• C

Shell ?

hi guys,
i would like to know how to do a dos shell like the one in turbo c or borland c++.i wanna know how to save the current environment and then restore it back.I am working in borlannd c++ under dos platform.
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arnondConnect With a Mentor Commented:
I think I understand what you're trying to do:
do something like this:

while (1)

read_command_from_stdin() will read the command line (with scanf() or something like that) into a command string.
understand_what_command_was_given_and_execute_appropriate_routine() will find out which command was enetred, see if it's a known command and execute the relevant routine or function for that command.

If you need more help, just ask.
Arnon David.

This has nothing to do with C so it is the wrong topic area.

However, what you could do is pipe the output of "set" to a file  and edit the file to make a suitable batch file. This can then be executed to restore your environment.
girishrAuthor Commented:
hi braveheart,
i did not understand ur reply at all.well i am doing a program in C in which i need to do a dos shell.i hope u understand my Q right...please tell me why it has nothing to do with c (as u said)
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Sorry, I misunderstood your question. I did not realise that you are trying to write a shell but thought you were having trouble using the DOS environment. After all, DOSSHELL is a specific product.
as for saving the current environment, use a struct that will hold the environment inf and have a file to write all the environment info to and then you can always read from it and save changes to it.

Arnon David.
it was long time ago, when I programmed on DOS, but as far as i remember

"i would like to know how to do a dos shell ..."
aren't you supposed to free as much memory as you can (leave only a small module in memory) and start new command proccess (execute COMMAND.COM)

"i wanna know how to save the current environment and then restore it back"
as far as i remember a proccess CAN'T change the enviroment of its father proccess. Every proccess receives a copy of the enciroment of its father proccess, manipulates it and then frees it. Are you trying to inform your father procces about changes in your own enviroment ?

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