Deal with those needless carriage returns (CR) in text files from/for coworkers/friends on Windows

fixcr.sh

#!/usr/bin/env bash

readonly CR=$'\r'

# Add CR to given stream
add_cr()
{
	while read -r
	do
		echo "$REPLY"$CR
	done
}

# Remove CR from given stream
rm_cr()
{
	while read -r
	do
		echo "${REPLY%$CR}"
	done
}

# Returns true if the first line ends with a CR
has_cr()
{
	read -r && [[ $REPLY == *$CR ]]
}

# Fix CR for given files
#
# @param ... - files to process
fix_cr()
{
	local F T=".${0##*/}-$$" LOCK=${LOCK:-auto}

	while [ -e "$T" ]
	do
		T="$T-$$"
	done

	for F
	do
		[ -r "$F" ] || {
			echo "error: cannot read $F" >&2
			continue
		}

		local A=add_cr
		if has_cr < "$F"
		then
			[ "$LOCK" == 'add' ] && continue
			A=rm_cr
		else
			[ "$LOCK" == 'rm' ] && continue
		fi

		"$A" < "$F" > "$T" && mv "$T" "$F"
	done
}

if [ "${BASH_SOURCE[0]}" == "$0" ] && (( $# > 0 ))
then
	fix_cr "$@"
fi