bin/gen-password: Add working utility

1 files changed, 73 insertions, 0 deletions

diff --git a/bin/gen-password b/bin/gen-password
new file mode 100755
index 0000000..b59213c
--- /dev/null
+++ b/bin/gen-password
@@ -0,0 +1,73 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  gen-password [LENGTH]
+		  gen-password -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -h, --help    show this message
+
+		  LENGTH        the length of the generated password
+				(default: 999)
+
+
+		Generate a random password, and emit it to STDOUT.
+
+
+		Examples:
+
+		  Create a file with a secret:
+
+		    $ gen-password > secret.txt
+
+
+		  Generate an absurdly long secret:
+
+		    $ gen-password 9999 > giant-secret.txt
+	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 $((OPTIND - 1))
+
+LENGTH="${1:-999}"
+
+tr -cd '[:alnum:]' < /dev/random |
+	fold -w "$LENGTH" |
+	head -n1