bin/prompt: Add initial working version

1 files changed, 75 insertions, 0 deletions

diff --git a/bin/prompt b/bin/prompt
new file mode 100755
index 0000000..a191238
--- /dev/null
+++ b/bin/prompt
@@ -0,0 +1,75 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  prompt STRING|-
+		  prompt -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -h, --help    show this message
+
+		  STRING        the text to be displayed in the prompt
+
+
+		Display a prompt and return a value corresponding to the
+		response.
+	EOF
+}
+
+assert_arg() {
+	if [ -z "$1" ]; then
+		printf 'Missing %s.\n\n' "$2" >&2
+		usage >&2
+		exit 2
+	fi
+}
+
+
+for flag in "$@"; 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 $((OPTIND - 1))
+
+STRING="${1:-}"
+assert_arg "$STRING" 'STRING'
+
+printf '%s' "$STRING"
+printf ' [Y/n]: '
+read -r yesno
+if [ "$yesno" != 'n' ] && [ "$yesno" != 'N' ]; then
+	exit 0
+else
+	exit 1
+fi