#!/bin/sh
# *** NOTE!!! ***
# This is one of three programs you will need to implement advisory quotas.
# There is also a related utility to actually pare down users' usage.
# The complete set consists of quota, usage, pareacct, and gawk (quota is
# written in gawk; it requires gawk to interpret/run it).
# The URLs to retrieve these are:
# ftp://ftp.armory.com/pub/admin/quota
# ftp://ftp.armory.com/pub/admin/usage
# ftp://ftp.armory.com/pub/admin/pareacct
# ftp://ftp.armory.com/pub/scobins/gawk (binary for SCO UNIX 3.2v5)

# @(#) usage.sh 2.1 97/04/19
# 94/03/03 john h. dubois iii (john@armory.com)
# 94/06/15 Generalized
# 94/07/10 Do only one 'mount' for all fs
# 94/07/11 Put date at start of file
# 95/07/02 Record inodes used
# 96/03/11 Use gawk to write date as epoch time so that quota can format it.
# 97/04/19 Make gawk test work right.

# Update usage file for use by quota.

# Usage: fs-device [mountdir fs-device ...]
MkDB() {
    quot=/usr/bin/quot
    Dir=
    case "$1" in
    /*) fs="$1";;
    *) fs="/dev/$1";;	# Add leading /dev if needed.
    esac
    shift
    if [ ! -b "$fs" ]; then
	echo "$0: $fs does not exist or is not a block device."
	return 1
    fi
    while [ $# -gt 0 ]; do
	if [ "$fs" = "$2" ]; then
	    Dir=$1
	    break
	fi
	shift; shift
    done
    if [ -z "$Dir" ]; then
	# Print this only if output is a terminal,
	# to avoid needless mail from cron.
	test -t && echo "$0: Filesystem $fs is not mounted."
	return 1
    fi
    file="$Dir/Usage"
    new=$file+
    echo "$Date" > $new
    # Discard error output unless quot fails,
    # because new quot whines about duplicate UIDs.
    ErrOut="`$quot $f "$fs" 2>&1 >> $new`" || echo "$ErrOut"
    # If mv fails, only print an error message if the new file still exists.
    # If it doesn't, mv failed because cron double-executed this job, creating
    # a race state; the other job moved it before this one could.
    mv "$new" "$file" 2>/dev/null || {
	if [ -f "$new" ]; then
	    echo "$0: Failed to move '$new' to '$file'"
	    l "$new" "$file"
	fi
    }
}

if [ "$1" = -h ]; then
    echo \
"$0: Build filesystem usage database for the 'quota' program.
Usage: $0 [-h] filesystem-device ...
For each filesystem device named, a usage database is written into a
file named Usage in the directory the filesystem is mounted on.
This command is typically run from root's crontab at regular intervals.
Example: $0 /dev/u /dev/v"
    exit 0
fi

if [ $# -eq 0 ]; then
    echo "$0: No device names given.  Use -h for help."
    exit 1
fi

Filesystems="$*"
OIFS=$IFS
IFS='
'
set -- `/etc/mount`
IFS=$OIFS
f=-f	# Record inodes used also; comment this out if inode quotas not used

PATH=$PATH:/usr/local/bin
Date=`(gawk '
BEGIN {
    printf "%s (%s)\n",systime(),strftime("%a %b %d %H:%M")
}
') 2>/dev/null` || Date=`date '+%a %b %d %H:%M'`
for fs
do
    set -- $fs
    # This needs to be changed if using xenix 'mount' cmd
    DevList="$DevList $1 $3"
done

umask 022	# let everyone read the usage file
for fs in $Filesystems
do
    MkDB "$fs" $DevList
done