#!/usr/bin/env sh

_pull=$(git pull)
_subs=$(git submodule update --recursive)

if [ "$_pull" == "Already up-to-date." ] && [ -z "$_subs" ]; then
	echo "Already up-to-date."
	exit 0
fi

./cleaninstall.sh
epm update

#!/usr/bin/env sh

_pull=$(git pull)
_subs=$(git submodule update --recursive)

if [ "$_pull" = "Already up-to-date." ] && [ -z "$_subs" ]; then
	echo "Already up-to-date."
	exit 0
fi

./cleaninstall.sh
epm update

Use POSIX string equality operator
Use POSIX string equality operator

shebang is looking for sh but is using bash's == operator to compare
strings. According to
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html
correct operator is =.
