%%% %%% %%%% %%% %% %%%%% %%%% %%%% %% %%%% %% %% %% %% %%% %% %% %% %% %% %% %% %% % %% %% %% %%%% %% %% %% %% %%%% %% %%% %%%%% // // //// ////// ////// // \\ \ \\ \\ \\ \\ \\ \\ \\ \\ // /// // //////// ////// ////// // \\\\ \\\\ \\ \\ \\ \\ \\ /// /// // // // // // // [ Mind Warp - Volume #4, Issue #07, File #062 ] [ "Compression Utilities" by >Anonymous< ] ------------------------------------------------------------------------------ Compression Utilities [Anonymous] ------------------------------------------------------------------------------ Compression Comparisons between .ZIP, .ARJ, and .LZH using references from a compressed file(.TXT, .EXE, .GIF.) (* WARNING : THIS FILE CONTAINS NO HUMOR, SICKO STORIES, OR INTERESTING MATERIAL. IT IS MERELY A FACTUAL ARTICLE ON COMPRESSION. MIND WARP HAS HAD NO FACTUAL ARTICLES, SO I WROTE THIS ONE. READ IT. *) There are many different compression utilites available for use in the pc world to shrink the average filesize for more room on the host compters hard drive. Some of the most common for the DOS operating system include PkZip, Arj, and Lharc. These utilites have obvious advatages for the user. Creating more disk space, packaging many files into a small mobile file that can be extracted elswhere, and the ease of moving such files are certainly transparent. However, these compression utilites all use a different algorythm for their storage capabilites, and as data suggests, these different algorythm's are not all suitable for compressing all types of files with the best compression ratio. Indeed, in some instances, the compression utility can actually increase the size of the file. The procedure below outlines the use of three compression utilites, PkZip, Arj, and Lharc, and their induvidal results in the compression of three types of files, ascii text files (.TXT), executables (.EXE), and graphics (.GIF) files. As the data suggests, different compression utilites can be more effective on certain files than others. Procedure Three files were randomly selected off of a hard drive contributed by a willing pc user. These files were as follows: FileName Size Type ------------ ------- ----------------- SCANDISK.EXE 124,262 Executable GENERIC1.TXT 86,303 Ascii Text File TESLA-02.GIF 63,885 GiF Graphics File The files were then compressed using the three compression utilites keeping the same filename, with a new extension. (ie. .ZIP, .ARJ, or .LZH.) Data + Results. FileName Compression Name Original Size Compressed Size Rank ------------- ---------------- ------------- --------------- ---- SCANDISK.EXE SCANDISK.ZIP 124,262 120,715 #3 SCANDISK.EXE SCANDISK.ARJ 124,262 120,696 #2 SCANDISK.EXE SCANDISK.LZH 124,262 120,666 #1 ------------- ---------------- ------------- --------------- ---- GENERIC1.TXT GENERIC1.ZIP 86,303 31,716 #1 GENERIC1.TXT GENERIC1.ARJ 86,303 31,925 #2 GENERIC1.TXT GENERIC1.LZH 86,303 33,517 #3 ------------- ---------------- ------------- --------------- ---- TESLA-02.GIF TESLA-02.ZIP 63,885 63,775 #1 TESLA-02.GIF TESLA-02.ARJ 63,885 63,911 #3 TESLA-02.GIF TESLA-02.LZH 63,885 63,834 #2 ------------- ---------------- ------------- --------------- ---- Conclusion The data shows that not all the compression utilites work the same on certain files. For executables (.EXE), Lharc is clearly the utility to use. For ascii text (.TXT), and for graphics files such as GiF (.GIF), PkZip should be used. Arj never placed 1st in any of the trials, but one would note that Arj actually increased the file size when attempting to compress the Gif file. All in all, either PkZip or Lharc are recommended for use in the compression field. Both have excellent help available, and are well documented. Keep in mind however, that these are not the ONLY compression programs available for the pc user. Not mentioned in this article were such compression utilites as .ZOO, and .UC2. ============================================================================== Call Hell's Kitchen - (301) 989-8510 ==============================================================================