C - Price look-up program - c

Question

I was asked to make a C program that act as a 'price lookup' where a user enter a product name and the program will print it's name and price which is stored in a file. If the item is not present in the file, the program will let the user know. The program will keep looping as long as the user wants to search. I did the coding using Dev C++, however after i run the code, the program got stuck after a few loops, and it's random. Could you guys detect any problem with my coding, or is it just the problem with Dev C++? I include my code below. Your help is greatly appreciated.
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<conio.h>
#include<ctype.h>
int main()
{
FILE *items;
char *mode="r";
char pName[50];
float pPrice;
char p1Name[50];
int value=0;
char respond='Y';
char s[50];
items=fopen("Product_Name_Price.txt", mode);
if(items==NULL)
{
fprintf(stderr, "Can't open file Product_Name_Price.txt!\n");
exit(1);
}
printf("File has been successfully opened\n");
do
{
printf("Enter the name of the product you wish to look for\n");
scanf("%s", &p1Name);
while(strcmp(p1Name, pName) !=0)
{
fscanf(items,"%s %f", pName, &pPrice);
//printf("%s\t%.2f\n", pName, pPrice);
//value=strcmp(p1Name, pName);
if(strcmp(p1Name, pName) == 0)
{
printf("%s\t%.2f\n", pName, pPrice);
}
}
/*
else
{
printf("No data in system\n");
}
*/
printf("Do you wish to look up for more item? (Y/N)\n");
scanf("%s", &respond);
}while(respond=='Y'|| respond=='y');
printf("This program is closing\n");
fclose(items);
}

Answer 1

Your program has undefined behaviour because your scanf("%s", &response) reads into response as if it were an array of sufficient size for the string being read — that size is at least 2 (including null terminator), but response is just one character. You blew up your stack and corrupted memory and then all bets are off.
You could write scanf("%c", &response) instead to actually read a single character, though you'd be better off switching to modern, safer tools if you're writing a C++ program.