#!/bin/sh
#
# days_old
#
# Returns the number of days old for the specified file ($FILE), in a shell
# variable called:  DAYS_OLD
#
# Returns -1 if the specified file does not exist
#
# Note that this requires that this script be executed in the format of:
#    FILE=file.ext
#    . days_old
#
# <<<<<<<<<<<<<<< MODIFICATION HISTORY >>>>>>>>>>>>>>>
#   Date	Programmer	Description
# --------	---------------	-----------------------------------------------
# 02/20/97	Brian Lomasky	Original
# -----------------------------------------------------------------------------
#
#	Brian Lomasky does not implicitly or
#	explicitly implies any program or information is usable in any way.
#	All programs and information are released to the public domain in
#	an "AS-IS" condition.
#
afil=$FILE
if [ ! -r $afil ]
then
	echo "days_old Error:  $afil does not exist - Returning -1...\007"
	DAYS_OLD=-1; export DAYS_OLD
else
	today=`date`
	DAYS_OLD=`ls -l $afil | awk '
	BEGIN {
		dold = 0
		m = substr("'"$today"'",5,3)
		d = substr("'"$today"'",9,2)
		y = substr("'"$today"'",25,4)
	}
	{
		if (m == "Feb") dold = dold + 31
		if (m == "Mar") dold = dold + 59
		if (m == "Apr") dold = dold + 90
		if (m == "May") dold = dold + 120
		if (m == "Jun") dold = dold + 151
		if (m == "Jul") dold = dold + 181
		if (m == "Aug") dold = dold + 212
		if (m == "Sep") dold = dold + 243
		if (m == "Oct") dold = dold + 273
		if (m == "Nov") dold = dold + 304
		if (m == "Dec") dold = dold + 334
		if (int(y/4)*4 == y && dold > 31) dold = dold + 1
		if ($6 == "Feb") dold = dold - 31
		if ($6 == "Mar") dold = dold - 59
		if ($6 == "Apr") dold = dold - 90
		if ($6 == "May") dold = dold - 120
		if ($6 == "Jun") dold = dold - 151
		if ($6 == "Jul") dold = dold - 181
		if ($6 == "Aug") dold = dold - 212
		if ($6 == "Sep") dold = dold - 243
		if ($6 == "Oct") dold = dold - 273
		if ($6 == "Nov") dold = dold - 304
		if ($6 == "Dec") dold = dold - 334
		if (int($8/4)*$8 == $8 && ($6 == "Jan" || $6 == "Feb")) \
			dold = dold + 1
		dold = dold + d - $7
		if (dold < 0) dold = dold + int((y - $8) * 365.25)
		print dold
	} '`; export DAYS_OLD
fi