by Rich Pasco
Revised Wednesday, March 30, 2011
Copyright © 2004-2007 Richard Pasco

UNIQUE is a Windows 32-bit console "Filter" application. It reads a text stream from Standard Input and writes to Standard Output a copy where adjacent, duplicate lines have been omitted.

License: Use of UNIQUE is free to end users, but I retain the copyright. This program is shared "as-is" without warranty, promise of support, or liability for consequences of its use. Bug reports are requested, and enhancement requests are invited.

Calling syntax

Command-line invocation is according to the syntax:

UNIQUE <infile.txt >outfile.txt
If either the input file or output file designations are omitted, UNIQUE reads its input from the keyboard or writes it to the display, respectively.

In its alternate form, each output line is prefixed by a parenthesized number indicating how many consecutive copies of that that line appeared in the input:

UNIQUE /count <infile.txt >outfile.txt


  1. Download and open unique.zip.
  2. Move unique.exe into any directory on your command PATH.
  3. Save unique.html (this file) for future reference.

Revision History

April 12, 2007First release
March 30, 2011Re-compiled with new compiler to avoid anti-virus false positive

Author: Rich Pasco