title: How to look for the difference between two large files in tcl?
body: <p>I have two files, the some of the contents of these might be common in both. (say file <code>A.txt</code> and file <code>B.txt</code>)
  Both the files are sorted files. 
  I need to get the difference of file <code>A.txt</code> and <code>B.txt</code>, ie, a file <code>C.txt</code> which has contents of A except the common contents in both.</p>
  
  <p>I used the typical search and print algorithm, ie, took a line from <code>A.txt</code>, searched in <code>B.txt</code>, if found, print nothing in <code>C.txt</code>, else print that line in <code>C.txt</code>.
  But, I am dealing with files with huge # of contents, and thus, it throws error: <code>failed to load too many files</code>. (Though it works fine for smaller files)</p>
  
  <p>Can anybody suggest more efficient way of getting <code>C.txt</code>?
  Script to be used: TCL only!</p>