[350] in linux-announce channel archive
Poor Man's Mirror 1.6
daemon@ATHENA.MIT.EDU (Lars Wirzenius)
Tue Mar 28 01:02:21 1995
Date: Tue, 28 Mar 1995 07:50:26 +0300
From: Lars Wirzenius <wirzeniu@cc.helsinki.fi>
To: linux-activists@niksula.hut.fi, linux-announce@vger.rutgers.edu
X-Mn-Key: announce
From: dsnyder@netcom.com (David C. Snyder)
Subject: Poor Man's Mirror 1.6
Keywords: mirror archive ftp distribution
Newsgroups: comp.os.linux.announce
Organization: ?
Approved: linux-announce@news.ornl.gov (Lars Wirzenius)
Followup-to: comp.os.linux.misc
/----------------------------------------------------------------------------\
| |
| The Poor Man's Mirror Script |
| |
+----------------------------------------------------------------------------+
| |
| tpircS rorriM s'naM rooP ehT |
| |
\----------------------------------------------------------------------------/
Introduction
I am announcing the availability of a couple of smallish perl scripts that
can be used to maintain an up to date copy of any archive directory
structure that is available from a UNIX host via anonymous ftp. These
scripts can be used to maintain an archive on your PC even if your only
internet connection is via a dial-up UNIX shell account. These scripts
are particularly useful for ftp'ing a Linux distribution from one of the
mirror sights and modeming it down to your PC. If you choose to do this,
please do so during off peak hours for the archive site!
Features
- The remote script (the one that runs on the PC at home) works under
Linux or under DOS. This is handy if you don't already have Linux,
but would like to pull a distribution down to your PC to install it.
- The pmirror script forks itself so that it can ftp files in the
background and download them in the foreground. This results in a
significant time savings over ftp'ing and downloading in serial.
- If interrupted, the process can be re-started without much
backtracking. Just run 'remote -c -p 1' on your PC and then start
again with 'remote -i'. Because the process works like a "Makefile",
the files that were downloaded up to the point of interruption will
not (normally) be downloaded again after when you re-start.
Where To Get "The Poor Man's Mirror Script"
See the pmirror*.lsm file for details. Archives of the scripts are
generally available on tsx-11.mit.edu mirrors, sunsite.unc.edu mirrors,
and from ftp.netcom.com. The UNIX archive will be named pmirror-*.tar.gz
and the DOS archive will be named pm-*.zip.
If you don't have ftp access of some kind, these scripts probably won't be
of much use to you. If you would like to have them anyway, send me a
request via e-mail, and I'll be glad to send them to you.
The LSM:
Begin3
Title: pmirror
Version: 1.6
Entered-date: 95-03-09
Description: Perl scripts for maintaining an up to date copy of any
archive directory structure available from a UNIX host
via anonymous ftp. Can be used over a modem with ZMODEM.
This is not the same as Lee McLoughlin <lmjm@doc.ic.ac.uk>'s
mirror-x.y.tar.gz package, which is more general purpose.
Keywords: Mirror Archive
Author: dsnyder@netcom.com (David C. Snyder)
Maintained-by: dsnyder@netcom.com (David C. Snyder)
Primary-site: tsx-11.mit.edu /pub/linux/BETA/pmirror
16k pmirror-1.6.tar.gz
20k pm-16.zip
Alternate-site: sunsite.unc.edu /pub/Linux/system/Network/file-transfer
16k pmirror-1.6.tar.gz
20k pm-16.zip
Original-site: ftp.netcom.com /pub/ds/dsnyder
16k pmirror-1.6.tar.gz
20k pm-16.zip
Platform:
Copying-policy:
End
History
About a year ago, I had heard and read much about Linux, but had never got
around to installing it to see what it was really about. After the 1.0
version of the kernel was released, I decided it was time. Back then,
CD's weren't as popular as they are now, and I didn't (and still don't)
have a CD-ROM drive. Since I had internet access through work, I decided
to pull the Slackware distribution down to a UNIX machine there and then
push it down to my PC using ZMODEM. I started the process manually, but
eventually broke down and hacked together five or so awk(1) and csh(1)
scripts to automate most of the process. Within a few days, I was up and
running Linux.
Since several of my friends were interested in Linux, and since I had some
free disk space, I thought it would be nice to keep the distribution on my
hard drive. A month or so down the road, Patrick Volkerding made massive
updates to Slackware, and my archive was out of date. At the same time, I
was starting to learn perl. I decided it might be fun to throw away my
awk(1) and csh(1) scripts and write a perl script that I could use to keep
my archive up to date. The scrip would work like a Makefile in the sense
that it would only download a file if it was new or if it had changed
since the last download.
The script had to actually be two scripts because two machines were
involved, the UNIX machine at my work and my Linux PC at home. The
script at home would take a recursive directory listing of my linux
archive and up-load that to the script at work. The script at work would
get a recursive directory listing of the Slackware distribution from an
ftp.cdrom.com mirror site and compare that listing with the listing from
home. It would create a list of files in my archive at home that were
obsolete and a list of files that needed to be added or updated from the
mirror site. Then it would ftp the files and ZMODEM them one by one down
to my PC. The script at home would make space for the new files and, as
each file finished downloading, it would move the file to its proper
location in my archive. Writing the script was quite an experience, and I
learned a lot about perl programming in the process.
I imagined that I might not be the only person interested in doing this
sort of thing, so I made my scripts available at sunsite.unc.edu and tsx-
11.mit.edu as well as in the ftp directory provided my Netcom, my current
internet service provider. Unfortunately, I unknowingly chose the same
name for my archive as Lee McLoughlin chose for his. Lee's scripts are
the ones that most ftp sites use to keep the archives that they "mirror"
from other sites in sync. I've seen his scripts and they are much fancier
than what I have cobbled together, so I had to come up with a new name.
The name I chose was pmirror, which stands for "Poor Man's Mirror". I
chose this name because my scripts are much smaller and easier to
understand, and they don't do nearly as much as the original.
-- David
dsnyder@netcom.com
--
Send submissions for comp.os.linux.announce to: linux-announce@news.ornl.gov
PLEASE remember Keywords: and a short description of the software.
