genpasswd: init

1 files changed, 56 insertions, 0 deletions

diff --git a/pkgs/shell/genpasswd b/pkgs/shell/genpasswd
new file mode 100755
index 0000000..a6d96aa
--- /dev/null
+++ b/pkgs/shell/genpasswd
@@ -0,0 +1,56 @@
+#! /bin/sh
+#!buildShellBin path=coreutils
+#
+# NAME
+#       genpasswd - generate a password
+#
+# SYNOPSIS
+#       genpasswd [OPTION]...
+#
+# DESCRIPTION
+#       Produce a random string of a given length and alphabet to standard
+#       output.
+#
+#       --length=number (default: 71)
+#         Specify the number of bytes to produce.
+#
+#       --alphabet=string (default: -+.,=/A-Za-z0-9_)
+#         Specify the list of characters that can be produced.
+#         The string gets interpreted by tr and may contain single-character
+#         collating elements. See tr(1) for details.
+#
+#       --newline=bool (default: true)
+#         Specify whether a newline should be appended to the output.
+#
+
+set -efu
+
+alphabet=-+.,=/A-Za-z0-9_
+length=71
+newline=true
+
+while test $# -gt 0; do
+  case $1 in
+    --alphabet=*)
+      alphabet=${1//--alphabet=}
+      shift
+      ;;
+    --length=*)
+      length=${1//--length=}
+      shift
+      ;;
+    --newline=true|--newline=false)
+      newline=${1//--newline=}
+      shift
+      ;;
+    *)
+      echo "$0: bad argument: $1" >&2
+      exit 1
+  esac
+done
+
+tr -dc -- "$alphabet" < /dev/urandom | dd status=none bs="$length" count=1
+
+case $newline in true)
+  echo
+esac