1 files changed, 104 insertions, 0 deletions
diff --git a/node_modules/shelljs/src/head.js b/node_modules/shelljs/src/head.js
new file mode 100644
index 000000000..13d582977
--- /dev/null
+++ b/node_modules/shelljs/src/head.js
@@ -0,0 +1,104 @@
+var common = require('./common');
+var fs = require('fs');
+
+common.register('head', _head, {
+  canReceivePipe: true,
+  cmdOptions: {
+    'n': 'numLines',
+  },
+});
+
+// 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 pos = 0;
+  var fdr = null;
+
+  try {
+    fdr = fs.openSync(file, 'r');
+  } catch (e) {
+    common.error('cannot read file: ' + file);
+  }
+
+  var numLinesRead = 0;
+  var ret = '';
+  while (bytesRead === BUF_LENGTH && numLinesRead < numLines) {
+    bytesRead = fs.readSync(fdr, buf, 0, BUF_LENGTH, pos);
+    var bufStr = buf.toString('utf8', 0, bytesRead);
+    numLinesRead += bufStr.split('\n').length - 1;
+    ret += bufStr;
+    pos += bytesRead;
+  }
+
+  fs.closeSync(fdr);
+  return ret;
+}
+//@
+//@ ### head([{'-n': \<num\>},] file [, file ...])
+//@ ### head([{'-n': \<num\>},] file_array)
+//@ Available options:
+//@
+//@ + `-n <num>`: Show the first `<num>` lines of the files
+//@
+//@ Examples:
+//@
+//@ ```javascript
+//@ var str = head({'-n': 1}, 'file*.txt');
+//@ var str = head('file1', 'file2');
+//@ var str = head(['file1', 'file2']); // same as above
+//@ ```
+//@
+//@ Read the start of a file.
+function _head(options, files) {
+  var head = [];
+  var pipe = common.readFromPipe();
+
+  if (!files && !pipe) common.error('no paths given');
+
+  var idx = 1;
+  if (options.numLines === true) {
+    idx = 2;
+    options.numLines = Number(arguments[1]);
+  } else if (options.numLines === false) {
+    options.numLines = 10;
+  }
+  files = [].slice.call(arguments, idx);
+
+  if (pipe) {
+    files.unshift('-');
+  }
+
+  var shouldAppendNewline = false;
+  files.forEach(function (file) {
+    if (!fs.existsSync(file) && file !== '-') {
+      common.error('no such file or directory: ' + file, { continue: true });
+      return;
+    }
+
+    var contents;
+    if (file === '-') {
+      contents = pipe;
+    } else if (options.numLines < 0) {
+      contents = fs.readFileSync(file, 'utf8');
+    } else {
+      contents = readSomeLines(file, options.numLines);
+    }
+
+    var lines = contents.split('\n');
+    var hasTrailingNewline = (lines[lines.length - 1] === '');
+    if (hasTrailingNewline) {
+      lines.pop();
+    }
+    shouldAppendNewline = (hasTrailingNewline || options.numLines < lines.length);
+
+    head = head.concat(lines.slice(0, options.numLines));
+  });
+
+  if (shouldAppendNewline) {
+    head.push(''); // to add a trailing newline once we join
+  }
+  return head.join('\n');
+}
+module.exports = _head;