Add "custom" output for CLI

bin/bunyan

@@ -25,6 +25,7 @@ var child_process = require('child_process'),
     exec = child_process.exec,
     execFile = child_process.execFile;
 var assert = require('assert');
+var _ = null;
 
 var nodeSpawnSupportsStdio = (
     Number(process.version.split('.')[0]) >= 0 ||
@@ -44,14 +45,16 @@ var OM_INSPECT = 3;
 var OM_SIMPLE = 4;
 var OM_SHORT = 5;
 var OM_BUNYAN = 6;
+var OM_CUSTOM = 7;
 var OM_FROM_NAME = {
     'long': OM_LONG,
     'paul': OM_LONG,  /* backward compat */
     'json': OM_JSON,
     'inspect': OM_INSPECT,
     'simple': OM_SIMPLE,
     'short': OM_SHORT,
-    'bunyan': OM_BUNYAN
+    'bunyan': OM_BUNYAN,
+    'custom': OM_CUSTOM
 };
 
 
@@ -225,6 +228,14 @@ function printHelp() {
     p('                  bunyan: 0 indented JSON, bunyan\'s native format');
     p('                  inspect: node.js `util.inspect` output');
     p('                  short: like "long", but more concise');
+    p('                  custom: use custom template defined with --template');
+    p('  -t, --template TEMPLATE');
+    p('                Custom template (you need to set -o custom)');
+    p('                Let you define your own templates, using mustache-like syntax.');
+    p('                Keys from the current object will be the template free variable.');
+    p('                You can put arbitrary code between {{ }}.');
+    p('                Use _cS to start a color, and _cE to stop a color.');
+    p('                Example: {{ _cS(\'grey\') }}{{ req.username }}{{ _cE(\'grey\') }}');
     p('  -j            shortcut for `-o json`');
     p('  -0            shortcut for `-o bunyan`');
     p('');
@@ -484,6 +495,20 @@ function parseArgv(argv) {
                     throw new Error('unknown output mode: "'+name+'"');
                 }
                 break;
+            case '-t':
+            case '--template':
+                try {
+                    _ = require('underscore');
+                } catch(e) {
+                    throw new Error("you need to install 'underscore' to use the custom template.");
+                }
+                // Who want ERB? (not me)
+                // Let's go for mustache style parsing!
+                _.templateSettings = {
+                  interpolate: /\{\{(.+?)\}\}/g
+                };
+                parsed.template = _.template(args.shift());
+                break;
             case '-j': // output with JSON.stringify
                 parsed.outputMode = OM_JSON;
                 break;
@@ -618,17 +643,33 @@ function stylizeWithColor(str, color) {
         return '';
     var codes = colors[color];
     if (codes) {
-        return '\033[' + codes[0] + 'm' + str +
-                     '\033[' + codes[1] + 'm';
+        return stylizeWithColor.start(color) + str + stylizeWithColor.end(color);
     } else {
         return str;
     }
 }
 
+stylizeWithColor.start = function(color) {
+    var codes = colors[color];
+    if (codes) {
+        return '\033[' + codes[0] + 'm';
+    }
+};
+
+stylizeWithColor.end = function(color) {
+    var codes = colors[color];
+    if (codes) {
+        return '\033[' + codes[1] + 'm';
+    }
+};
+
+
 function stylizeWithoutColor(str, color) {
     return str;
 }
 
+stylizeWithoutColor.start = stylizeWithoutColor.end = function() {};
+
 
 /**
  * Is this a valid Bunyan log record.
@@ -1018,6 +1059,29 @@ function emitRecord(rec, line, opts, stylize) {
             upperNameFromLevel[rec.level] || 'LVL' + rec.level,
             rec.msg));
         break;
+
+    case OM_CUSTOM:
+        if (!isValidRecord(rec)) {
+            return emit(line + '\n');
+        }
+
+        // Shortcut for "colorStart"
+        rec._cS = stylize.start;
+        // Shortcut for "colorEnd"
+        rec._cE = stylize.end;
+        // Shortcut for easy date access
+        rec._time = new Date(rec.time);
+
+        var out;
+        try {
+            out = opts.template ? opts.template(rec) : 'No template defined. Use --template.';
+        }
+        catch(e) {
+            // Unprocessable line, display default
+            return emit(line + '\n');
+        }
+        emit(out + '\n');
+        break;
     default:
         throw new Error('unknown output mode: '+opts.outputMode);
     }

package.json

@@ -14,11 +14,12 @@
   },
   "engines": ["node >=0.8.0"],
   "keywords": ["log", "logging", "log4j", "json", "bunyan"],
-
   "// comment1": "'dtrace-provider' required for dtrace features",
-  "// comment2": "'mv' required for RotatingFileStream",
+  "// comment2": "'underscore' required for custom templating in Bunyan CLI",
+  "// comment3": "'mv' required for RotatingFileStream",
   "optionalDependencies": {
     "dtrace-provider": "~0.3 >0.3.0",
+    "underscore": "^1.7.0",
     "mv": "~2"
   },
   "devDependencies": {