[lug] Download file from a remote system

Zan Lynx zlynx at acm.org
Mon Feb 9 16:49:51 MST 2009


Kenneth D Weinert wrote:
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> 
> Carl Wagner wrote:
> 
>> I would like to be able to automatically dial into a remote box (modem
>> only) and retrieve a file periodically (cron) say every 4-6 hours.
>> The file would be a few K-bytes in size, that I could compress down to
>> probably less than 1KB.  (It's temperature data).
> 
> Would a straight up scp work?  You could set it up so you don't need to
> log in (by copying credentials) and it's basically just a copy of a file
> after that.

No, scp relies on TCP/IP already running, which would require running 
PPP over a modem link.  Doable, but a lot of useless overhead in my opinion.

I would go with UUCP, unless setting up pppd is easier for you.  I have 
to admit, I only touched UUCP once or twice way back in some intro to 
Unix class 15+ years ago.

You could probably cobble up something using Kermit, X/Y/Zmodem or 
similar, that would always launch the transmit program on the same 
filename whenever the modem dials in.  UUCP would be more flexible though.

Basically, you set up a terminal program to listen on the serial port 
where the modem is and provide either a shell login, or a PPP login. 
With the shell login, the shell would be the UUCP program or another 
file transfer.

I've used mgetty for the terminal program for pppd and it worked well. 
It is flexible enough to do anything else you would need.  Don't forget 
to dig out an AT command reference so that you can set the codes to 
disable +++ escapes and such.

-- 
Zan Lynx
zlynx at acm.org

"Knowledge is Power.  Power Corrupts.  Study Hard.  Be Evil."



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