A.C.G.Saunders@newcastle.ac.uk (Aidan Saunders) (01/23/91)
Is there any way of disabling DOS internal commands ? Alternatively can DOS be persuaded to execute a program of the same name as a DOS internal command without explicitly specifying a path ? The question arises because I am wondering how we could 'persuade' users to use Vcopy - the copy program from McAffee Associates that checks for viruses in the files it copies. Obviously this can be used by running it as vcopy - but undergrads being what they are will not bother to read notices or remember to specify 'vcopy' instead of 'copy'. So - how could we arrange for vcopy to be invoked when the user says copy ? Any ideas ? Aidan -- ---------------------------------------------- ARPA :: a.c.g.saunders@newcastle.ac.uk UUCP :: ...!ukc!newcastle.ac.uk!a.c.g.saunders ----------------------------------------------
iisakkil@niksula.hut.fi (Mika R Iisakkila) (01/24/91)
A.C.G.Saunders@newcastle.ac.uk (Aidan Saunders) writes: > Is there any way of disabling DOS internal commands ? Alternatively > can DOS be persuaded to execute a program of the same name as a DOS > internal command without explicitly specifying a path ? Use a binary editor and patch the command names in command.com into something else. You can't change the lenght of the command names, but changing 'copy' into 'ypoc' or something should fool the users for a while... The command name string arrays are near the end of command.com and easily found. You might probably want to patch a renamed copy of command.com and use the config.sys's SHELL command.
nee@cf_su20.Sbi.Com (Robert Nee) (01/24/91)
> Is there any way of disabling DOS internal commands ? Alternatively > can DOS be persuaded to execute a program of the same name as a DOS > internal command without explicitly specifying a path ? The easiest way to disable internal commands is to alter a second copy of COMMAND.COM with something like Norton. Search for the text of the command you wish to alter. Notice that the commands are listed on all uppercase. Simply changing the command to lowercase will disable it. This method works because DOS converts you command line to uppercase before proccessing it. It then performs a case-sensitive compare with all of the internal commands. Since "COPY" won't match "copy" the command is effectively disabled. In addition changing the command to lower case will allow you to easily find where the change was made in case you wish to alter it later. If you rename VCOPY to COPY users will really be executing a virus free copy. Remember, never try to patch your only copy of COMMAND.COM. Always attempt patches on a backup copy. Robert F. Nee <nee@cf_su20.sbi.com>
ted@helios.ucsc.edu (Ted Cantrall) (01/24/91)
>Is there any way of disabling DOS internal commands ? Alternatively >can DOS be persuaded to execute a program of the same name as a DOS >internal command without explicitly specifying a path ? ------------------------------- Search COMMAND.COM for the command "copy" and edit the name to something like "kopy". Rename "vcopy" to "copy". The details of editing COMMAND.COM are very fuzzy, so I can't help you more than that. Good luck! BTW, be sure to document the change so later people can be aware and/or be able to change it back. -ted- ------------------------------------------------------------------------------- ted@helios.ucsc.edu |"He has showed you, O man, what is good; and what does the W (408)459-2110 |Lord require of you but to do justice and to love kindness H (408)423-2444 |and to walk humbly with your God?" Micah 6:8 (RSV)
roger@wrq.com (Roger Fulton) (01/25/91)
In article <1991Jan23.120842.3032@newcastle.ac.uk> A.C.G.Saunders@newcastle.ac.uk (Aidan Saunders) writes: >Is there any way of disabling DOS internal commands ? Alternatively >can DOS be persuaded to execute a program of the same name as a DOS >internal command without explicitly specifying a path ? > CED synonyms accomplish this. Roger Fulton roger@wrq.com
roy%cybrspc@cs.umn.edu (Roy M. Silvernail) (01/25/91)
A.C.G.Saunders@newcastle.ac.uk (Aidan Saunders) writes: > Is there any way of disabling DOS internal commands ? Alternatively > can DOS be persuaded to execute a program of the same name as a DOS > internal command without explicitly specifying a path ? Under 4dos, you can remove or rename any built-in. In fact, I have renamed the resident 'list' to 'look', and redirected 'list' to point to LIST.COM. 4dos can be told to use upper-case, and generally look just about like command.com. -- Roy M. Silvernail -- roy%cybrspc@cs.umn.edu - OR- cybrspc!roy@cs.umn.edu Department of redundancy department, or "Take the long way home...": main(){system("perl -e '$x = 1/50; print \"Still just my \\$$x!\n\"'");} [new year, new .sig, same ol' cyberspace]
fisher@sc2a.unige.ch (01/25/91)
In article <1991Jan23.120842.3032@newcastle.ac.uk>, A.C.G.Saunders@newcastle.ac.uk (Aidan Saunders) writes: > Is there any way of disabling DOS internal commands ? Alternatively > can DOS be persuaded to execute a program of the same name as a DOS > internal command without explicitly specifying a path ? Several people replied: "Run a patched version of COMMAND.COM, in which the "COPY" string has been changed." If you use some COMMAND-enhancer (I'm thinking of ANARKEY), or a COMMAND replacement (4DOS comes to mind), the easiest solution is to work with aliases: transparent, easy to understand and to maintain (and no worries whether binary patches of COMMAND.COM violate it's copyright :-) Just an opinion... Markus Fischer, Dpt of Anthropology, Geneva CH