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Text File | 1987-05-30 | 11.5 KB | 260 lines

comment * XEQ ----- XEQ - COM File Library and Command Executor This program allows COM files to be stored inside XEQ's code and executed by the command: XEQ command For example, if BEEP.COM has been added to XEQ then: XEQ BEEP will execute the BEEP program stored inside XEQ. The original BEEP.COM can be removed from the hard disk (onto a backup floppy!!!). If the specified command is not in XEQ it is passed to the DOS for execution as if directly typed at the DOS prompt. PURPOSE The purpose is to prevent wasted hard-disk space by those pesky little COM files we don't seem to be able to do without. When hard disks are formatted they are given an allocation size (called a cluster size) and this is typically 2048 or 4096 bytes. So when you save a 7 byte COM file like BEEP.COM, it takes up a full cluster. By combining these COM files into this program or LIBRARY, several COM files can be stored in one file (the XEQ program itself) and still be accessed without this waste in hard disk space. In order to make the body of XEQ as small as possible, only a limited number of options are available. They are XEQ [/R]<command> Execute <command> if it is in the library or passes it to DOS for execution if not XEQ /A(command> Add <command>.COM to library if not existant XEQ /D<command> Delete command from library if existant XEQ /E<command> Extract command from library to .COM file if existant XEQ /L List the <commands> in the library COMMAND DETAILS /R - run a command If no switch is given, the /R is assumed. If the given command name is in the library it is executed directly from there. XEQ internally relocates the stored file in memory so that the memory image is identical to the image if it had been loaded from the COM file on disk. This includes the way DOS loaded a COM file and the pretests for argument suitability and register set up. Thus ALL COM files should execute normally when run from within XEQ. If the command is not found in XEQ then the string is passed to a DOS shell for execution. A second copy of COMMAND.COM is spawned with the command added after the /C switch. Therefore the command can be an internal, external, batch, EXE or COM file. (NOTE: SEE TSR LIMITATION BELOW.) /A - add a command Adds a COM file to the XEQ library. The filename given must either have no extension or .COM and the name part can contain standard DOS wildcards. A drive and/or path may be given to the target file. If the file is already in the library it will not be added. A warning message is given in this eventuality. Similarly if there is insufficient room to add a file, the addition of this file will be skipped with a warning. When wildcards exist, XEQ will attempt to add all files even if a given file cannot be found or is too big. Any attempt to add the current XEQ.COM file to itself (even if renamed under DOS3.x) will be prevented. (In DOS 2.x this safety feature can be thwarted by renaming XEQ.COM. A file called XEQ.COM is the only one excluded from being added.) /D - delete a command Removes the named command from the library. The filename given must either have no extension or .COM and the name part can contain standard DOS wildcards. A prompt asks for confirmation of the delete. 'Y' will delete the command, 'N' will skip deleting the command, 'G' will GO and delete this command and all further matching ones without asking again and 'A' will abort the entire delete process. Obviously 'G' is final and cannot be aborted once selected. Abort will cancel the effect of any 'Y' answers previously, AND NO COMMANDS WILL HAVE BEEN DELETED. /E - extract a COM file When the /E switch is used to extract a COM file, a full path for the resulting file may be specified. If the file already exists at that location, extraction does not occur. The filename given must either have no extension or .COM and the name part can contain standard DOS wildcards. The extracted file has the same date stamp as the COM file it was originally stored from. The file is NOT deleted from the library. /L - list the library files Displays a list of all files stored in XEQ. The original time and date stamp are displayed along with the file's byte size. At the end of the list the remaining space in XEQ is displayed, along with an indication of how much space has been saved by using XEQ (and deleting the original COM files). This computation is based upon the following: DOS 2.x The value is the difference between the total clusters used by XEQ.COM on the default drive and the sum of all the clusters which would have been used on the default drive if each command was in its own COM file. The results can be misleading if say, you run XEQ/L while the drive default points to a floppy with a cluster size of 1024, but the DOS path executed XEQ.COM from the harddisk with a different cluster size. In this case the savings indicated are the bytes saved IF XEQ.COM WAS LOCATED ON THE DEFAULT DRIVE. DOS 3.x The value is as above, but uses the cluster size of the drive it found XEQ.COM on and assumes that the COM files would have been on that drive if they were in seperate files. Under DOS 3.x the savings always relate to the drive the path found XEQ.COM on and is independent of the default drive cluster size. LIMITATIONS As a COM file can only be 64K long, COM files cannot be added to XEQ if this figure would be violated, as XEQ is a COM file itself. The /L command indicates the amount of space left and any attempt to add a file which would exceed the 64k limit is prevented. Any number of COM files can be added until this number is reached. When a command is added or deleted from XEQ, a new copy of XEQ must be rewritten to disk. How it is written back depends on the version of DOS you are running. DOS 2.x users The revised library is always written to the current drive and directory as XEQ.COM, regardless of where the original copy of XEQ was found (it may have been loaded from elsewhere because of DOS's path capability). Therefore to update the original copy of XEQ, the /D or /A commands should be performed in the drive and directory of the original. If not, then the original copy of XEQ will still exist in its original location and the updated version in the current drive and directory. The new version of XEQ will always be called XEQ.COM, regardless of whether the original program was called XEQ.COM or not. DOS3.x users The revised library will be written over the original using the original's name. Thus doing a proper update of the original. The library can be given any name and this will be retained during the updating. MULTIPLE LIBRARIES For DOS 2.x user it is recommended that only one library XEQ.COM exist on the system. As adding or deleting from a renamed library file results in the new copy being called XEQ.COM on the current drive, care would have to be taken to prevent the overwriting of a legitimate XEQ.COM, and the new XEQ.COM would have to be renamed to the original name of the revised library. For DOS 3.x users multiple libraries are more feasible as the updated library is always the original file no matter what it was called or where it was located. Thus maintaining multiple libraries is much simpler. CED (see below) can be used to avoid the need to remember which library contains a given command. TERMINATE & STAY RESIDENT PROGRAMS TSR programs can be stored inside XEQ and will install just like the original program. HOWEVER, NEVER RUN A TSR PROGRAM THROUGH XEQ WHICH IS NOT STORED IN XEQ. When XEQ cannot find a program it passes the name to DOS to run in a shell. If this program is a TSR it will freeze more memory than needed. XEQ has no way of knowing if a program it is about to execute externally is a TSR. Beginning with version 1.10, XEQ will put the name of the file being run into the space between the end of the environment table and the start of the program. This is where DOS 3.x puts the running program name and XEQ will only duplicate this when running under DOS3.x. The purpose of this is to allow the running program to know its own name and to let TSR memory map programs like MAP.COM and MAPMEM.COM show the real program name which is resident. A limitation exists for this however. The name stored is of the form d:/filename.COM. The space available to store this string cannot be increased and is set by the original running of XEQ. So if XEQ was in the root of C: the name would originally be C:\XEQ.COM. So only 3 letters of the program XEQ is running could be used, thus possibly truncating the name. Several possible solutions exist. First call XEQ a new name of 8 letters, or run XEQ from a subdirectory such that the subdirectory name, separating backslashes and the current XEQ name (you may have renamed it to X, possibly) add up to more than 8 characters. Then there will always be room for the full name of the program XEQ is running. USAGE TIP The CED utility and its synonym feature can make the use of XEQ transparent in use. For example, if BEEP.COM is stored inside XEQ then a synonym like SYN BEEP XEQ BEEP will cause BEEP to be run out of the XEQ file just by entering BEEP. DISCLAIMER Hardwood Software Associates guarantees XEQ.COM will do NOTHING useful at all. You use it at your own risk (make backups of the COM files stored within XEQ before deleting them from your hard disk). However, it seems to perform as described here and may be of use to you. Colin J. Stearman [71036,256] Senior Associate HS Associates 143 Ash Street Hopkinton, MA 01748 ====================================================================== EDIT LOG REV DATE NAME DETAIL 1.01 14-MAR-87 C.STEARMAN Fixed bug if COM file name is one character 1.02 27-MAR-87 C.STEARMAN Aligned file size column Added disk bytes saved calc 1.03 1-APR-87 C.STEARMAN Fixed bug if in list if file was longer than 9999 bytes. Fixed error in saved space computation 1.10 2-APR-87 C.STEARMAN Under DOS 3.x updating writes to original file. Also updates command name in environment for MAP, added wildcard, fixed yet another space computation bug, used local stack for external run only 1.11 13-APR-87 C.STEARMAN Revised space saved compute, see note above 1.12 16-APR-87 C.STEARMAN Fixed bug in load_run module which did not initialize stack correctly. Bug manifested it- self when MODE was run internally. Returned bad parameters message 1.13 22-APR-87 C.STEARMAN Fixed wrong message of file not found in /A Improved construction of PSP when running internals. May clean up some compatability problems. Fixed drive validity test. If wild cards in argu- ments, did not set AX correct- ly per DOS loaded. 1.14 29-APR-87 C.STEARMAN Fixed bug when executing ext- ernal commands. Local stack trashed passed command string. Also stack crash caused by allowing XEQ.COM to grow to large. Caused random crashes. Added confirm delete 1.15 30-MAY-87 C.STEARMAN Cleaned up help screen and identified which library file was accessed. Fixed bug in extract where a 1 character filename did not have .COM added to it. ====================================================================== *