Added sprintf-like %s support

tj · tj · commit cc80e06b8351 · 2011-05-23T11:28:07.000-07:00
diff --git a/Readme.md b/Readme.md
@@ -30,6 +30,10 @@ Instead of the log level constants, you may also supply a string:
     var Log = require('log')
       , log = new Log('warning');
 
+ We can also use `%s` much like `console.log()` to pass arguments:
+ 
+     log.error('oh no, failed to send mail to %s.', user.email);
+
 ## Reader
 
  To stream a log, simply pass a readable stream instead of a writable:
diff --git a/examples/file.log b/examples/file.log
@@ -6,3 +6,11 @@
 [Sun, 26 Sep 2010 01:26:14 GMT] CRITICAL a critical message
 [Sun, 26 Sep 2010 01:26:14 GMT] ALERT a alert message
 [Sun, 26 Sep 2010 01:26:14 GMT] EMERGENCY a emergency message
+[Thu, 03 Feb 2011 04:54:39 GMT] DEBUG a debug message
+[Thu, 03 Feb 2011 04:54:39 GMT] INFO a info message
+[Thu, 03 Feb 2011 04:54:39 GMT] NOTICE a notice message
+[Thu, 03 Feb 2011 04:54:39 GMT] WARNING a warning message
+[Thu, 03 Feb 2011 04:54:39 GMT] ERROR a error message
+[Thu, 03 Feb 2011 04:54:39 GMT] CRITICAL a critical message
+[Thu, 03 Feb 2011 04:54:39 GMT] ALERT a alert message
+[Thu, 03 Feb 2011 04:54:39 GMT] EMERGENCY a emergency message
diff --git a/examples/stdout.js b/examples/stdout.js
@@ -13,4 +13,5 @@ log.warning('a warning message');
 log.error('a error message');
 log.critical('a critical message');
 log.alert('a alert message');
-log.emergency('a emergency message');
+log.emergency('a emergency %s', 'message');
+log.emergency('a really %s emergency %s', 'bad', 'message');
diff --git a/lib/log.js b/lib/log.js
@@ -139,12 +139,16 @@ Log.prototype = {
    * Log output message.
    *
    * @param  {String} levelStr
-   * @param  {String} msg
+   * @param  {Array} args
    * @api private
    */
 
-  log: function(levelStr, msg) {
+  log: function(levelStr, args) {
     if (exports[levelStr] <= this.level) {
+      var i = 1;
+      var msg = args[0].replace(/%s/g, function(){
+        return args[i++];
+      });
       this.stream.write(
           '[' + new Date().toUTCString() + ']'
         + ' ' + levelStr
@@ -162,7 +166,7 @@ Log.prototype = {
    */
 
   emergency: function(msg){
-    this.log('EMERGENCY', msg);
+    this.log('EMERGENCY', arguments);
   },
 
   /**
@@ -173,7 +177,7 @@ Log.prototype = {
    */
 
   alert: function(msg){
-    this.log('ALERT', msg);
+    this.log('ALERT', arguments);
   },
 
   /**
@@ -184,7 +188,7 @@ Log.prototype = {
    */
 
   critical: function(msg){
-    this.log('CRITICAL', msg);
+    this.log('CRITICAL', arguments);
   },
 
   /**
@@ -195,7 +199,7 @@ Log.prototype = {
    */
 
   error: function(msg){
-    this.log('ERROR', msg);
+    this.log('ERROR', arguments);
   },
 
   /**
@@ -206,7 +210,7 @@ Log.prototype = {
    */
 
   warning: function(msg){
-    this.log('WARNING', msg);
+    this.log('WARNING', arguments);
   },
 
   /**
@@ -217,7 +221,7 @@ Log.prototype = {
    */
 
   notice: function(msg){
-    this.log('NOTICE', msg);
+    this.log('NOTICE', arguments);
   },
 
   /**
@@ -228,7 +232,7 @@ Log.prototype = {
    */ 
 
   info: function(msg){
-    this.log('INFO', msg);
+    this.log('INFO', arguments);
   },
 
   /**
@@ -239,7 +243,7 @@ Log.prototype = {
    */
 
   debug: function(msg){
-    this.log('DEBUG', msg);
+    this.log('DEBUG', arguments);
   }
 };
 
