C help

[Parnit]

Im trying to make a fairly simple calculator and am running into segmentation faults when I try to exit the program. It occurs precicely at the break and have no idea of how to remedy this any help is greatly appreciated.

#include<stdio.h>
#include<string.h>

int main()
{
float operand_1, operand_2, result;
char operator;
operand_1 = 0;
operand_2 = 0;
result = 0;

/// ignore this just a sample set of instructions for the user not done yet****************
printf("\n");
printf("\n");
printf("When program asks for an operand is means a number\n");
printf("When the operator asks for an operator one of the follwoing options are allowed +,-,*,/\n");
printf("If you want to exit anywhere in the program please enter X or x\n");
printf("Type MS to store result in memory\n");
printf("Type M+ to add result to memory\n");
printf("Type MR to recall 1st or second operand\n");
printf("Type MC to clear memory\n");
printf("Type C to clear result\n");
printf("\n");




printf("Please enter an operand\n");
scanf("%f",&operand_1);
while (1)
{
printf("Please enter a operator\n");
scanf("%s",&operator);

printf("Please enter an operand\n");
scanf("%f",&operand_2);

if (operator == '+')
{
result = operand_1 + operand_2;
printf("The answer is:\n");
printf("%f+%f=%f\n", operand_1, operand_2, result);
operand_1 = result;
}
else if (operator == '-')
{
result = operand_1 - operand_2;
printf("The answer is:\n");
printf("%f-%f=%f\n", operand_1, operand_2, result);
operand_1 = result;
}
else if (operator == '/')
{
result = operand_1 / operand_2;
printf("The answer is:\n");
printf("%f/%f=%f\n", operand_1, operand_2, result);
operand_1 = result;
}
else if (operator == '*')
{
result = operand_1 * operand_2;
printf("The answer is:\n");
printf("%f*%f=%f\n", operand_1, operand_2, result);
operand_1 = result;
}
else if (operator == 'x' || operator == 'X')
{
printf("The program is now being terminated\n");
break; // segmentation fault occurs here****************************************** look here:]
}

}
}

[gerard4143]

I don't know if this is the problem but you have

scanf("%s",&operator);

Where operator is defined as char....Gerard4143

[Parnit]

Do you know of a way to remedy this and also I discovered another problem, if I for example was to check to see if the operator say equalled to +MS it would only see that + sign due to the fact its a char and takes in only one character do you know how I can read everything until the user presses enter.

[gerard4143]

Try looking up fgets() with info or man. It should provide you with functionality your looking for and change operator to a character array...Gerard4143

[Rubberman]

I don't know if this is the problem but you have

scanf("%s",&operator);

Where operator is defined as char....Gerard4143

Exactly. You can use:

scanf("%c", &operator);

Also, in some situations, the return data might be a 2 byte value, so you should use an int value for the operator. Then, mask the unused bits of the operator, and cast it to a char type. It is the overflow of the 1 byte char data that is causing your segfault. The stack has been munged, so when you break, it doesn't know where to go. And while it looks like it occurs at the break, it is actually at the function exit. It's just that the break is the last instruction it can find to give you an address for the segfault. At least, this has been my experience in the past.