssh without entering a password.
On the STANDBY system if I try and use scp or ssh it asks for a password.
I checked in ~/.ssh and there was no authorized_keys file on the PRIMARY server. After... (2 Replies)
I need to write a script that will take the input from a file and convert the number from centigrade to fahrenheit and vice versa.
This is what I have but it doesn't seem to be correct.
Also the data file has 11 numbers inside of it and the output needs to be listed as so:
Fahrenheit Temperature... (18 Replies)
Hi all,
I installed Oracle virtual box 4.1.8 on my desktop. I installed Windows 2008 server R2 as one instance and Solaris 10 as another instance. When am trying to ping from Windows to solaris and vice-versa, ping not working.
windows IP : 10.1.47.24
Solaris IP : 10.1.47.25
netstat... (2 Replies)
Hi,
In unix or linux is there any command exist to identify Host Name to IP Address or Vice Versa?
Thanks in advance (6 Replies)
Discussion started by: nag_sathi
6 Replies
LEARN ABOUT DEBIAN
netmask
NETMASK(1) Debian Linux NETMASK(1)NAME
netmask - a netmask generation and conversion program
SYNOPSIS
netmask [ options ] spec [ spec ... ]
DESCRIPTION
This program accepts and produces a variety of common network address and netmask formats. Not only can it convert address and netmask
notations, but it will optimize the masks to generate the smallest list of rules. This is very handy if you've ever configured a firewall
or router and some nasty network administrator before you decided that base 10 numbers were good places to start and end groups of
machines.
OPTIONS -h, --help
Print a summary of the options
-v, --version
Print the version number
-d, --debug
Print status/progress information
-s, --standard
Output address/netmask pairs
-c, --cidr
Output CIDR format address lists
-i, --cisco
Output Cisco style address lists
-r, --range
Output ip address ranges
-x, --hex
Output address/netmask pairs in hex
-o, --octal
Output address/netmask pairs in octal
-b, --binary
Output address/netmask pairs in binary
-n, --nodns
Disable DNS lookups for addresses
DEFINITIONS
A spec is an address specification, it can look like:
address
One address.
address1:address2
All addresses from address1 to address2.
address1:+address2
All addresses from address1 to address1+address2.
address/mask
A group starting at address spanning mask.
An address is an internet network address, it can look like:
ftp.gnu.org
An internet hostname.
209.81.8.252
A standard dotted quad internet address notation.
100 A decimal number (100 in this case).
0100 An octal number preceded by "0" (64 in this case).
0x100 A hexadecimal number preceded by "0x" (256 in this case).
A mask is a network mask, it can look like:
255.255.224.0
A dotted quad netmask (netmask will complain if it is not a valid netmask).
0.0.31.255
A Cisco style inverse netmask (with the same checks).
8 The number of bits set to one from the left (CIDR notation).
010 The number of bits set to one from the left in octal.
0x10 The number of bits set to one from the left in hexadecimal.
AUTHOR
netmask was written by Robert Stone. Some algorithm design and optimization was provided by Tom Lear. This manual page was written by
Robert Stone.
BUGS
Let me know if you find any. This man page is a bit more simplistic than I'd like, but I've forgotten most of the groff I once knew.
SEE ALSO ipchains(1), ipfwadm(8), netstat(8), route(8), routed(8), gated(8), tcpd(8)Debian Project 15 May 1999 NETMASK(1)