Shrink PDF file size with simple postscript conversion

shrink.sh

#!/bin/bash
LC_NUMERIC=C LC_COLLATE=C
start_time=`date +%s`

err ()
{
	echo $1
	exit $code
}

is_pdf()
{
	file=$1
	if [ $(head -c 4 "$file") = "%PDF" ]; then
		return 1
	fi
	return 0
}

nice_size()
{
	file=$1
	ls -lah $file | awk -F " " {'print $5'}
}

display_info()
{
	taken="$(expr `date +%s` - $start_time)"
	((sec=taken%60, taken/=60, min=taken%60, hrs=taken/60))
	timestamp=$(printf "%02d:%02d:%02d" $hrs $min $sec)
	echo "$1 t+$timestamp"
}

esacpe_fname()
{
	echo $(printf '%q' "$1")
}

orgfile=$2

if is_pdf "$orgfile"; then
    err "Not a pdf $orgfile"
fi

newfile="$orgfile.min"
psfile="$orgfile.ps"
pdf2ps "$orgfile" "$psfile"
ps2pdf "$psfile" "$newfile"

echo "Conversion done"

if is_pdf "$newfile"; then
    err "Invalid new pdf"
fi

orgsize="$(echo $(wc -c "$orgfile") | cut -f1 -d\ )"
newsize="$(echo $(wc -c "$newfile") | cut -f1 -d\ )"

if [ "$orgsize" -lt "$newsize" ]; then
	# original size lower new size
	# remove temp file
	rm "$newfile"
	# rm postscript file
	rm "$psfile"
	display_info "Clean up"
	err "Failed: New file bigger original"
else
	# remove original
	mv "$orgfile"  "org.$orgfile"
	# rename temp file
	mv "$newfile" "$orgfile"
	# rm postscript file
	rm "$psfile"
	reduced=$(printf %.2f $(echo "(1-$newsize/$orgsize)*100" | bc -l))
	display_info "Successfully shrinked about $reduced%"
	exit 0
fi

# TODO
#http://www.cyberciti.biz/tips/handling-filenames-with-spaces-in-bash.html