#!/bin/ksh
# @(#) mvuser.ksh 1.0 95/10/26
# 95/10/26 john h. dubois iii (john@armory.com)

name=${0##*/}

Usage="Usage:
$name [-htn] [-d<parent-dir>] <newdir> <user> ..."
Tell=false
Symlink=true
parentDir=

while getopts :htd:n opt; do
    case $opt in
    h)
	echo \
"$name: Move a user's home directory to a different parent directory.
$Usage
<newdir> is the name of a directory (typically the mount point of a user
filesystem) that user accounts are put in.  For safety, <newdir> is required to
be an absolute path (one beginning with /).  The home directory of each named
user is moved so that it resides under <newdir>.  The last component of the
user's home directory name is maintained.  This utility does NOT make any
changes to the password database; instead, symbolic links are created where
the old home directories were, pointing to the new home directories.
Example:
$name /v pax midnight
If pax's home directory was /u/pax and midnight's home directory was /u/jon,
this would copy /u/pax to /v/pax and /u/jon to /v/jon, remove the original home
directories, and create symbolic links pointing from /u/pax to /v/pax and from
/u/jon to /v/jon.
User's home directories should be moved at a time when the user is not logged
in, preferably in single-user (system maintenance) mode.
Options:
-d<parent-dir>: Expect users' current home directories to be
    <parent-dir>/username, instead of using the password database to find
    users' home directories.
-h: Print this help.
-n: Do not create a symbolic link pointing from users' old home directories
    to their new home directories.
-t: Tell what would be done without doing it."
	exit 0
	;;
    d)
	parentDir=$OPTARG
	if [[ "$parentDir" != /* ]]; then
	    print -u2 \
"$name: Directory given with -d must be given as an absolute path.  Aborting."
	    exit 1
	fi

	;;
    t)
	Tell=true
	;;
    n)
	Symlink=false
	;;
    +?)
	print -u2 "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :)
        print -r -u2 -- \
        "$name: Option '$OPTARG' requires a value.  Use -h for help."
        exit 1
        ;;
    ?) 
	print -u2 "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done
 
# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

# Must have 2 or more args.
if [ $# -lt 2 ]; then
    print -u2 "$Usage\nUse -h for help."
    exit
fi

set -e	# for extra safety
newdir=$1
shift

if [[ "$newdir" != /* ]]; then
    print -u2 \
    "$name: New directory must be given as an absolute path.  Aborting."
    exit 1
fi

if [ ! -d "$newdir" ]; then
    print -u2 "$name: $newdir is not a directory.  Aborting."
    exit 1
fi

typeset -i i=0

# Get list of old home dirs
OIFS="$IFS"
IFS=:
for user; do
    egrep "^$user:" /etc/passwd | read us pa ui gi na home shell || {
	print -u2 "$name: $user: No such user.  Aborting."
	exit 1
    }
    [ -n "$parentDir" ] && home="$parentDir/$user"
    # Check for as much as we can before moving any users
    if [ ! -d "$home" ]; then
	print -u2 \
"$name: Home directory for $user ($home) does not exist or
is not a directory.  Aborting."
	exit 1
    fi
    if [ "$home" -ef / ]; then
	print -u2 \
	"$name: Home directory for $user is the root directory! Aborting."
	exit 1
    fi
    homeName=${home##*/}
    newHome=$newdir/$homeName
    if [ -a "$newHome" ]; then
	print -u2 \
    "$name: New home directory for $user ($newHome) already exists.  Aborting."
	exit 1
    fi
    oldHomes[i]=$home
    let i+=1
done
IFS="$OIFS"

for home in "${oldHomes[@]}"; do
    homeName=${home##*/}
    newHome=$newdir/$homeName
    if $Tell; then
	print "Would move $home to $newHome"
	continue
    fi
    mvdir "$home" "$newHome" 2>/dev/null || {
	oldBase=${home%/*}
	cd $oldBase
	print "Copying $home to $newHome..."
	find "$homeName" -print | cpio -pldmu $newdir || {
	    print -u2 "$name: Copy of $home to $newHome failed.  Aborting."
	    exit 1
	}
	print "Removing $home..."
	rm -r $home || {
	    print -u2 "$name: Removal of $home failed.  Aborting."
	    exit 1
	}
    }
    if $Symlink; then
	print "Creating symlink pointing from $home to $newHome..."
	ln -s $newHome $home || {
	    print -u2 "$name: symlink of $newHome to $home failed.  Aborting."
	    exit 1
	}
    fi
    print "Completed move of $home to $newHome"
done