Which terminal command to get just IP address and

问题:

I'm trying to use just the IP address (inet) as a parameter in a script I wrote.

Is there an easy way in a unix terminal to get just the IP address, rather than looking through ifconfig?

回答1:

You can write a script that only return the IP like:

/sbin/ifconfig eth0 | grep 'inet addr' | cut -d: -f2 | awk '{print $1}'

For MAC:

ifconfig | grep "inet " | grep -v 127.0.0.1 | cut -d\  -f2

Or for linux system

hostname -i | awk '{print $3}' # Ubuntu 

hostname -i # Debian

回答2:

This will give you all IPv4 interfaces, including the loopback 127.0.0.1:

ip -4 addr | grep -oP '(?<=inet\s)\d+(\.\d+){3}'

This will only show eth0:

ip -4 addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}'

And this way you can get IPv6 addresses:

ip -6 addr | grep -oP '(?<=inet6\s)[\da-f:]+'

Only eth0 IPv6:

ip -6 addr show eth0 | grep -oP '(?<=inet6\s)[\da-f:]+'

回答3:

Generally, it is never guaranteed that a system will only have one IP address, for example, you can have both an ethernet and wlan connections, and if you have an active VPN connection then you'll have yet another IP address.

Linux

On Linux, hostname -I will list the current IP address(es). Relying on it always returning just one IP address will most likely not work as expected under some scenarios (i.e. a VPN link is up), so a more reliable way would be converting the result to an array and then loop over the elements:

ips=($(hostname -I))

for ip in "${ips[@]}"
do
    echo $ip
done

OSX

On OSX, if you know the interface, you could use:

~$ ipconfig getifaddr en0
192.168.1.123

which will return just the IP address.

Or you could loop over possible interface names, starting with a suffix, i.e. en:

for NUMBER in $(seq 0 5); do
    ip=`ipconfig getifaddr en$NUMBER`
    if [ -n "$ip" ]; then
        myip="$ip"
        break
    fi
done

echo $myip

Also, getting the IP address becomes non-deterministic in case both a cable and wifi connections are established, when a machine has more than one ethernet interfaces, or when VPN tunnels are present.

Getting the external IP

If you need the external IP, then you can query a text-mode service, for example curl ipecho.net/plain would return a plain text external IP.

回答4:

On latest Ubuntu versions (14.04 - 16.04), this command did the trick for me.

hostname -I | awk '{print $1}'

回答5:

hostname -I  

This command will give you the exact ip address as you want in Ubuntu.

回答6:

If you have limited environment, you may use this command:

ip -4 addr show dev eth0 | grep inet | tr -s " " | cut -d" " -f3 | head -n 1

回答7:

Command ifconfig is deprected and you should use ip command on Linux.

Also ip a will give you scope on the same line as IP so it's easier to use.

This command will show you your global (external) IP:

ip a | grep "scope global" | grep -Po '(?<=inet )[\d.]+'

All IPv4 (also 127.0.0.1):

ip a | grep "scope" | grep -Po '(?<=inet )[\d.]+'

All IPv6 (also ::1):

ip a | grep "scope" | grep -Po '(?<=inet6 )[\da-z:]+'

回答8:

We can simply use only 2 commands ( ifconfig + awk ) to get just the IP (v4) we want like so:

On Linux, assuming to get IP address from eth0 interface, run the following command:

/sbin/ifconfig eth0 | awk '/inet addr/{print substr($2,6)}'

On OSX, assumming to get IP adddress from en0 interface, run the following command:

/sbin/ifconfig en0 | awk '/inet /{print $2}'

回答9:

I wanted something simple that worked as a Bash alias. I found that hostname -I works best for me (hostname v3.15). hostname -i returns the loopback IP, for some reason, but hostname -I gives me the correct IP for wlan0, and without having to pipe output through grep or awk. A drawback is that hostname -I will output all IPs, if you have more than one.

回答10:

To get only the IP address on Mac OS X you can type the following command:

ipconfig getifaddr en0

回答11:

That would do the trick in a Mac :

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

That resolved to ping 192.168.1.2 in my machine.

Pro tip: $(...) means run whatever is inside the parentheses in a subshell and return that as the value.

回答12:

Use the following command:

/sbin/ifconfig $(netstat -nr | tail -1 | awk '{print $NF}') | awk -F: '/inet /{print $2}' | cut -f1 -d ' '

回答13:

Here is my version, in which you can pass a list of interfaces, ordered by priority:

getIpFromInterface()
{
    interface=$1
    ifconfig ${interface}  > /dev/null 2>&1 && ifconfig ${interface} | awk -F'inet ' '{ print $2 }' | awk '{ print $1 }' | grep .
}

getCurrentIpAddress(){
    IFLIST=(${@:-${IFLIST[@]}})
    for currentInterface in ${IFLIST[@]}
    do
        IP=$(getIpFromInterface  $currentInterface)
        [[ -z "$IP" ]] && continue
    echo ${IP/*:}
    return
    done
}

IFLIST=(tap0 en1 en0)
getCurrentIpAddress $@

So if I'm connected with VPN, Wifi and ethernet, my VPN address (on interface tap0) will be returned. The script works on both linux and osx, and can take arguments if you want to override IFLIST

Note that if you want to use IPV6, you'll have to replace 'inet ' by 'inet6'.

回答14:

I always wind up needing this at the most unexpected times and, without fail, wind up searching for threads like this on SO. So I wrote a simple script to get IPv4 addresses via netstat, called echoip - you can find it here. The bash for network addresses looks like this, it also gets your public address from ipecho.net:

IPV4='\d+(\.\d+){3}'
INTERFACES=`netstat -i | grep -E "$IPV4" | cut -d ' ' -f 1`
INTERFACE_IPS=`netstat -i | grep -oE "$IPV4"`

for i in "${!INTERFACES[@]}"; do
  printf "%s:\t%s\n" "${INTERFACES[$i]}" "${INTERFACE_IPS[$i]}"
done

The echoip script yields an output like this:

$ echoip
public: 26.106.59.169
en0:    10.1.10.2

回答15:

use this one line script: ifconfig | grep "inet " | grep -v 127.0.0.1|awk 'match($0, /([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)/) {print substr($0,RSTART,RLENGTH)}' mac & linux (tested in ubuntu) both works.

回答16:

In man hostname there is even more easier way which automatically excluding loopback IP and showing only space separated list of all assigned to host ip addresses:

root@srv:~# hostname --all-ip-addresses
11.12.13.14 192.168.15.19 

root@srv:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
   link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   inet 127.0.0.1/8 scope host lo
   inet6 ::1/128 scope host 
   valid_lft forever preferred_lft forever
2: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
  link/void 
  inet 11.12.13.14/32 scope global venet0:0
  inet 192.168.15.19/32 scope global venet0:1

回答17:

ip addr|awk '/eth0/ && /inet/ {gsub(/\/[0-9][0-9]/,""); print $2}'

shows all your ips

回答18:

On Redhat 64bit, this solved problem for me.

ifconfig $1|sed -n 2p|awk '{ print $2 }'|awk -F : '{ print $2 }'

回答19:

You can also use the following command:

ip route | grep src

NOTE: This will only work if you have connectivity to the internet.

回答20:

curl ifconfig.co 

This returns only the ip address of your system.

回答21:

I would Use Hostname -L to get just the IP to use as a variable in a script.