Code: Select all

if (UltraEdit.document.length > 1)  // Are at least 2 files opened?
{
   // Define environment for the script.
   UltraEdit.insertMode();
   if (typeof(UltraEdit.columnModeOff) == "function") UltraEdit.columnModeOff();
   else if (typeof(UltraEdit.activeDocument.columnModeOff) == "function") UltraEdit.activeDocument.columnModeOff();

   // Get all lines from first (most left) file.
   UltraEdit.document[0].selectAll();
   var asLinesFileA = UltraEdit.document[0].selection.split("\r\n");
   // Remove last element from the array if it is an empty string
   // because the file ended with a DOS line termination.
   if (asLinesFileA[asLinesFileA.length-1] == "") asLinesFileA.pop();

   // Get all lines from second file.
   UltraEdit.document[1].selectAll();
   var asLinesFileB = UltraEdit.document[1].selection.split("\r\n");
   if (asLinesFileB[asLinesFileB.length-1] == "") asLinesFileB.pop();

   // The file with the smaller number of lines defines the number of lines to compare.
   var nLineCount = (asLinesFileA.length < asLinesFileB.length) ? asLinesFileA.length : asLinesFileB.length;

   // Create a new array for matching strings.
   var asMatches = new Array();

   // Compare the characters of each line.
   for (var nLineIndex = 0; nLineIndex < nLineCount; nLineIndex++)
   {
      var sLineA = asLinesFileA[nLineIndex];
      var sLineB = asLinesFileB[nLineIndex];

      // The shorther line determines the number of characters to compare.
      var nCharCount = (sLineA.length < sLineB.length) ? sLineA.length : sLineB.length;
      for (var nCharIndex = 0; nCharIndex < nCharCount; nCharIndex++)
      {
         // If current character in both lines is not equal, break the loop.
         if (sLineA[nCharIndex] != sLineB[nCharIndex]) break;
      }
      // Are there matching characters at beginning of the line?
      if (nCharIndex > 0)
      {
         // Copy the matching string part to the array for matching strings.
         asMatches[asMatches.length] = sLineA.substr(0,nCharIndex);
      }
   }
   // Are any matching strings found?
   if (asMatches.length)
   {
      // Append an empty string to get finally the matching strings
      // with a line termination also at end of the new file.
      asMatches[asMatches.length] = "";
      // Join the matching strings with a carriage return and
      // a line-feed between each string in user clipboard 9.
      UltraEdit.selectClipboard(9);
      UltraEdit.clipboardContent = asMatches.join("\r\n");
      // Create a new file and make sure that the new file
      // uses DOS line terminators as in the user clipboard.
      UltraEdit.newFile();
      UltraEdit.activeDocument.unixMacToDos();
      // Paste the matching strings into the new file, move the caret
      // to top of this file, clear the user clipboard 9 and make the
      // Windows clipboard the active clipboard before exiting the script.
      UltraEdit.activeDocument.paste();
      UltraEdit.activeDocument.top();
      UltraEdit.clearClipboard();
      UltraEdit.selectClipboard(0);
      asMatches.pop();  // Remove appended empty string.
   }
   // Output a message with number of matching strings found.
   UltraEdit.messageBox("Found "+asMatches.length+" matching string"+((asMatches.length!=1)?"s.":"."));
}
else
{
   UltraEdit.messageBox("There must be at least 2 files opened for this script!");
}