Re: passing environment variables back to shell

[Shawn Lamson <shawn.lamson@verizon.net>]

On Mon, June 23 at 11:05 PM EDT
Matt Price <matt.price@utoronto.ca> wrote:

> Hi,
> 
> anyone know if it's possible to pass the value of variables assigned
> within a bash script back out to the executing shell?  Or better yet,
> to all subsequent shells?
> 
> I've written a tiny script to figure out the IP address of my
> (dynamically assigned) home computer and pass it to ipmasq on my work
> computer.  I would like to run this as a cron job (probably daily,
> since my IP is pretty stable) and only rerun ipmasq if the new IP
> address differs from the old one.  But I don't understand howto pass
> the new value back out to the executing environment.
> 
> I think if you look at the script you'll see what I'm trying to do... 
> 
> /usr/local/scripts/gethomeip :
> -------------------------------------------
> #!/bin/bash
> HOSTRESULT=`host youknowwho.dyndns.org`
> RESULTIP=`echo ${HOSTRESULT##[^0-9]*[^0-9\.]}`
> 
> # check the initial values
> echo "$RESULTIP"
> echo "$MATTSIP"
> if [ "$RESULTIP" = "$MATTSIP" ]
>  then
> echo "no problem, the address is up to date"
> else
> 
> #set the new value 
> MATTSIP=$RESULTIP
> echo "$MATTSIP"
> 
> # export -- but of course it only exports to daughter processes, not
> parent processes export MATTSIP
> ipmasq
> fi
> 
> # check to make sure the variables been set within the script
> echo "$MATTSIP"
> 
> -----------------------------------------------
> 
> obviously export isn't what I'm looking for.  Any ideas what I ought
> to substitute there?  thanks,

slamson@callerio:/tmp$ cat return3 
#!/bin/bash
echo ONE
echo TWO
echo THREE
slamson@callerio:/tmp$ set $(sh ./return3 ); echo :$1: :$2: :$3:
:ONE: :TWO: :THREE:


This passes them out.  They won't have the names you specified,
though.  Why not just run ipmasq from within the script, though?

HTH


> 
> matt
> 
> 


Shawn Lamson
shawn.lamson@verizon.net
Debian GNU/Linux 3.0