#!/bin/sh
#
# Copyright (c) 2002, 2003 Michael Telahun Makonnen. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
#	Email: Mike Makonnen <mtm@FreeBSD.Org>
#
# $FreeBSD: stable/11/usr.sbin/adduser/rmuser.sh 181006 2008-07-30 18:37:21Z jhb $
#

setglobal ATJOBDIR = '"/var/at/jobs'"
setglobal CRONJOBDIR = '"/var/cron/tabs'"
setglobal MAILSPOOL = '"/var/mail'"
setglobal SIGKILL = '"-KILL'"
setglobal TEMPDIRS = '"/tmp /var/tmp'"
setglobal THISCMD = $[/usr/bin/basename $0]
setglobal PWCMD = $(PWCMD:-/usr/sbin/pw)

# err msg
#	Display $msg on stderr.
#
proc err {
	echo 1>&2 $(THISCMD): $ifsjoin(Argv)!1 > !2 ${THISCMD}: $*
}

# verbose
#	Returns 0 if verbose mode is set, 1 if it is not.
#
proc verbose {
	test -n $vflag && return 0 || return 1
}

# rm_files login
#	Removes files or empty directories belonging to $login from various
#	temporary directories.
#
proc rm_files {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	setglobal totalcount = '0'
	for _dir in [$(TEMPDIRS)]  {
		setglobal filecount = '0'
		if test ! -d $_dir {
			err "$_dir is not a valid directory."
			continue
		}
		verbose && echo -n "Removing files owned by ($login) in $_dir:"
		setglobal filecount = $[find 2>/dev/null $_dir -user $login -delete -print!2 >/dev/null "$_dir" -user "$login" -delete -print |
		    wc -l | sed 's/ *//]
		verbose && echo " $filecount removed."
		setglobal totalcount = $shExpr('$totalcount + $filecount')
	}
	! verbose && test $totalcount -ne 0 && echo -n " files($totalcount)"
}

# rm_mail login
#	Removes unix mail and pop daemon files belonging to the user
#	specified in the $login argument.
#
proc rm_mail {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	verbose && echo -n "Removing mail spool(s) for ($login):"
	if test -f $(MAILSPOOL)/$login {
		verbose && echo -n " $(MAILSPOOL)/$login" ||
		    echo -n " mailspool"
		rm $(MAILSPOOL)/$login
	}
	if test -f $(MAILSPOOL)/.$(login).pop {
		verbose && echo -n " $(MAILSPOOL)/.$(login).pop" ||
		    echo -n " pop3"
		rm $(MAILSPOOL)/.$(login).pop
	}
	verbose && echo '.'
}

# kill_procs login
#	Send a SIGKILL to all processes owned by $login.
#
proc kill_procs {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	verbose && echo -n "Terminating all processes owned by ($login):"
	setglobal killcount = '0'
	setglobal proclist = $[ps 2>/dev/null -U $login!2 >/dev/null -U $login | grep -v '^\ *PID' | awk '{print $1}]
	for _pid in [$proclist]  {
		kill 2>/dev/null $(SIGKILL) $_pid!2 >/dev/null ${SIGKILL} $_pid
		setglobal killcount = $shExpr('$killcount + 1')
	}
	verbose && echo " $(SIGKILL) signal sent to $killcount processes."
	! verbose && test $killcount -ne 0 && echo -n " processes($(killcount))"
}

# rm_at_jobs login
#	Remove at (1) jobs belonging to $login.
#
proc rm_at_jobs {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	setglobal atjoblist = $[find 2>/dev/null $(ATJOBDIR) -maxdepth 1 -user $login -print!2 >/dev/null]
	setglobal jobcount = '0'
	verbose && echo -n "Removing at(1) jobs owned by ($login):"
	for _atjob in [$atjoblist]  {
		rm -f $_atjob
		setglobal jobcount = $shExpr('$jobcount + 1')
	}
	verbose && echo " $jobcount removed."
	! verbose && test $jobcount -ne 0 && echo -n " at($jobcount)"
}

# rm_crontab login
#	Removes crontab file belonging to user $login.
#
proc rm_crontab {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	verbose && echo -n "Removing crontab for ($login):"
	if test -f $(CRONJOBDIR)/$login {
		verbose && echo -n " $(CRONJOBDIR)/$login" || echo -n " crontab"
		rm -f $(CRONJOBDIR)/$login
	}
	verbose && echo '.'
}

# rm_ipc login
#	Remove all IPC mechanisms which are owned by $login.
#
proc rm_ipc {
	verbose && echo -n "Removing IPC mechanisms"
	for i in [s m q] {
		ipcs -$i |
		awk -v i=$i -v login=$1 '$1 == i && $5 == login { print $2 }' |
		xargs -n 1 ipcrm -$i
	}
	verbose && echo '.'
}

# rm_user login
#	Remove user $login from the system. This subroutine makes use
#	of the pw(8) command to remove a user from the system. The pw(8)
#	command will remove the specified user from the user database
#	and group file and remove any crontabs. His home
#	directory will be removed if it is owned by him and contains no 
#	files or subdirectories owned by other users. Mail spool files will
#	also be removed.
#
proc rm_user {
	# The argument is required
	test -n $1 && setglobal login = $1 || return

	verbose && echo -n "Removing user ($login)"
	test -n $pw_rswitch && do {
		verbose && echo -n " (including home directory)"
		! verbose && echo -n " home"
	}
	! verbose && echo -n " passwd"
	verbose && echo -n " from the system:"
	$(PWCMD) userdel -n $login $pw_rswitch
	verbose && echo ' Done.'
}

# prompt_yesno msg
#	Prompts the user with a $msg. The answer is expected to be
#	yes, no, or some variation thereof. This subroutine returns 0
#	if the answer was yes, 1 if it was not.
#
proc prompt_yesno {
	# The argument is required
	test -n $1 && setglobal msg = $1 || return

        while : {
                echo -n $msg
                read _ans
                match $_ans {
                with [Nn][Oo]|[Nn]
			return 1
                        
                with [Yy][Ee][Ss]|[Yy][Ee]|[Yy]
                        return 0
                        
                with *
                        
                }
	}
}

# show_usage
#	(no arguments)
#	Display usage message.
#
proc show_usage {
	echo "usage: $(THISCMD) [-yv] [-f file] [user ...]"
	echo "       if the -y switch is used, either the -f switch or"
	echo "       one or more user names must be given"
}

#### END SUBROUTINE DEFENITION ####

setglobal ffile = ''
setglobal fflag = ''
setglobal procowner = ''
setglobal pw_rswitch = ''
setglobal userlist = ''
setglobal yflag = ''
setglobal vflag = ''

setglobal procowner = $[/usr/bin/id -u]
if test $procowner != "0" {
	err 'you must be root (0) to use this utility.'
	exit 1
}

setglobal args = $[getopt 2>/dev/null yvf: $ifsjoin(Argv)!2 >/dev/null]
if test "$Status" != "0" {
	show_usage
	exit 1
}
set -- $argsfor _switch in @Argv {
	match $_switch {
	with -y
		setglobal yflag = '1'
		shift
		
	with -v
		setglobal vflag = '1'
		shift
		
	with -f
		setglobal fflag = '1'
		setglobal ffile = $2
		shift; shift
		
	with --
		shift
		break
		
	}
}

# Get user names from a file if the -f switch was used. Otherwise,
# get them from the commandline arguments. If we're getting it
# from a file, the file must be owned by and writable only by root.
#
if test $fflag {
	setglobal _insecure = $[find $ffile ! -user 0 -or -perm +0022]
	if test -n $_insecure {
		err "file ($ffile) must be owned by and writeable only by root."
		exit 1
	}
	if test -r $ffile {
		setglobal userlist = $[cat $ffile | while read _user _junk {
			match $_user {
			with \#*|''
				
			with *
				echo -n "$userlist $_user"
				
			}
		}]
	}
} else {
	while test $1 {
		setglobal userlist = ""$userlist $1""
		shift
	}
}

# If the -y or -f switch has been used and the list of users to remove
# is empty it is a fatal error. Otherwise, prompt the user for a list
# of one or more user names.
#
if test ! $userlist {
	if test $fflag {
		err "($ffile) does not exist or does not contain any user names."
		exit 1
	} elif test $yflag {
		show_usage
		exit 1
	} else {
		echo -n "Please enter one or more usernames: "
		read userlist
	}
}

setglobal _user = ''
setglobal _uid = ''
for _user in [$userlist]  {
	# Make sure the name exists in the passwd database and that it
	# does not have a uid of 0
	#
	setglobal userrec = $[pw 2>/dev/null usershow -n $_user!2 >/dev/null]
	if test "$Status" != "0" {
		err "user ($_user) does not exist in the password database."
		continue
	}
	setglobal _uid = $[echo $userrec | awk -F: '{print $3}]
	if test $_uid = "0" {
		err "user ($_user) has uid 0. You may not remove this user."
		continue
	}

	# If the -y switch was not used ask for confirmation to remove the
	# user and home directory.
	#
	if test -z $yflag {
		echo "Matching password entry:"
		echo
		echo $userrec
		echo
		if ! prompt_yesno "Is this the entry you wish to remove? "  {
			continue
		}
		setglobal _homedir = $[echo $userrec | awk -F: '{print $9}]
		if prompt_yesno "Remove user's home directory ($_homedir)? " {
			setglobal pw_rswitch = '"-r'"
		}
	} else {
		setglobal pw_rswitch = '"-r'"
	}

	# Disable any further attempts to log into this account
	$(PWCMD) 2>/dev/null lock $_user!2 >/dev/null lock $_user

	# Remove crontab, mail spool, etc. Then obliterate the user from
	# the passwd and group database.
	#
	! verbose && echo -n "Removing user ($_user):"
	rm_crontab $_user
	rm_at_jobs $_user
	rm_ipc $_user
	kill_procs $_user
	rm_files $_user
	rm_mail $_user
	rm_user $_user
	! verbose && echo "."
}