#! /bin/sh

# Question 10:

# Modify your answer to question 9 so that your program will take a list
# of names in the form computer:destination on the command line, and
# will make each location contain a copy of ~/public_html on the local
# machine.  For example, if the program is called rsync-to-websites,
# then if it is executed like this:

# $ rsync-to-websites ictlab:/var/www/html/mystuff \
# 172.19.64.50:/var/www/backup 172.19.64.51:/var/www/html

# and if the local machine has a file /public html/important.html, then on the
# computer ictlab, a file /var/www/html/mystuff/important.html will be created,
# and on the computer 172.19.64.50, the file /var/www/backup/important.html
# will be created, and on the computer 172.19.64.51, the file /var/www/html/
# important.html will be created.

prog=$(basename $0)

usage() {
    cat <<EOF
Usage: $prog remote1:path1 remote2:path2 ...
where remote1, remote2 are the IP addresses or hostnames of remote
computers.  This program will transfer ~/public_html to the directory
~/public_html-backup on the remote computer.
EOF
    exit 1
}

[ $# -ge 1 ] || usage;

uid_num=$(id -u)

lockfile="/tmp/${prog}.lock"
[ "$uid_num" -eq 0 ] && lockfile=/var/lock/subsys/${prog}.lock

signal_handler() {
    echo "received a signal; terminating"
    rm -f $lockfile
    exit 1
}

[ -r ~/.keychain/${HOSTNAME}-sh ] || {
    echo "No keychain filename; exiting";
    exit 1
}

if [ -e "$lockfile" ]
then
    echo "lockfile exists"
    exit 1
else
    trap signal_handler INT TERM HUP QUIT
    touch $lockfile
    [ -e $lockfile ] || { echo "$prog: cannot create $lockfile"; exit 1; }
fi

source ~/.keychain/${HOSTNAME}-sh

for remote
do
    echo $remote | grep -q ':' || { echo "$remote has no colon"; continue; }
    rsync -avz -e ssh ~/public_html/ ${remote}
done

rm -f $lockfile