From d8b74be608737d09e71ca55ba0b62f949585343c Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Thu, 26 Apr 2012 18:22:24 +1000
Subject: [PATCH] Read a maximum output level from the env.

Importantly this does not change whether log parameters are evaluated,
it simply prevents output to the log stream; ie, it is purely aethetic.
---
 log.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/log.cpp b/log.cpp
index 6a6b77b0..73a8d5c5 100644
--- a/log.cpp
+++ b/log.cpp
@@ -93,8 +93,26 @@ util::log (level_t l, const std::string &format)
     { detail::log (l, boost::format (format)); }
 
 
+static level_t
+log_level (void) {
+    const char *env = getenv ("LOG_LEVEL");
+    if (!env)
+        return DEFAULT;
+
+    try {
+        return string_to_level (env);
+    } catch (...) {
+        return DEFAULT;
+    }
+}
+
+
 void
 util::detail::log (level_t level, boost::format &&format) {
+    static const level_t LOG_LEVEL = log_level ();
+    if (level > LOG_LEVEL)
+        return;
+
     static const boost::format LEVEL_FORMAT ("%s [%s] ");
     
     char time_string[strlen("YYYY-mm-dd HHMMh") + 1];