lab14

calc.c

@@ -1,35 +1,36 @@
 #include <stdio.h>
 #include "operators.h"
-
+#include "my_fscanf.h"
 int main(){
 	FILE *fp = NULL;
-	int operand1, operand2;
+	int operand1, operand2,line=0;
 	char operator = ' ';
-	int result, line = 0;
-
+	double result;
+	double (*function_p) (int ,int );
+
 	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);
+		my_fscanf(fp, "%d", &line);
+		for(int i=0; i<line && !feof(fp); i++) {
+			my_fscanf(fp, "%d %c %d",&operand1, &operator, &operand2);
 			switch(operator) {
 				case '+':
-				result = add(operand1, operator);
+				function_p = add;
 				break;
 				case '-':
-				result = minus(operand1, operator);
+				function_p = minus;
 				break;
 				case '*':
-				result = mul(operand1, operator);
+				function_p = mul;
+				break;
 				case '/':
-				result = div(operand1, operator);
+				function_p = div;
 				break;
-			}		
-			printf("%d %c %d = %d\n",
-				 operand1, operator, operand2, result);
+			}
+			result = function_p(operand1,operand2);
+			printf("%d %c %d = %f\n",
+				operand1, operator, operand2, result);
 		}
 	}
 	return 0;
 }
-

my_fscanf.c

@@ -0,0 +1,40 @@
+#include "my_fscanf.h"
+#include <stdarg.h>
+#include <ctype.h>
+#include <stdio.h>
+void my_fscanf(FILE *fp, const char *format, ...) {
+	va_list list;
+	va_start(list, format);
+	char* cc;
+	while (*format) {
+		if (*format == '%') {
+			format++;
+			int c,*_num;
+			switch(*format) {
+			case 'd':
+				while(isspace(c = getc(fp))) {}
+				_num = va_arg(list, int*);
+				unsigned int num = 0;
+				while (isdigit(c)) {
+					num = num * 10 + c - '0';
+					c = getc(fp);
+				}
+				*_num = num;
+				while(isspace(c = getc(fp))) {}
+				ungetc(c,fp);
+				break;
+			case 'c' :
+				cc = va_arg(list, char*);
+				c = getc(fp);
+				*cc =c;
+				while(isspace(c = getc(fp))) {}
+				ungetc(c,fp);
+				break;
+			}
+		}
+		else
+			format++;
+	}
+		va_end(list);
+
+}

my_fscanf.h

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