1 files changed, 84 insertions, 0 deletions
diff --git a/bin/max b/bin/max
new file mode 100755
index 0000000..ae38983
--- /dev/null
+++ b/bin/max
@@ -0,0 +1,84 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  max NUMBER...
+		  max -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -h, --help    show this message
+
+		Get the maximum number from the given values.
+
+
+		Examples:
+
+		  Get the maximum number from a list:
+
+		    $ min 5 3 9 9 4
+		    9
+
+		  Get the maximum number when negative numbers are given
+
+		    $ max -- -3 -5
+		    -3
+
+		  Get the maximum number given a single number
+
+		    $ max 8
+		    8
+
+		  The maximum default number:
+
+		    $ max
+		    0
+	EOF
+}
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'h' flag; do
+	case "$flag" in
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+if [ -z "${1:-}" ]; then
+	echo 0
+	exit
+fi
+
+N="$1"
+for n in "$@"; do
+	N=$((N > n ? N : n))
+done
+echo "$N"