Source Code 1992 March

home *** CD-ROM | disk | FTP | other *** search

/ Source Code 1992 March / Source_Code_CD-ROM_Walnut_Creek_March_1992.iso / msdos / dskutl / lan.arc / LAN.DOC < prev next >

Wrap

Text File | 1988-06-30 | 23.5 KB | 674 lines

FLOPPY-LAN (A floppy based local-area-network) by L. P. Levine 3942 N. Oakland Avenue, Apt 241 Shorewood, WI 53211 This is a Beta test version of a file control system. It is available for use at no cost. Please let the author know about failures and desired features. The programs install.pas, lanmkdir.pas and lancomp.pas and the batch file lan.bat are copyright L. P. Levine 1988. The program touch.exe is copyright Peter Stephen Heitman 1986. This system allows a user to work on two PC computers (so called IBM compatible), one that I will call the Home machine and the other the Work machine and keep a reasonable number of files on both machines current. The program will permit the user to carry a floppy disk containing copies of whatever files have changed from Home to Work and back with no special attention, other than to run a process twice on each machine, once when the user arrives at the machine, and again, just before leaving. Of course the two computers must share a common floppy drive type. The amount of file space supported can be considerably larger than the capacity of a single floppy when the program is used with the TRIM feature. In practice, the user inserts a floppy disk and types "LAN" when arriving at work and again just before leaving the office. When the user gets home, it is only necessary to insert the same disk and type "LAN" before beginning and again after completion of home based work. Any files that have changed are written to and from the floppy disk as the user moves that disk from machine to machine. In writing this document, I wrote part of the documenation at home and part at work. I did software development at both places. Files transferred without attention and at no time did the fingers leave the hand. With the exception of the PICNIX program touch.exe, all programs are presented in source form. The programs install, lanmkdir and lancomp deal only with text files and do no user file manipulation. All file manipulation is done with normal DOS calls (copy, del, mkdir, command, and dir) and with touch. These calls appear in machine written batch files. floppy-LAN Page 1 EXECUTION PROCEDURES The batch file "lan.bat" is custom written by the INSTALL program. Lan.bat consists of 5 main parts. First is an execution of the program "lanmkdir" which reads a list of files to be dually supported and writes a batch file "x1.bat". That batch file is executed next, and outputs to a data file "x1.dat". Third is executed a program "lancomp" which reads that data file and prepares a second batch file "x2.bat" whose purpose is to replace the older version of each of the supported files by the younger. x2.bat is then executed and files are transferred. Finally, in the delivered version of the program, the 3 files named "x?.?at" are deleted. Pictorially it might appear as follows: Process: Data Files: What Happens: ------------ ----------- ----------------- lanmkdir.com <--- lan.fil A list of files is ---> x1.bat changed into a list of DIR commands. x1.bat ---> x1.dat The DIR commands are executed into an output file. lancomp.com <--- x1.dat Differences in dates ---> x2.bat are noted. COPY com- mands are created. x2.bat Files are moved between the floppy and hard drives. floppy-LAN Page 2 SYSTEM INITIALIZATION FLOPPY DISK. A floppy disk must be formatted that is compatible with both systems. A directory called \lan must be put on that disk and one file, a copy of lan.fil, (the list of files supported) or its alias must be put into that directory. LAN will add any other files and directories needed. HARD DISKS. On each of the two host machines a root directory must be created called \lan. In that directory the four files lan.bat, lan.fil, lanmkdir.com and lancomp.com must be placed. (Touch.exe might be put in this directory also.) Lanmkdir and lancomp are Turbo Pascal 3.01 programs whose sources are included with this package. Lan.bat is a file that must be tailored to each of the installations. Lan.fil is a file in which is put the names of the files to be commonly supported. Finally, a subdirectory of \lan on the hard disk called \lan\baq should (but not must) be created. LAN.FIL. This file is the main user interface with the LAN system. In it the user must place all files that are to be maintained on the two machines. The first file supported, and therefore the first entry, must be the file \lan\lan.fil itself. Other file names may be added at any time. An example of lan.fil and instructions for its control are shown in the Technical Details section below. floppy-LAN Page 3 TECHNICAL DETAILS The program uses four files: lan.bat, lanmkdir.com, lancomp.com and lan.fil. They should be installed in the directory \lan on the hard drive of both the Home and Work computers. In addition a subdirectory \lan\baq should be prepared. No special pathing is needed. During execution of the batch file, three files are created, \lan\x1.bat, \lan\x1.dat, and \lan\x2.bat. They are normally deleted at the end of the execution, but their deletion can be inhibited (so that you can look at them) by the removal of the last line of lan.bat. LAN.BAT Lan.bat is a batch file. It is created by running the INSTALL program on each of the two computers used. A typical file is shown below: @echo off lanmkdir BC command /c \lan\x1 lancomp command /c \lan\x2 del x?.?at LANMKDIR Name: lanmkdir - Create batch Directory commands Usage: lanmkdir [FH [FILE]] Version: 1.00 for PC-DOS and MS-DOS (C) Copyright L. P. Levine 1988 -- All Rights Reserved. The options for lanmkdir are: FH The drive letters used for the Floppy and Hard Disks. Default values are A and C. FILE The file used for input. Default value is lan.fil. Lanmkdir is a Turbo Pascal program which may be called with options. In the example above, the options are B and C, where the first letter (B) is the floppy drive to be used and the second letter (C) is the hard drive. It reads data from lan.fil and writes the file x1.bat. The filename of the input file may be added as a second option. Thus: lanmkdir AD SUSIE.FIL will use drives A and D and take data from file SUSIE.FIL. If no options are used the default drives are A and C, and the default file is lan.fil. floppy-LAN Page 4 LAN.FIL The ASCII file lan.fil is the list of files to be supported on the two computers. An example of a typical lan.fil is shown below: \lan\lan.fil \an\NOTES. \llclass\students.dbf \llclass\students.ndx The first file supported is lan.fil itself, to ensure that the two computers are working from the same list. If a file with no extension is desired be sure to include the '.' at the end of its name, as is shown in the example for the file \an\notes. The filenames may be entered case independent and with the usual mix of wildcards. Wildcard use is not encouraged as it becomes increasingly difficult to keep track of the files created when they are used. (For example, a scrap file may be created in the wildcard group. It is dutifully saved and transferred. Later the user may delete the file at home. It may well be returned at the next execution of LAN and will show up again and again like the bad penny.) In the present version no root files may be supported. X1.BAT The output of lanmkdir is the file x1.bat which, for the example above will be: @echo off echo --System Messages, if any----- echo -------------------------------- >x1.dat dir B:\lan\lan.fil >>x1.dat echo -------------------------------- >>x1.dat dir C:\lan\lan.fil >>x1.dat echo -------------------------------- >>x1.dat dir B:\an\notes. >>x1.dat echo -------------------------------- >>x1.dat dir C:\an\notes. >>x1.dat echo -------------------------------- >>x1.dat dir B:\llclass\students.dbf >>x1.dat echo -------------------------------- >>x1.dat dir C:\llclass\students.dbf >>x1.dat echo -------------------------------- >>x1.dat dir B:\llclass\students.ndx >>x1.dat echo -------------------------------- >>x1.dat dir C:\llclass\students.ndx >>x1.dat echo -------------------------------- >>x1.dat When x1.bat is executed, output is generated into x1.dat. An example of x1.dat follows: floppy-LAN Page 5 X1.DAT -------------------------------- Volume in drive B has no label Directory of B:\LAN LAN FIL 384 6-09-88 1:10p 1 File(s) 35840 bytes free -------------------------------- Volume in drive C is DRIVE_C Directory of C:\LAN LAN FIL 384 6-09-88 1:10p 1 File(s) 5181440 bytes free -------------------------------- Volume in drive B has no label Directory of B:\AN NOTES 3141 6-08-88 11:49a 1 File(s) 35840 bytes free -------------------------------- Volume in drive C is DRIVE_C Directory of C:\AN NOTES 3141 6-07-88 11:01p 1 File(s) 5179392 bytes free -------------------------------- Volume in drive B has no label Directory of B:\LLCLASS STUDENTS DBF 75894 5-30-88 12:06p 1 File(s) 35840 bytes free -------------------------------- Volume in drive C is DRIVE_C Directory of C:\LLCLASS STUDENTS DBF 75894 5-31-88 7:12p 1 File(s) 5177344 bytes free -------------------------------- Volume in drive B has no label Directory of B:\LLCLASS STUDENTS NDX 63488 5-30-88 11:47a 1 File(s) 35840 bytes free -------------------------------- (extra lines have Volume in drive C is DRIVE_C have been removed.) Directory of C:\LLCLASS STUDENTS NDX 63488 5-30-88 11:47a 1 File(s) 5177344 bytes free -------------------------------- floppy-LAN Page 6 LANCOMP Name: lancomp - makes copy commands Usage: lancomp [TRIM] Version: 1.00 for PC-DOS and MS-DOS (C) Copyright L. P. Levine 1988 -- All Rights Reserved. The only option for lancomp is: TRIM Causes files on the floppy drive to be reduced in size after transfer to the hard drive. Use only after system has been debugged. Option is case dependent. Lancomp is a program that reads the file x1.dat and writes a command file x2.bat. From the example above it should be clear that the hard disk copy of the file students.dbf is younger than the floppy copy. In x2.bat (below) line 4 creates a new version for the floppy drive, with echo on so that the user sees what is happening. Since the file B:\an\notes is younger than its version on the hard disk, lines 6-8 move a copy to the hard disk, after saving the original version of the file in a backup location (line 6). Finally, if the TRIM option of lancomp is used, lines 10 and 11 replace the floppy copy with a file of length zero bytes. That file occupies NO disk space on drive B, permitting more files to be supported by LAN than will fit on the floppy disk. The file is created and its date is set with the unix like touch command. The only legal option for lancomp is the option TRIM (case matters). The continuous switching of the echo commands permits control of system messages. X2.BAT @echo off echo --System Messages, if any----- echo on line 4 copy C:\LLCLASS\STUDENTS.DBF B:\LLCLASS\STUDENTS.DBF @echo off line 6 copy C:\AN\NOTES. C:\LAN\BAQ >nul: echo on line 8 copy B:\AN\NOTES. C:\AN\NOTES. >nul: @echo off line 10 del B:\AN\NOTES. >nul: line 11 touch 0608114988 B:\AN\NOTES. floppy-LAN Page 7 TOUCH.EXE This file was taken from the shareware PICNIX set and is included (with permission) with this program. Its documentation, repeated below, can be displayed to the screen with the command "touch /h" Name: touch - update last-write times of files Usage: touch [ -c ] [ mmddhhmm[yy] ] file1 ... Version: 1.0 for PC-DOS and MS-DOS (C) Copyright Peter Stephen Heitman 1986 -- All Rights Reserved Distributed with the PiCnix Package (tm) by Peter Stephan Heitman The options for touch are: -c: prevent touch from creating files that did not previously exist [mmddhhmm[yy]]: set the last-write times of the arguments to the given date and time. NOTE: If the date and time are not given on the command line, the last-write times of the arguments are set to the current system time /?: display this description of the program NOTE: If the environment variable TOUCH exists, its value is used to establish default options. floppy-LAN Page 8 OPTIONS The call to the program lanmkdir is: lanmkdir [FH [FILE]] The options are: FH The drive letters used for the Floppy and Hard Disks. Default values are A and C. FILE The file used for input. Default value is lan.fil. Typical calls are: lanmkdir {Drives A and C, file lan.fil} lanmkdir AD {Drives A and D, file lan.fil} lanmkdir BC TEST.FIL {Drives B and C, file TEST.FIL} The call to the program lancomp is: lancomp [TRIM] The options are: TRIM Causes files on the floppy drive to be reduced in size after transfer to the hard drive. Use only after system has been debugged. Is case dependent. Typical calls are: lancomp {Does not reduce size of floppy files after transfer} lancomp TRIM {Reduces size of floppy files after transfer} The directory \lan\baq. Before each transfer of data from the floppy disk to the hard disk, the file about to be replaced is copied to the directory \lan\baq, if that directory exists. Thus, the previous edition of all files on the hard disk is preserved in this backup directory. If the directory does not exist, the feature will fail and no backup will be made. We recommend that the feature be used. floppy-LAN Page 9 ERROR MESSAGES Message: File [filename] does not exist. If the file lan.fil, or its equivalent does not exist, the program lanmkdir will fail with this message. Check to see if you have correctly handled the alias name, if you are using one. Message: File not found Invalid Directory If a file was recently added to the lan.fil list, it might well not be on one of the volumes (either the floppy or hard drive). If that is the case, the batch file X1.BAT will generate this message. It is not an error, merely an unavoidable diagnostic. Message: There is a File On Hard Drive, not on Floppy Drive: C:\dir\file.ext Should I move it to floppy?(y,n) There is a File On Floppy Drive, not on Hard Drive: A:\dir\file.ext Should I move it to hard drive?(y,n) A new file has been created on one machine's hard disk and put into lan.fil. This message requests the user's permission to write it to the floppy, or later, to the hard disk on the other computer. (In the example, the name of the file is \dir\file.ext, in reality, the true name of the file is used.) A "y" or an "n" must be entered. Message: There is a problem with file \dir\file.ext (the floppy file is newer, but is of length zero.) (there may be a clock error, no action will be taken.) Strike a key to continue. This is a message that should never arise. When used with the TRIM option, the files on the floppy drive are replaced with zero length files after being moved to a hard drive. Thus there can be no way for a hard disk file to have an earlier date than this zero length floppy file. If, however, the time or date was wrongly set on one computer, or if a computer battery clock stops, or if the touch command was used to backdate a file, time may actually run backwards. This message reports on that event. No data transfer occurs. floppy-LAN Page 10 Message: Unable to create directory In batch file X2.BAT, an attempt to move a NEW file to either the hard or floppy disk is always preceded by an attempt to create the associated directory. If that directory already exists, this message will result. It is not an error, merely an unavoidable diagnostic. Message: Insufficient disk space It means what it says; bad news. Using the TRIM option will enormously reduce the probability of having this message appear when it applies to a floppy transfer disk. If you are using the TRIM option and change files controlling a large amount of supported filespace in one session, then this message can appear. Corrective action might be: split the system into several small parts, make fewer changes at once, deal with smaller files. floppy-LAN Page 11