Simplify color config setting

doc/cli/config.md

@@ -501,6 +501,9 @@ It cannot be set from the command line, but if you are using npm
 programmatically, you may wish to send logs to somewhere other than
 stderr.
 
+If the `color` config is set to true, then this stream will receive
+colored output if it is a TTY.
+
 ### long
 
 * Default: false

lib/help-search.js

@@ -163,7 +163,7 @@ function helpSearch (args, silent, cb) {
             })
             out = newOut.join("")
           }
-          if (npm.config.get("color")) {
+          if (npm.color) {
             var color = "\033[31;40m"
               , reset = "\033[0m"
           } else {

lib/ls.js

@@ -205,7 +205,7 @@ function makeArchy (data, long, dir) {
 }
 
 function makeArchy_ (data, long, dir, depth, parent, d) {
-  var color = npm.config.get("color")
+  var color = npm.color
   if (typeof data === "string") {
     if (depth < npm.config.get("depth")) {
       // just missing

lib/npm.js

@@ -262,17 +262,36 @@ function load (npm, conf, cb) {
     //console.error("about to look up configs")
 
     ini.resolveConfigs(conf, function (er) {
+      var color = npm.config.get("color")
+
       log.level = npm.config.get("loglevel")
       log.heading = "npm"
       log.stream = npm.config.get("logstream")
-      switch (npm.config.get("color")) {
+      switch (color) {
         case "always": log.enableColor(); break
         case false: log.disableColor(); break
       }
       log.resume()
 
       if (er) return cb(er)
 
+      // see if we need to color normal output
+      switch (color) {
+        case "always":
+          npm.color = true
+          break
+        case false:
+          npm.color = false
+          break
+        default:
+          var tty = require("tty")
+          if (process.stdout.isTTY) npm.color = true
+          else if (!tty.isatty) npm.color = true
+          else if (tty.isatty(1)) npm.color = true
+          else npm.color = false
+          break
+      }
+
       // at this point the configs are all set.
       // go ahead and spin up the registry client.
       var token

lib/search.js

@@ -253,9 +253,9 @@ function addColorMarker (str, arg, i) {
 function colorize (line) {
   for (var i = 0; i < cl; i ++) {
     var m = i + 1
-    var color = npm.config.get("color") ? "\033["+colors[i]+"m" : ""
+    var color = npm.color ? "\033["+colors[i]+"m" : ""
     line = line.split(String.fromCharCode(m)).join(color)
   }
-  var uncolor = npm.config.get("color") ? "\033[0m" : ""
+  var uncolor = npm.color ? "\033[0m" : ""
   return line.split("\u0000").join(uncolor)
 }