DOS Utilities For Your PC

Editor’s note: This is the second article in a three-part series on utilities for IBM PCs or compatibles. For the first part, on enhancing input/output operations, see February 8, 1988, p. 22. A future article will deal with desktop utilities. The disk operating system (DOS) that you purchase to run on your personal computer consists primarily of a set of routines that application programs can call upon, together with a facility for loading programs. The various built-in commands like “copy” and “dir” (for “directory”) and the separately supplied commands like “chkdsk” (for “checkdisk”) are just icing on the cake. Given the price, these add-in programs are an extraordinary deal, but many are incredibly primitive. Even worse, DOS can do dangerous things like overwriting a file without first waming you when you copy a file of the same name. Fortunately, one is not limited to DOS commands. There is a wide array of utilities that replace many of these basic DOS services. I’ll limit my discussion to utilities directly related to the operating system or the disk itself. I won’t discuss editors (the DOS line editor EDLIN is mainly good as a source of jokes) or debuggers (the DEBUG and CHKDSK programs are the most powerful and impressive of the DOS add-ins). The editing tools provided at the DOS command line (the A> prompt) are absurd: not only are they limited, they use non-intuitive keys like to recall the last command you issued. A number of excellent programs allow you to edit these commands and perform other tasks. These programs have several features in common. First, they let you edit the command line using arrows and inserts and often supply additional commands. More important, they keep a stack of previous commands, not just the last one issued that you can recall and edit. The best of these programs will keep the commands stacked in place so you can easily reissue a group of commands. For example, the edit, compile, debug cycle when you program or produce a manuscript in TEX requires that you issue the same set of commands several times in a row. A command processor will let you use the arrow keys to reissue the commands automatically. (See THE SCIENTIST, January 11, 1988, pp. 18-21 for more on TEX.) These command-line programs also allow you to use aliases or synonyms. For example, when I type “a,” on the command line, my computer understands it to be “dirA:”—that is, “list a directory of the files on drive A.” I have used the command line processor PCED for a long time, and I think it’s the best one available. If you don’t feel like buying a program, there is also a free program called CED—a precursor to PCED—you should consider. TOPDOS adds a resident DOS shell (of the kind discussed later) to the command line functions. COMMAND PLUS is a full replacement for command.com that includes an intelligent replacement for DOS’ batch file facility. TALL SCREEN includes a screen management system that allows you to recall output that has scrolled off the screen. It turns a DOS session into something akin to a full-screen editor or word processor in that the up and down arrows move the cursor on the screen where you can edit and reissue the DOS commands. TMU is the simplest of these programs and most limited; its virtue is that it takes up very little memory, making it most suitable for laptop PCs. If you are used to running the UNIX operating system on a minicomputer and want a UNIX-like interface to DOS (but with DOS compatibility to run standard PC software), you should consider POLYSHELL and MKS TOOLKIT. DOS comes with a batch facility that allows you to nin a sequence of commands by typing the name of a single batch file. For example, you could arrange to run your word processor sandwiched with commands to load and remove a set of macros from a keyboard macro program. The batch facility also includes some rather primitive elements of a language: you can pass parameters to the batch file (such as the name of the file you want your word processor to load) but you can’t manipulate these parameters, nor can you get input from users. For example, with DOS tools alone there is no way to ask the user (who may be you!) if he or she wants to do a backup and branch the operation of the batch file. Moreover, there are no provisions for prefeeding keystrokes to programs, so you can’t use a batch file to load a program and answer the first few questions that it insists on asking you. There are free programs that meet one or two of these needs. For example, there are programs that let you query the user and get the answer in the error level. (The error level is an internal DOS parameter you can use within the batch facility to do some elementary branching.) You could use one of these programs to ask if the user wants to back up a file and have the error level set to 1 if the answer is N its no and 0 if it is yes and then use the batch file cede fragment:if errorlevel 1 goto :skip copy FILENAME B: :skip that uses the “if errorlevel” and “goto” commands discussed in your DOS manual. STACKEY (which I hesitate to mention since I helped develop it, but since version 2.0 is free I will anyway) stacks keystrokes and even color changes on the enhanced graphics adaptor, if your PC is equipped with one. But the best way of enhancing your batch files is with a full-fledged environment that gives you control during batch processes. EXTENDED BATCH LANGUAGE is a shareware offering that gives you control over DOS variables as well as user-defined variables and many other language " features. In effect, it has much the feel and functionality of the computer language BASIC COMMAND PLUS, mentioned above, includes a full fledged “script” language with the flavor of Pascal. BEYOND BAT is a third batch replacement with somewhat more power but at the cost of more complexity than the first two programs. A final possibility is PERSONAL REXX, originally developed as a batch processor for IBM’s VM mainframe operating system. Enhancers The tools DOS provides for choosing which files to work on are fairly primitive. One can only pick multiple files for a command to operate on by using the DOS wildcards * and ?. Moreover, visualizing and maneuvering the directory tree isn’t easy using DOS tools alone. There is a genre of software called a “DOS shell” that manipulates the files on your disk. Typically, a shell gives you a full-screen display of the file names. You then use your cursor to mark the files you’re interested in with a single keystroke. Once the files are identified, you can do a bulk operation like erase the marked files or copy them all somewhere. In most cases, shells do better than DOS in preventing accidental overwriting of files and in handling those nasty situations when you get the message “Read Error: Diskette Full.” DOS commands act only on the current directory, whereas many of these programs allow you to do an operation like “erase *.bak” (that is, erase all temporary backup files) on an entire disk at once. Some will display a visual tree of the disk directories and allow you pick a directory with a cursor. While DOS shells are of some use on systems equipped only with floppy disks, they are essential on systems with hard disks where file management becomes mandatory. There are literally dozens of this type of program, but to my mind the best are QDOS and XTREE PRO. The slickest of the shareware programs is probably OVERVIEW These programs often have limited file viewers and/or editors. One of the most celebrated file viewers is a share program called LIST that I recommend highly. In addition to the full-screen file manipulators like QDOS, there are a few command-line file manipulators. I use DX, a shareware program. It has about 70 command line switches you can place in batch files or aliases and then forget about them. For example dx *.bak/ if/del/v-will delete all BAK files on the disk starting from the root directory (if stands for “file find”). By default, DX will list each matching file and ask if you’re sure that you really want to delete it.

DOS Utilities For Your PC

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