-
In this code used to read the contents of a text file I get a illegal operation at the very end right. Here the code
#include <iostream.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
FILE *fp;
class myclass{
public:
void openfile(char *path);
};
int main()
{
char retval;
myclass s;
cout <<"Enter a path to open \n";
cin.getline(&retval, 30, '\n');
s.openfile(&retval);
system("pause");
return 0;
}
void myclass::openfile(char *path)
{
char ch;
if((fp = fopen(path, "r")) ==NULL)
cout << "Cannot open file ERROR";
ch = getc(fp);
while (ch!=EOF){
putchar(ch);
ch = getc(fp);
}
fclose(fp);
}
*How do I embed code in a post? Thanks for your help.
-
You're getting an error because you haven't allocated a buffer for the string. You used char retval. That only has space for one character, you need something like char retval[31] in order to have space for 30 characters and the terminating NULL ('\0').
To embed code use [code] [/code] tags.
-
I've also got an Illegal Operation for one of my programs that I made in PowerC. It's supposed to do some calculation with floating-point. Whenever it gets to the floating-point part, I get an Illegal operation. I worked around it, but I would like to know what's wrong. Is it my compiler(PowerC), or my CPU(AMD486DX-2 80MHz)?
-
What sort of FLOP was it?
-
This is the lines the illegal op happens:
Code:
int diskspace; /*Bytes free got by getdiskfree(); */
int diskfree;
printf("You have %d kbytes left on you drive", diskfree);
printf("Your drive is %f percent free", diskspace/diskfree*100); /* Line the illegal op occurs */
Any ideas?
-
That's because printf is trying to interpret an int as a float since you didn't explicitly cast it.
Try this:
Code:
printf("Your drive is %f percent free", ((float)(diskspace *100.0f) / (float)diskfree));
Just out of interest, is PowerC 16-bit? Because a float is 4 bytes, and a 16-bit int is only 2. It's just a hunch...but I think that if you compiled it 32-bit there wouldn't be an error.
-
PowerC... I don't know if it's 16 bit. It's date says 1989-1995 by MIX software. It was around when the 386 and 486 was out so I'm guessing 32bit. I looked at the arguments for PowerC and there are 2 options for CPU - Compile for 80186 and Compile for 80286. It also says something about 8086 FPU stuff... Yeah. I think it is 16bit, now that I think of it. The good thing about PowerC is that it's very small. All the libraries/binaries/includes take up slightly more than a meg. You can pretty much take it anywhere where there's a PC with a floppy drive!
-
Anything designed for DOS is 16-bit, although you could get 32-bit DOS extenders like DOS4GW which made it nearly a 32-bit environment.
-
Yeah. I think Watcom C/C++ came with a copy.
-
Question:
Is there any source code out there that any of you know about which will make DOS 32-bit?(Like DOS4GW) I've already got DOS4GW(for a game called C-Dogs), but source code could be interesting because then you can design something similar.
