 The magazine of the Melbourne PC User Group A Beginner's Tale: Part 12 Ron Wilby |
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Attention - Virus Attack
Last week, a helpful reader sent me a disk with some material for these pages. I haven't read it, because my first move with any disk from an unknown source is to call up McAfee's SCAN program. So, putting the strange disk in drive A:, I typed SCAN A:. SCAN leapt off my hard disk and into action, and quickly told me I had the CANSU virus in the boot sector of the new floppy. Next move, get McAfee's CLEAN to clean it up. Bad news. CLEAN said "sorry, I don't know anything about the CANSU virus." Strange, I thought, that equivalent versions of SCAN and CLEAN know not what the other is about. It happened at this time that my son was staying, complete with his computer. He uses Central Point Anti-virus (CPAV), so gave him the disk with CANSU on it. CPAV promptly informed us that we had the SIGALIT virus, and it would clean it up. 90 minutes later it was still working hard, when we got tired and went to bed.
Next day I decided to try DOS 6 on this unwanted visitor. Getting my DOS prompt, I typed MSAV and Enter. There was a menu and I selected Detect and Clean, having first specified Drive A: Expecting another 90-minute wait, I was walking away when the computer gave a throaty grunt and announced that the disk was clean. A check with SCAN and CPAV confirmed this. Full marks, DOS 6!
Interesting, though, that we are told that CPAV is he parent of DOS's MSAV!
As a footnote to this, Brian Adeney of the Retired Persons SIG has been in touch with Microsoft Technical Support. The conclusion reached was that you shouldn't need to use a continuous virus checker unless your situation is very high risk (an infected floppy is high enough for me!). This "solves" the problem I reported a couple of months back, that with continuous checking DOS 6 is unbearably slow.
DOS 6 Revisited (Again)
Yes, more about DOS 6, which has at least grabbed everybody's attention with its plethora of new features at which we can all hurl insults and contempt. Back off on the contempt, people, there are many advantages for you in DOS 6. See above for one of them.
INSTALLHIGH
An undocumented command which enables you to load Terminate and Stay Resident (TSR) programs from CONFIG.SYS. Why, when you have LOADHIGH from your AUTOEXEC.BAT file doing the same thing. Because INSTALLHIGH allows the use of the F5 and F8 keys, as well as the question mark parameter. If you haven't read your manual, pressing F5 during Startup causes DOS to bypass your CONFIG.SYS and AUTOEXEC.BAT files. F8 enables you to step through CONFIG.SYS one command at a time, nswering Yes or No to each one. This confirms or ypasses each command in turn and when you have finished making a mess, F5 bypasses all the rest of the commands. This procedure doesn't alter your files in any way, so by rebooting (Ctrl+Alt+Del) your startup files will behave normally. Also, for TSRs you don't always need you can save memory by adding the question mark. For example, this command in your CONFIG.SYS file will cause DOS to prompt you before executing. For example
INSTALLHIGH?=C:\MOUSE\MOUSE.COM
will ask for a Y/N answer before loading your mouse driver.
ZAP
To really live dangerously, make this DOSKEY macro called ZAP (make some backups too, and know about your UNDELETE command). At a prompt, enter the following command:
DOSKEY ZAP=ATTRIB -H -S -R $1 $T DEL $1
Then type ZAP (filename) and your file is deleted, even if it has its attribute set at read only, hidden or system.
Path (again)
Many users find the DOS limit on commands of 127 characters particularly painful with long PATH statements. Your PATH statement length can be only 122 characters, since you have to start with PATH=. DOS 6, however, breaks through this limit by allowing PATH statements to be created in CONFIG.SYS with a SET command (PATH statements are normally placed in AUTOEXEC.BAT).
You can use the new EDIT facility to transfer your PATH statement from AUTOEXEC.BAT to CONFIG.SYS and get some practice using EDIT. Type EDIT at your DOS prompt, then open AUTOEXEC.BAT in EDIT. Use the excellent help screens to mark your PATH line as a block, cut it and paste it into CoNFIG.SYS, then insert SET and a space before the PATH statement. Go to the end of the statement and add as many directories as you like, their names being separated by semicolons. Don't forget to save the file before you exit EDIT.
PATH - A better way?
Now get out your PC Update for September 1993, and read the words of Tom Coleman. Tom says "Take all your application programs out of the PATH and write batch files to start them." Your application programs are your wordprocessor, database etc. It's easier than that. If you are using a menu system, such as DOSSHELL, PC TOOLS or the like, then you already have the batch files which start your programs (they may have been written by someone else when your computer was first set up). Use the CD (change directory) command and the DIR command to look for files like wORD.BAT, 123.BAT, PCFILE.BAT. These are the batch files to start Word, Lotus 1-2-3, PC File and so on.
So now you need a directory for these batch files, called say C:\BAT, and you put the BAT directory in your PATH, which now contains PATH=C:\;C:\DOS;C:\UTILS;C:\BAT. That's it, just the root directory C:\, the DOS directory C:\DGS for all the DOS files, and C:\UTILS for all those handy utilities like LIST, MEMMAP, MAPMEM, WHEREIS which you can't live without. Your PATH statement is down to thirty-one characters and that's all you need. Thanks Tom.
That's it for this month, I'll be back in the December issue...
Reprinted from the November 1993 issue of PC Update, the magazine of Melbourne PC User Group, Australia
