convert_val

#!/bin/bash
#
#                         License
#
# Copyright (C) 2025  David Valin dvalin@redhat.com
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# Convert various time and memory units.

usage()
{
	echo "usage $1 <unit>"
	echo "-h --help --usage: This help message"
	echo "--value <value>: Value to be converted."
	echo "--from_unit <u>: Unit of value to be converted"
	echo "  Default K if --time_val is not specified, otherwise ns"
	echo "--time_val: Units being worked with are time vals"
	echo "--to_unit <u>: Unit to convert to."
	echo "  Default B if --time_val is not specified, otherwise s"
	echo "If just --from_unit is passed, program returns the unit value.  EG.  --from_unit K will return 1000B"
	echo "If --value and --from_unit, program returns the value in the base unit."
	echo "If --value, --from_unit and --to_unit is passed, then the program will convert <value><unit> to"
	echo "   the unit designated in --to_unit"
	echo ""
	echo "Example usage:"
	echo "$ $1 --from_unit M --value 1024 --to_unit G"
	echo "1G"
	echo "$ $1 --from_unit M --value 1024 --to_unit K"
	echo "1024000K"
	echo "$ $1 --from_unit Mi --value 1024 --to_unit Ki"
	echo "1048576Ki"
	echo "$ $1 --from_unit Mi --value 1024 --to_unit Gi"
	echo "1Gi"
	echo "$ $1 --from_unit Mi"
	echo "1000000B"
	echo "$ $1 --time_val --from_unit s --value 10 --to_unit ms"
	echo "10000ms"
	echo "$ $1 --time_val --from_unit s --value 60 --to_unit m"
	echo "1m"
	echo "$ $1 --time_val --from_unit s"
	echo "1000000000ns"
	exit 1
}

if [[ $1 == "" ]]; then
	usage $0
fi

NOARG_OPTS=(
	"help"
	"time_val"
	"usage"
)

ARG_OPTS=(
	"to_unit"
	"value"
	"from_unit"
)

opts=$(getopt \
	--longoptions "$(printf "%s," "${NOARG_OPTS[@]}")" \
	--longoptions "$(printf "%s:," "${ARG_OPTS[@]}")" \
	--name "$(basename "$0")" \
	--options "hc:" \
	-- "$@"
)

eval set --$opts

if [ $? -ne 0 ]; then
        exit 1
fi

#
# Set the unit defaults.
#

value=1
unit_val=""
cnv_to=""
rval=""
from_unit=""
to_unit=""
time_val=0

while [[ $# -gt 0 ]]; do
	case "$1" in
		-h | --usage | --help)
			usage $0
			exit 0
		;;
		--to_unit)
			to_unit=$2
			shift 2
		;;
		--time_val)
			time_val=1
			shift 1
		;;
		--value)
			value=$2
			shift 2
		;;
		--from_unit)
			from_unit=$2
			shift 2
		;;
		--)
			break
    		;;
		*)
			echo Unknown option $1
			usage $0
		;;
	esac
done

if [[ $to_unit == "" ]]; then
	if [ $time_val -eq 0 ]; then
		to_unit="B"
	else
		to_unit="ns"
	fi
fi
if [[ $from_unit == "" ]]; then
	if [ $time_val -eq 0 ]; then
		from_unit="K"
	else
		from_unit="s"
	fi
fi

cnvt_to_bytes()
{
	lunit=$1
	if [[ $lunit == "B" ]] || [[ $lunit == "b" ]]; then
		base_value=1
	else
		if [[ $lunit =~ [K,M,G,T] ]] && [[ $lunit != *"i"* ]]; then
			base_value=`numfmt --from=si 1${lunit}`
			if [[ $? -ne 0 ]]; then
				echo Error: Invalid unit $lunit
				exit 1
			fi
		else
			# 
			# Assumption is iec and convert to appropriate value
			#
			lunit=`echo "${lunit^^}" | sed "s/I//g"`
			base_value=`numfmt --from=iec 1${lunit}`
			if [[ $? -ne 0 ]]; then
				echo Error: Invalid unit $lunit
				exit 1
			fi
		fi
	fi
	echo $base_value
}

cnvt_unit_to_nsec()
{
	in_unit=$1

	if [[ $in_unit == "h"* ]]; then
		echo 3600000000000
	elif [[ $in_unit == "ms"* ]]; then
		echo 1000000
	elif [[ $in_unit == "m"* ]]; then
		echo 60000000000
	elif [[ $in_unit == "s"* ]]; then
		echo 1000000000
	elif [[ $in_unit == "u"* ]]; then
		echo 1000
	elif [[ $in_unit == "n"* ]]; then
		echo 1
	else
		echo Error: Invalid unit $in_unit
		exit 1
	fi
}

if [ $time_val -eq 0 ]; then
	to_base_unit=$(cnvt_to_bytes $from_unit)
	converting_to=$(cnvt_to_bytes $to_unit)
	cnv_value=`echo \(${value}*${to_base_unit}\)/$converting_to | bc`
	echo ${cnv_value}${to_unit}
else
	time_base_unit=$(cnvt_unit_to_nsec $from_unit)
	time_cnvt_to=$(cnvt_unit_to_nsec $to_unit)
	cnv_value=`echo \(${value}*${time_base_unit}\)/$time_cnvt_to | bc`
	echo ${cnv_value}${to_unit}
fi
exit 0