My Linksys router (BEFSR41) connects to my DSL modem.
My ISP provides a "dynamic" IP. Sometimes I want to
know that IP (or want a script to know, actually).
I use:

lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm

and pipe that to sed to extract the IP from the one
line (of 69) that contains it.

I wonder whether there is resource-cheaper way to get
the page from the router than firing up lynx every time.
Be nice, too, if there were a way to get just the one line.

I'm on a G5 running OSX, but this is really a bash/unix
question, I guess.

TIA & Cheers, N.

--

In article <91bkm2-kh6.ln1@news.amhuinnsuidhe.net>,
Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:

> My Linksys router (BEFSR41) connects to my DSL modem.
> My ISP provides a "dynamic" IP. Sometimes I want to
> know that IP (or want a script to know, actually).
> I use:
>
> lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm
>
> and pipe that to sed to extract the IP from the one
> line (of 69) that contains it.
>
> I wonder whether there is resource-cheaper way to get
> the page from the router than firing up lynx every time.
> Be nice, too, if there were a way to get just the one line.
>
> I'm on a G5 running OSX, but this is really a bash/unix
> question, I guess.
>
> TIA & Cheers, N.
>
> --

Here is what I use:

curl -s http://www.WhatIsMyIP.com | awk '
match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
print substr($0,RSTART,RLENGTH)
exit
}
'

Or to capture that in a variable:

IP=$(curl -s http://www.WhatIsMyIP.com | awk '
match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
print substr($0,RSTART,RLENGTH)
exit
}
')
echo $IP

But it is still a invoking a script that invokes command. In this case
I use curl instead of lynx. I also use whatismyip.com

Bob Harris

On 2005.05.28 01:15:36,
the amazing <nospam.News.Bob@remove.Smith-Harris.us> declared:

> In article <91bkm2-kh6.ln1@news.amhuinnsuidhe.net>,
> Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:
>
>> My Linksys router (BEFSR41) connects to my DSL modem.
>> My ISP provides a "dynamic" IP. Sometimes I want to
>> know that IP (or want a script to know, actually).
>> I use:
>>
>> lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm
>>
>> and pipe that to sed to extract the IP from the one
>> line (of 69) that contains it.
>>
>> I wonder whether there is resource-cheaper way to get
>> the page from the router than firing up lynx every time.
>> Be nice, too, if there were a way to get just the one line.
>>
>> I'm on a G5 running OSX, but this is really a bash/unix
>> question, I guess.
>>
>> TIA & Cheers, N.
>>
>> --
>
> Here is what I use:
>
> curl -s http://www.WhatIsMyIP.com | awk '
> match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
> print substr($0,RSTART,RLENGTH)
> exit
> }
> '
>
> Or to capture that in a variable:
>
> IP=$(curl -s http://www.WhatIsMyIP.com | awk '
> match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
> print substr($0,RSTART,RLENGTH)
> exit
> }
> ')
> echo $IP
>
> But it is still a invoking a script that invokes command. In this case
> I use curl instead of lynx. I also use whatismyip.com
>
> Bob Harris

Thanks! Curl is what I wanted; it's a tenth the size
of lynx, so using it should be significantly faster.
Curl has a "--range <N-M>" option (retrieve only bytes
N to M of the document), which would have been useful,
but my router doesn't seem to support such requests.

My knowledge of awk is very limited, so I'll stick
with sed for now to extract the IP from the retrieved
document.

Cheers, N.
--

In article <91bkm2-kh6.ln1@news.amhuinnsuidhe.net>,
Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:

> My Linksys router (BEFSR41) connects to my DSL modem.
> My ISP provides a "dynamic" IP. Sometimes I want to
> know that IP (or want a script to know, actually).
> I use:
>
> lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm
>
> and pipe that to sed to extract the IP from the one
> line (of 69) that contains it.
>
> I wonder whether there is resource-cheaper way to get
> the page from the router than firing up lynx every time.
> Be nice, too, if there were a way to get just the one line.
>
> I'm on a G5 running OSX, but this is really a bash/unix
> question, I guess.

See the man page for ifconfig

In article <7trom2-t4g.ln1@news.amhuinnsuidhe.net>,
Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:

> On 2005.05.28 01:15:36,
> the amazing <nospam.News.Bob@remove.Smith-Harris.us> declared:
>
> > In article <91bkm2-kh6.ln1@news.amhuinnsuidhe.net>,
> > Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:
> >
> >> My Linksys router (BEFSR41) connects to my DSL modem.
> >> My ISP provides a "dynamic" IP. Sometimes I want to
> >> know that IP (or want a script to know, actually).
> >> I use:
> >>
> >> lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm
> >>
> >> and pipe that to sed to extract the IP from the one
> >> line (of 69) that contains it.
> >>
> >> I wonder whether there is resource-cheaper way to get
> >> the page from the router than firing up lynx every time.
> >> Be nice, too, if there were a way to get just the one line.
> >>
> >> I'm on a G5 running OSX, but this is really a bash/unix
> >> question, I guess.
> >>
> >> TIA & Cheers, N.
> >>
> >> --
> >
> > Here is what I use:
> >
> > curl -s http://www.WhatIsMyIP.com | awk '
> > match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
> > print substr($0,RSTART,RLENGTH)
> > exit
> > }
> > '
> >
> > Or to capture that in a variable:
> >
> > IP=$(curl -s http://www.WhatIsMyIP.com | awk '
> > match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
> > print substr($0,RSTART,RLENGTH)
> > exit
> > }
> > ')
> > echo $IP
> >
> > But it is still a invoking a script that invokes command. In this case
> > I use curl instead of lynx. I also use whatismyip.com
> >
> > Bob Harris
>
> Thanks! Curl is what I wanted; it's a tenth the size
> of lynx, so using it should be significantly faster.
> Curl has a "--range <N-M>" option (retrieve only bytes
> N to M of the document), which would have been useful,
> but my router doesn't seem to support such requests.
>
> My knowledge of awk is very limited, so I'll stick
> with sed for now to extract the IP from the retrieved
> document.
>
> Cheers, N.
> --

Awk, sed, perl, whatever works.

If you are interested in awk, here is a very good introductory web page
that is not too long but gives a surprisingly good explanation of awk:

<http://h30097.www3.hp.com/docs/base_..._HTML/ARH9WBTE
/WKXXXXXX.HTM>

In this case, the awk is rather simple. The basic form of an awk script
is multiple

pattern_selection { action on lines matching pattern }

entries.

match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/)

is the pattern. It is just looking for any line that contains a string
of the form n.n.n.n, so 123.456.7.89 would match the regular expression
pattern of /[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/

The $0 is the awk variable that contains the current line being
processed.

I used match because it will pre-load a couple of awk variables with the
location of the found string and its length, which is useful for the
action phase of the pattern{action} pair.

... {
print substr($0,RSTART,RLENGTH)
exit
}

is the action if match finds something. print is obvious. The substr()
is again working on the awk variable $0 which is the current line where
we found the n.n.n.n pattern. RSTART and RLENGTH are pre-loaded by the
match command. So I'm extracting the n.n.n.n pattern from the current
line and printing it.

Since I have found what I'm looking for, I exit the awk script and stop
processing any additional lines from the curl output.

Bob Harris

On 2005.05.29 14:01:36,
the amazing <srhi@comcast.net> declared:

> In article <91bkm2-kh6.ln1@news.amhuinnsuidhe.net>,
> Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:
>
>> My Linksys router (BEFSR41) connects to my DSL modem.
>> My ISP provides a "dynamic" IP. Sometimes I want to
>> know that IP (or want a script to know, actually).
>> I use:
>>
>> lynx -auth=user:pass -dump http://192.168.1.1/Status_Router.htm
>>
>> and pipe that to sed to extract the IP from the one
>> line (of 69) that contains it.
>>
>> I wonder whether there is resource-cheaper way to get
>> the page from the router than firing up lynx every time.
>> Be nice, too, if there were a way to get just the one line.
>>
>> I'm on a G5 running OSX, but this is really a bash/unix
>> question, I guess.
>
> See the man page for ifconfig

I believe that ifconfig will only show my machine's
local network address, 192.168.1.<2-254>. What I need
is the IP address my router has on the internet,
65.95.120.148 right now.

--

On Mon, 30 May 2005 07:07:44 -0400,
Nollaig MacKenzie <nollaig@amhuinnDELETEsuidheCAPS.net> wrote:
> I believe that ifconfig will only show my machine's
> local network address, 192.168.1.<2-254>. What I need
> is the IP address my router has on the internet,
> 65.95.120.148 right now.

wget -q -O- http://www.whatismyip.com/ | grep 'Your IP' |
awk '{print $5}' | head -1

(unwrap this ; it is a single line of commands)

Greets,
Robert
--
/^"- '-(\__/)-' -"^\
'-.' oo '.-' Holy Jesus! What are these god**** animals?!
`-..-'
Finger rvdm@db.debian.org for my GPG key.