From d5caaa7877b095add2ee292c22f26f7e6ad599d6 Mon Sep 17 00:00:00 2001
From: David Majda <david@majda.cz>
Date: Wed, 26 Jan 2011 14:01:57 +0100
Subject: [PATCH] Nicer messages in command-line mode on read/write errors

---
 bin/pegjs | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/bin/pegjs b/bin/pegjs
index 20e5e54..7693eca 100755
--- a/bin/pegjs
+++ b/bin/pegjs
@@ -103,13 +103,25 @@ switch (args.length) {
     var inputStream = process.openStdin();
     var outputStream = process.stdout;
     break;
+
   case 1:
   case 2:
-    var inputStream = fs.createReadStream(args[0]);
-    var outputStream = fs.createWriteStream(
-      args.length == 1 ?  args[0].replace(/\.[^.]*$/, ".js") : args[1]
-    );
+    var inputFile = args[0];
+    var inputStream = fs.createReadStream(inputFile);
+    inputStream.on("error", function() {
+      abort("Can't read from file \"" + inputFile + "\".");
+    });
+
+    var outputFile = args.length == 1
+      ? args[0].replace(/\.[^.]*$/, ".js")
+      : args[1];
+    var outputStream = fs.createWriteStream(outputFile);
+    outputStream.on("error", function() {
+      abort("Can't write to file \"" + outputFile + "\".");
+    });
+
     break;
+
   default:
     abort("Too many arguments.");
 }