Lab14

calc.c

@@ -1,33 +1,42 @@
 #include <stdio.h>
 #include "operators.h"
+#include "my_fscanf.h"
+
+double calc(double op1, double op2, char op) {
+	double (*func)(double, double);
+	double ans;
+	switch(op) {
+		case '+': 
+		func = add;
+		break;
+		case '-':
+		func = minus;
+		break;
+		case '*':
+		func = mul;
+		break;
+		case '/':
+		func = div;
+		break;
+	}
+	ans = func(op1, op2);
+	return ans;
+}
 
 int main(){
 	FILE *fp = NULL;
-	int operand1, operand2;
+	double operand1, operand2;
 	char operator = ' ';
-	int result, line = 0;
+	int line = 0;
+	double result = 0;
 
 	fp = fopen("read.txt","r");
 	if(fp!=NULL){
-		fscanf(fp, "%d", &line);
-
-		for(int i=0; i<line; i++) {
-			fscanf(fp, "%d %c %d",&operand1, &operator, &operand2);
-			switch(operator) {
-				case '+':
-				result = add(operand1, operator);
-				break;
-				case '-':
-				result = minus(operand1, operator);
-				break;
-				case '*':
-				result = mul(operand1, operator);
-				case '/':
-				result = div(operand1, operator);
-				break;
-			}		
-			printf("%d %c %d = %d\n",
-				 operand1, operator, operand2, result);
+		my_fscanf(fp, "%d", &line);
+		for(int i=1; i<line; i++) {
+			my_fscanf(fp, "%f %c %f",&operand1, &operator, &operand2);
+			result = calc(operand1, operand2, operator);
+			printf("%f %c %f = %f\n", operand1, operator, operand2, result);
 		}
 	}
 	return 0;

my_fscanf.c

@@ -0,0 +1,42 @@
+#include "my_fscanf.h"
+#include <stdarg.h>
+#include <ctype.h>
+
+void my_fscanf(FILE *fp, const char *format, ...) {
+	va_list list;
+	va_start(list, format);
+	while(*format) {
+		if(*format == '%') {
+			format++;
+			switch(*format) {
+			case 'd': {
+				int c = getc(fp);
+				int *pInt = va_arg(list, int*);
+				*pInt = c - '0';
+				break;
+			}
+			case 'f': {
+				int c = getc(fp);
+				while(isspace(c)) { c = getc(fp); }
+				double *pDouble = va_arg(list, double*);
+				double num = 0;
+				while(isdigit(c)) {
+					num = num*10 + c - '0';
+					c = getc(fp);
+				}
+				*pDouble = num;
+				break;
+			}
+			case 'c': {
+				char c = getc(fp);				
+				char *pChar = va_arg(list, char*);
+				*pChar = c;
+				break;
+			}			
+			}
+		}
+		else
+			format++;
+	}
+	va_end(list);
+}	

my_fscanf.h

@@ -0,0 +1,7 @@
+#ifndef MY_FSCANF_H
+#define MY_FSCANF_H
+#include <stdio.h>
+
+void my_fscanf(FILE *fp, const char *format, ...);
+
+#endif /* !MY_FSCANF_H */

operators.c

@@ -1,16 +1,15 @@
 #include "operators.h"
 
-int add(int op1, int op2) {
+double add(double op1, double op2) {
 	return op1+op2;
 }
-int minus(int op1, int op2) {
+double minus(double op1, double op2) {
 	return op1-op2;
 }
-int mul(int op1, int op2) {
+double mul(double op1, double op2) {
 	return op1*op2;
 }
-
-int div(int op1, int op2) {
-	return op1%op2;
+double div(double op1, double op2) {
+	return op1/op2;
 }
 

operators.h

@@ -1,4 +1,4 @@
-int add(int op1, int op2);
-int mul(int op1, int op2);
-int div(int op1, int op2);
-int minus(int op1, int op2);
+double add(double op1, double op2);
+double mul(double op1, double op2);
+double div(double op1, double op2);
+double minus(double op1, double op2);