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DOS开发编程 & 发展交流（开发室） » How to read and write DOS variables in C?

Floor1　kang2008	Posted 2008-12-27 22:12
初级用户　Posts 14　Credits 28
How does C read and write DOS variables? Or, how can a program written in C read/modify DOS variables or assign the return value to a DOS variable? For example, there is a variable in DOS: vCdrom=D:, but I just want the first character. C can use the left() function to intercept, but there seems to be no such command in DOS.

Floor2　kemyliu	Posted 2009-01-07 18:05
新手上路　Posts 8　Credits 16
DOS doesn't have such a function. Write a conversion program in C.

Floor3　zhgwbzhd	Posted 2009-01-08 11:09
高级用户　Posts 187　Credits 506
I don't understand what you mean. But it can be implemented as follows. For example, you have a program A.exe, and after it finishes, it returns a value, such as maybe 1 or 2. Execute different programs B.exe or C.exe according to your return value. It can be implemented through batch processing. A.exe(Execute A) if errorlevel 2 goto L_2 if errorlevel 1 goto L_1 goto L_end :L_2 C.exe goto L_end :L_1 B.exe goto L_end :L_end

Floor4　hepu	Posted 2009-01-16 15:49
新手上路　Posts 6　Credits 11
Try the main program return value. int main() { int x=0; .... retun x; }