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project3/node_modules/shelljs/src/ln.js

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+var fs = require('fs');
+var path = require('path');
+var common = require('./common');
+var os = require('os');
+
+//@
+//@ ### ln(options, source, dest)
+//@ ### ln(source, dest)
+//@ Available options:
+//@
+//@ + `s`: symlink
+//@ + `f`: force
+//@
+//@ Examples:
+//@
+//@ ```javascript
+//@ ln('file', 'newlink');
+//@ ln('-sf', 'file', 'existing');
+//@ ```
+//@
+//@ Links source to dest. Use -f to force the link, should dest already exist.
+function _ln(options, source, dest) {
+  options = common.parseOptions(options, {
+    's': 'symlink',
+    'f': 'force'
+  });
+
+  if (!source || !dest) {
+    common.error('Missing <source> and/or <dest>');
+  }
+
+  source = path.resolve(process.cwd(), String(source));
+  dest = path.resolve(process.cwd(), String(dest));
+
+  if (!fs.existsSync(source)) {
+    common.error('Source file does not exist', true);
+  }
+
+  if (fs.existsSync(dest)) {
+    if (!options.force) {
+      common.error('Destination file exists', true);
+    }
+
+    fs.unlinkSync(dest);
+  }
+
+  if (options.symlink) {
+    fs.symlinkSync(source, dest, os.platform() === "win32" ? "junction" : null);
+  } else {
+    fs.linkSync(source, dest, os.platform() === "win32" ? "junction" : null);
+  }
+}
+module.exports = _ln;