Env Pkg: Package your shell environment

env-pkg.sh

#!/bin/bash -
#
# env-pkg: Environment Packager -- super simple, see Usage below
#
# by: Charles Thayer <thayer@mediabridge.com>

cd $HOME
ENVPKG_RSH=${ENVPKG_RSH:-ssh}

ENVDIR=env-pkg
TMPDIR=/tmp/env-pkg-$USER
OLDSUFFIX="-"
SENTFILE="$HOME/.env-pkg-sent"
FILELIST="$HOME/.env-pkg-list"
WEBCACHE="$HOME/public_html/src/env.tar"
PORT=7034
prog=${0##*/}

usage() {		       
  sed -ne '/^Usage:/,/^For more/p' < $0
  exit $1
}

cmd=$1; shift
case $cmd in 
    -h) usage 0;;
    -init|-push|-pull|-t) 
        host=$1
        if [ -z $host ]; then usage 1; fi
        shift
        ;;
esac
pkgs=${*:-basic}

case $cmd in
    -o)				# stdout
        for p in $pkgs; do pkglist="$pkglist $ENVDIR/$p"; done
        tar cf - --ignore-failed-read $pkglist `cat $pkglist` | tee $WEBCACHE  # main output
        echo $host $pkgs >> $SENTFILE
        exit 0
        ;;

    -i)				# stdin
        if [ -d $TMPDIR ]; then rm -rf $TMPDIR; fi
        mkdir -p $TMPDIR
        cd $TMPDIR
        tar xvfp - > $FILELIST      # main listener
        for file in `cat $FILELIST`; do 
            if [ -f $HOME/$file ]; then
                if ! diff -q $HOME/$file $file > /dev/null; then 
                    echo Differing versions $file
		    if [ -f $HOME/$file -a $file -nt $HOME/$file ]; then
                        rm -f $HOME/$file$OLDSUFFIX
			mv $HOME/$file $HOME/$file$OLDSUFFIX
                        rm -f $HOME/$file
                        mv $file $HOME/$file
                    else 
                        echo Warning: $file is not newer, skipping >&2
                    fi
                fi
            else
                echo New version of $file
                mv $file $HOME/$file
            fi
        done
        exit 0
        ;;

  -init) exec $prog -o $pkgs | $ENVPKG_RSH $host "tar xvfp -";;
  -push) exec $prog -o $pkg | $ENVPKG_RSH $host "env-pkg -i";;
  -pull) exec $ENVPKG_RSH $host "env-pkg -o $pkgs" | $prog -i;;

  -t) exec $prog -o $* | ttcp -t -p$PORT $host;;
  -r) exec ttcp -r -p$PORT | $prog -i;;
  *) usage 1;;

esac
exit 0 

# README for env-pkg

Usage: env-pkg -o [pkglist..]
       env-pkg -i
       env-pkg -init host [pkglist..]
       env-pkg -push host [pkglist..]
       env-pkg -pull host [pkglist..]
       env-pkg -t host [pkglist..]
       env-pkg -r

    -i,-o  Read package from stdin or write to stdout.
    -init,-push,-pull  Use ssh (or \$ENVPKG_RSH) to send or get files.
    -t,-r  Use ttcp (or another network endpoint) to transmit or receive.

For more details see end of shell script

Super simple shell-script for maintaining user environment across many
machines.  A package is a file containing a list of files.  In
~/env-pkg create package files, starting with "basic" which is the
default when no package names are provided on the command line.

env-pkg will transfer files with tar as per the package list provided.
If the file already exists a backup version is created with a '-'
suffix, the target file is newer than source files (in which case the
source can be found in /tmp/env-pkg-$USER).  env-pkg is designed to be
short enough to cut and paste, but flexible enough to generally work
in hostile environments.

It keeps history files of what's been done when, and backups of 
replaced files.

Useful tricks:
  Don't have env-pkg yet:
    ssh master env-pkg -o | tar xvf -   

  Tip toe through firewall:
    lynx -dump http://master/~user/env.tar