From bb9f8584c312b5bc641430adfeda68b80c58e5d5 Mon Sep 17 00:00:00 2001
From: Graham Lyons <graham@grahamlyons.com>
Date: Fri, 10 Mar 2017 13:20:43 +0000
Subject: [PATCH] Use the `rm` command with `-P` as a shred fallback (#179)

* Use the `rm` command with `-P` as a shred fallback

The newer versions of OSX (Sierra) have neither `shred` nor `srm`.
They do have `rm` with the `-P` option, so we can fall back to that
before resorting to plain old `rm`.

* Add double-quotes and braces to the shell variable.

We should treat the variable as a string, and we should also be safe
when interpolating it.
---
 bin/_blackbox_common.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/bin/_blackbox_common.sh b/bin/_blackbox_common.sh
index 46447bf..6ff377a 100755
--- a/bin/_blackbox_common.sh
+++ b/bin/_blackbox_common.sh
@@ -312,6 +312,9 @@ function shred_file() {
     #NOTE: srm by default uses 35-pass Gutmann algorithm
     CMD=srm
     OPT=-f
+  elif _F=$(mktemp); rm -P "${_F}" >/dev/null 2>/dev/null ; then
+    CMD=rm
+    OPT=-Pf
   else
     echo "shred_file: WARNING: No secure deletion utility (shred or srm) present; using insecure rm"
     CMD=rm