Shell script to rename files to YYYY-MM-DD/HHMMSS.EXT and if it already exists to YYYY-MM-DD/HHMMSS_1.EXT, YYYY-MM-DD/HHMMSS_2.EXT, YYYY-MM-DD/HHMMSS_3.EXT and so on

rename-to-date.sh

#!/bin/sh
# A script that renames files to
#  YYYY-MM-DD/HHMMSS.EXT
# and if it already exists to:
#  YYYY-MM-DD/HHMMSS_1.EXT
#  YYYY-MM-DD/HHMMSS_2.EXT
#  YYYY-MM-DD/HHMMSS_3.EXT
#  and so on
#
# I need this often and always forget where I put it.
# So this time I put it on the internet! :D
# May it be useful for you, too.
#  -- Stephan Beyer, 2013-11-19
#
# No warranty!
# Tested on a GNU system.

if [ -z "$*" ]
then
	echo "Usage: $0 filenames-to-rename [...]"
	exit 1
fi

for file in "$@"
do
	extension=$(basename "$file" | sed -ne 's/^\(.*\)\(\.[^\.]*\)$/\2/p')
	filename=$(stat -c %y "$file" | sed 's/\([^ ]*\) \([^\.]*\).*$/\1\/\2/' | tr -d :)
	if [ -z "$filename" ]
	then
		echo Something went wrong for "$file"
		continue
	fi
	mkdir -p $(dirname $filename)
	if [ -e "$filename$extension" ]
	then
		i=1
		while [ -e "$filename"_"$i$extension" ]
		do
			i=$((i+1))
		done
		newfile="$filename"_"$i$extension"
	else
		newfile="$filename$extension"
	fi
	mv -v "$file" $newfile
done