YGrep Search Engine

Regular expression library/DLL
for approximative, Soundex and regular expressions


The YGrep Search Engine is a text search and replace library to be used with any kind of Windows application. It provides such unusual features as:

  • Approximative search based on Baeza-Yates algorithm to find a pattern which is only partly known (also known as search with erroneous patterns). An error is a character replacement. For example, you can search for pattern with 1 error (at most) and it will match patternpittern and Pattern while stepping over lantern (2 errors).
  • Regular expression search modelled on the Unix utility named GREP (it looks like the DOS/Windows wildcards on steroids). It is particularly useful for complex searching with the help of its specific search “language” to describe the pattern you look for. For example, you can search for ^pattern to look for pattern at the beginning of a line; or for [pl]a[nt]tern to look for either pattern or lantern. Look into the Help file for an extensive description of the pattern language. Or go to the online definition of regular expression syntax.
  • Soundex-based search where text is matched against patterns following a presupposed law helping in recognizing very poorly written english words (more simply put: by collapsing similar sounds into common sonorities, Keller and Keiler are identified as sounding similar).

The YGrep Search Engine is also greatly improved other most similar tools by providing outstanding features like:

  • Both search and replace functions (most libraries only provide search capability)
  • Support of many languages including C/C++, Delphi, but also FoxPro, and Visual Basic (bringing regular expression syntax to such languages lacking this feature)
  • Simple file operations for immediate application (including regular expression handling, of course)
  • Combined search operation (Boolean operators) for the power user/programmer
  • Optional error messages/dialog-boxes for high-end applications
  • Free bonus YFind search application (similar to grep(1) from Unix)
    Fairly good support for internationalization


Based upon the features just described, the YGrep Search Engine appears as a needed library for all those that are developing:

  • Internet/Intranet search engines,
  • Sort-filter-and-store machines, like E-mail filters,
  • Database searching tools,
  • Text editors.

The YGrep Search Engine will improve them to a level that most end-users will find very useful but that the developer may fear to implement because of the complexity of the algorithms involved.

All those applications can benefit from the addition of the search capability of the YGrep Search Engine (and specifically of the regular expressions).


Better quality

The YGrep Search Engine is truly tested software. It has been widely available and used since 1993. This means that you get a mature library in a stable state rather than a quick-and-dirty bunch of minimal features. Notably, several of the most widely available source code library are bug-ridden to a point that may appear surprising to most programmers.

Faster development

While some of the capabilties of the YGrep Search Engine may be written by most C/C++ developers, it is often overkill to re-invent the wheel (we have a full set of wheels ready for you :-). Furthermore, you certainly do not want to spend time debugging all this automaton code that you did not look into since you graduated out of the Computer Science course.

High performance and flexibility

The YGrep Search Engine offers a good compromise between performance and usability, where other products may sacrifice all ease-of-use to absolute performance (how do you get that performance if you have to dig into source code before being able to merely search for a string in a file?).

Actual support

Forget about difficulties in understanding the library interface. Registered users receive actual documentation (not only a few Unix cryptic man pages).

You will also receive actual help direct from the developer using E-mail, phone, or fax at your convenience.

Real commitment to customer satisfaction

As I am listening to your real needs, you can get a real support from real people.

Some of our Customers

The YGrep Search Engine has attracted Customers of all sizes appreciating its flexibiity and ease of use. Amoung the most well-known ones, most people will recognize a few very well-known companies characterized by the high-level of excellence they ask from their providers:

  • Federal Express
  • Intel Corp.
  • Intuit
  • Trillium Software

Like these top-flyers and many other smaller companies or individual entrepreneurs, you can get the YGrep Search Engine in your most business-critical applications.


If you want to download it, here are a few FTP servers you can use. I only tried to give as much variety as possible in order to avoid bottlenecks. These will be changed in the future to reflect distribution.

Get the YGrep Search Engine from the net

This one is the most recent version for WIN32S, Windows 95, Windows 98, Windows NT v4.0 and v5, Windows XP.