filesize

#!/bin/bash
calc (){
	rv=$(echo "scale=2;$1" | bc)
	if echo "$rv" | grep -q .00$
	then
		echo "$rv" | cut -d"." -f1
	else 
		echo "$rv"
	fi
}

if [ $# = 0 ]
then
	echo "filesize: missing argument" && exit 1
fi

for file in "$@"
do
	if [ ! -f "$file" ]
	then
		echo "filesize: $file does not exist" && exit 1
	fi

	size=$(stat -c %s "$file")
	tb=1099511627776
	gb=1073741824
	mb=1048576
	kb=1024

	if [[ $size -ge $tb ]]
	then
		output="$(calc "$size/$tb") TB"
	elif [[ $size -ge $gb ]]
	then
		output="$(calc "$size/$gb") GB"
	elif [[ $size -ge $mb ]]
	then
		output="$(calc "$size/$mb") MB"
	elif [[ $size -ge $kb ]]
	then
		output="$(calc "$size/$kb") KB"
	else
		output="$size bytes"
	fi

	echo "$file: $output"
done