Parse ifconfig to get only my IP address using Bash

Question

I want to edit the bashrc file to have a simple function called \"myip\" to run. As you might guess, the function myip prints only my internal IP address of my machine.

Answer 1

Similar to JSR, but with awk and cut in reverse order:

my_ip=$(ifconfig en1 | grep 'inet addr' | awk '{print $2}' | cut -d: -f 2)
echo ${my_ip}

Answer 2

Both the following work here (CentOS 5).

ip addr show eth0 | awk '$1 == "inet" {gsub(/\/.*$/, "", $2); print $2}'

ifconfig eth0 | awk '/inet addr/ {gsub("addr:", "", $2); print $2}'

For OS X (v10.11 (El Capitan) at least):

ifconfig en0 | awk '$1 == "inet" {print $2}'

Answer 3

No need to do unportable ifconfig parsing in Bash. It's a trivial one-liner in Python:

python -c 'import socket; print(socket.gethostbyname(socket.gethostname()))'

Answer 4

Taking patch's answer, making it a bit more general,

i.e.: skipping everything till the first digit.

ifconfig eth0 | awk '/inet addr/{sub(/[^0-9]*/,""); print $1}'

Or even better:

ifconfig eth0 | awk '/inet /{sub(/[^0-9]*/,""); print $1}'

• Please note the print part at the end - changes from $2 to $1.

Using Perl Regex:

ifconfig eth0 | grep -oP '(?<= inet addr:)[^ ]+'

Explanation: grep -oP searches for an EXACT match using Perl regex.
The "tricky" part is the regex itself;
1. (?<= inet addr:) means - that the string inet addr: is to the LEFT of what we're looking for.
2. [^ ]+ (please notice the space after the ^ ) - it means to look for everything until the first blank - in our case it is the IP Address.

Answer 5

This code outputs IP addresses for all network connections (except loopback) and is portable between most OS X and Linux versions.

It's particularly useful for scripts that run on machines where:

• The active network adapter is unknown,
• notebooks that switch between Wi-Fi and Ethernet connections, and
• machines with multiple network connections.

The script is:

/sbin/ifconfig -a | awk '/(cast)/ {print $2}' | cut -d: -f2

This can be assigned to a variable in a script like this:

myip=$(/sbin/ifconfig -a | awk '/(cast)/ {print $2}' | cut -d: -f2)

Scripts can handle possible multiple addresses by using a loop to process the results, as so:

if [[ -n $myip ]]; then
  count=0
  for i in $myip; do
    myips[count]=$i       # Or process as desired
    ((++count))
  done
  numIPaddresses=$count   # Optional parameter, if wanted
fi

Notes:

• It filters 'ifconfig' on "cast", as this has an added effect of filtering out loopback addresses while also working on most OS X and Linux versions.
• The final 'cut' function is necessary for proper function on Linux, but not OS X. However, it doesn't effect the OS X results - so it's left in for portability.

Answer 6

After trying some solutions i find this most handy, add this to your alias:

alias iconfig='ifconfig | awk '\''{if ( $1 >= "en" && $2 >= "flags" && $3 == "mtu") {print $1}; if ( $1 == "inet" || $1 == "status:"){print $0};}'\''|egrep "en|lo|inet"'

the output looks like this:

shady@Shadys-MacBook-Pro:xxxx/xxx ‹dev*›$ iconfig lo0: inet 127.0.0.1 netmask 0xff000000 en0: inet 10.16.27.115 netmask 0xffffff00 broadcast 10.16.27.255 en1: en2: en5: inet 192.168.2.196 netmask 0xffffff00 broadcast 192.168.2.255