pledge(2) all programs

All programs except mshow have a very tight set of promises. mshow
has a broad set of promises and might be a good future candidate
to further restrict using unveil(2).

This patch is based on commit 0300a112 by Alex Holst (dated
2017-12-07), which was proposed in GH PR #79.

* pledged mpick, mflow and mdate so that now all programs are pledged
* removed some unneeded promises and added some missing promises
* move err.h include and OpenBSD ifdef into a new xpledge.h
* cleaned up code aligning and whitespace

Closes: #179 [via git-merge-pr]

1 files changed, 7 insertions, 1 deletions

diff --git a/mdate.c b/mdate.c
index fb95d7c..793f65e 100644
--- a/mdate.c
+++ b/mdate.c
@@ -1,11 +1,17 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "xpledge.h"
+
 int
 main()
 {
 	char buf[64];
-	time_t now = time(0);
+	time_t now;
+
+	xpledge("stdio", "");
+
+	now = time(0);
 
 	ssize_t l = strftime(buf, sizeof buf,
 	    "%a, %d %b %Y %T %z\n", localtime(&now));