Fast command-line program which displays connectivity

skorpan · 2009-06-07 16:16:43

Hi

I'm looking for a command-line program which can show whether or not my network interface has an IP address or not. It could use "ifconfig" to extract the information, I don't really care, but it has to be *fast* and it cannot require root access.

Thanks

.:B:. · 2009-06-07 16:23:48

What's so wrong with ifconfig itself then?

skorpan · 2009-06-07 16:30:22

The thing is that I will be writing an xmobar plugin which will simply run this command and do something special depending on whether I have an IP or not.

madalu · 2009-06-07 16:35:26

What about the following?

ifconfig wlan0 | grep -w inet

Obviously you'll need to substitute your own wireless interface for
wlan0.

If you have an IP address you'll get a result. If you don't you won't.

Last edited by madalu (2009-06-07 16:36:16)

skorpan · 2009-06-07 16:37:30

Thanks, but if someone knows some sed/awk magic to get only the interface's IP address, that would be great!

EDIT:
Using the little "sed" I know, this is what I came up with:

ifconfig wlan0 | grep -w inet | sed "s/^\\s*//" | sed "s/^inet addr://" | sed "s/\\s.*//"

EDIT2:
Now I have this reasonable command:

ifconfig wlan0 | grep -w inet | sed "s/.*inet addr:\([^ ]*\).*.*/\1/"

Last edited by skorpan (2009-06-07 16:44:19)

Procyon · 2009-06-07 17:14:28

Does this work?

tail -n1 /proc/net/arp | cut -d' ' -f1

skorpan · 2009-06-07 17:17:45

Procyon wrote:

Does this work?

tail -n1 /proc/net/arp | cut -d' ' -f1

Unfortunately, that's not my IP address (at least not on my machine), but the IP address of the gateway.

Procyon · 2009-06-07 19:05:18

Ah yeah, I didn't look carefully at it.

BTW sed can do something cool with the t command, if the substitution failed it can print something else

ifconfig eth0 | sed -n '1{s/.*inet addr:\([0-9.]*\).*/\1/p;t;s/.*/Disconnected/p}'

whipsch · 2009-06-07 21:01:56

[will@ghastly ~]$ ifconfig | grep inet | awk '{print $2}' | cut -d':' -f2
192.168.1.12
127.0.0.1

Arch Linux

#1 2009-06-07 16:16:43

Fast command-line program which displays connectivity

#2 2009-06-07 16:23:48

Re: Fast command-line program which displays connectivity

#3 2009-06-07 16:30:22

Re: Fast command-line program which displays connectivity

#4 2009-06-07 16:35:26

Re: Fast command-line program which displays connectivity

#5 2009-06-07 16:37:30

Re: Fast command-line program which displays connectivity

#6 2009-06-07 17:14:28

Re: Fast command-line program which displays connectivity

#7 2009-06-07 17:17:45

Re: Fast command-line program which displays connectivity

#8 2009-06-07 19:05:18

Re: Fast command-line program which displays connectivity

#9 2009-06-07 21:01:56

Re: Fast command-line program which displays connectivity

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