BEC.SHAPIN@USC-ECL.ARPA (Ted Shapin) (07/10/85)
Some of the public IBM bulletin board systems are using a program called ARC.EXE to pack related files into "archives". In the past, this has been done with "LU*" library utility programs. I think the library utility programs are to be preferred for the following reasons: . 1) They are public domain, whereas ARC.EXE is a product of System Enhancement associates and asks for a "donation". . 2) The LU programs are well documented. Gary Novosielski wrote the first version in C. The documentation for current versions is in LUDEF5.DOC. Some versions have source available. . 3) Library programs exist on mainframes such as Unix and DEC-20 that will handle .LBR files. . 4) The format is compatible with CP/M-80 .LBR files, so the CP/M user can handle them (altho not run the executable). . 5) LBR utilities exist to run executable programs directly from the library file. . 6) Paul Homchick and Vernon Buerg have written high performance versions of LU* programs for the IBM-PC. LUE201.COM is 2688 bytes and will extract all members and unsqueeze them if necessary at the same time. . 7) ARC does result in slightly smaller files. Comparing library files with archive files shows .LBR files to be about 1000 bytes larger, for .LBR files from 11000 to 40000 bytes in size, apparently because a better algorithm is used for packing repeated characters in .EXE files. However, I believe the other reasons listed above justify using the .LBR programs. . Ted Shapin -------