#!/bin/sh -u
#  $0 [ filenames... ]
# Show how each file name differs from its sorted version.
# -IAN! idallen@ncf.ca

export PATH=/bin:/usr/bin
umask 022

# Loop for each command line argument.
#
for file do
	echo "Processing: $file"

	# Validate the arguments.
	#
	if [ ! -r "$file" ]; then
		echo 1>&2 "$0: '$file' is not readable"
		exit 1
	fi
	if [ ! -f "$file" ]; then
		echo 1>&2 "$0: '$file' is not a file"
		exit 1
	fi

	# Sort the file into a temporary file.
	# Count the differences (remove the leading blanks from the number).
	# Print the message.
	#
	sorted=/tmp/sorted$$
	sort "$file" >"$sorted" || exit $?
	count=$(diff "$file" "$sorted" | wc -l | tr -d " ")
	echo "The file differs from its sorted version by $count lines."
	rm "$sorted"
done