1 files changed, 15 insertions, 8 deletions
diff --git a/node_modules/shelljs/src/head.js b/node_modules/shelljs/src/head.js
index 13d582977..e112e49e1 100644
--- a/node_modules/shelljs/src/head.js
+++ b/node_modules/shelljs/src/head.js
@@ -10,9 +10,9 @@ common.register('head', _head, {
 
 // This reads n or more lines, or the entire file, whichever is less.
 function readSomeLines(file, numLines) {
-  var BUF_LENGTH = 64 * 1024;
-  var buf = new Buffer(BUF_LENGTH);
-  var bytesRead = BUF_LENGTH;
+  var buf = common.buffer();
+  var bufLength = buf.length;
+  var bytesRead = bufLength;
   var pos = 0;
   var fdr = null;
 
@@ -24,8 +24,8 @@ function readSomeLines(file, numLines) {
 
   var numLinesRead = 0;
   var ret = '';
-  while (bytesRead === BUF_LENGTH && numLinesRead < numLines) {
-    bytesRead = fs.readSync(fdr, buf, 0, BUF_LENGTH, pos);
+  while (bytesRead === bufLength && numLinesRead < numLines) {
+    bytesRead = fs.readSync(fdr, buf, 0, bufLength, pos);
     var bufStr = buf.toString('utf8', 0, bytesRead);
     numLinesRead += bufStr.split('\n').length - 1;
     ret += bufStr;
@@ -72,9 +72,16 @@ function _head(options, files) {
 
   var shouldAppendNewline = false;
   files.forEach(function (file) {
-    if (!fs.existsSync(file) && file !== '-') {
-      common.error('no such file or directory: ' + file, { continue: true });
-      return;
+    if (file !== '-') {
+      if (!fs.existsSync(file)) {
+        common.error('no such file or directory: ' + file, { continue: true });
+        return;
+      } else if (fs.statSync(file).isDirectory()) {
+        common.error("error reading '" + file + "': Is a directory", {
+          continue: true,
+        });
+        return;
+      }
     }
 
     var contents;