Display IP in a shell script

Scormen · 04-10-2009, 07:28 AM

Hi all,

I'm writing a little shell script, but it I'm having a little problem.

The script has to write a other script, this is what I have:

Code:

echo "
 INTIPP=$(which ifconfig) | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print \$1}'
 echo ${INTIPP}
" > /script.sh

That's quite useless, I know, but is only a piece of the script

When I look into /script.sh, I see this:

Code:

 INTIPP=/sbin/ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'
 echo

Thats wrong, behind "echo", there should be my IP address.

When I execute the command $(which ifconfig) | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}' in a terminal, it works. But not from the script.

Any idea?

Thanks,
Kris

Nylex · 04-10-2009, 07:41 AM

INTIPP=`$(which ifconfig) | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print \$1}'`
echo $INTIPP

should do it. Basically, when you use echo, anything in double quotes is taken to be a string, unless there's a $, in which case the variable is substituted with its value. You can't assign to variables inside an echo.

Scormen · 04-10-2009, 07:50 AM

Thanks for your answer, Nylex!

But, the output is then:

Code:

 INTIPP=192.168.2.198
 echo

The output on "the first rule" should realy hold the command itself, also in the output, because when using DHCP, each time running /script.sh, the IP will be different.

So, in /script.sh the output should have to be something like this:

Quote:

INTIPP=/sbin/ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'
192.168.2.5

To say it in other words:
The first script have to make a script (/script.sh).
/script.sh has to display the IP address.
Because the IP address is received from a DHCP, it is always different, so it should be echoed by a command.

Thanks,
Kris

Scormen · 04-10-2009, 08:03 AM

I got it

The first script is:

Code:

#!/bin/bash
echo "
#!/bin/bash
 INTIPP=\`$(which ifconfig) | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print \$1}'\`
 echo \${INTIPP}
" > /script.sh

This will make /script.sh like this:

Quote:

#!/bin/bash
INTIPP=`/sbin/ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1}'`
echo ${INTIPP}

When executing /script.sh, it will return the IP address.

Thanks for the help!
Kris