Problem with scanf/gets in C file handling [duplicate] - c

Question

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scanf() leaves the newline character in the buffer
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Whenever I run this code, final scanf function to get 'email' input does not execute and I get 'Updated successfully!' message directly! I tried using gets() instead of scanf and I'm getting the same problem. Can someone please explain the problem to me?
The Image of the Output
#include <stdio.h>
#include <stdlib.h>
typedef struct Directory
{
char name[20], email[20];
long int phone;
}Directory;
void add()
{
Directory d;
FILE *file;
file = fopen("phonebook.bin", "ab");
if(!file)
printf("Failed to open file!");
else
{
printf("Enter the name: ");
scanf("%[^\n]", &d.name);
printf("Enter the Phone Number: ");
scanf("%ld", &d.phone);
printf("Enter the e-mail ID: ");
scanf("%[^\n]", &d.email);
if(fwrite(&d, sizeof(Directory), 1, file))
printf("Updated successfully!");
else
printf("Something went wrong, Please try again!");
}
fclose(file);
}
int main()
{
add();
}

Answer 1

There are multiple problems in your code.
Correct format for char array is '%s'. I really don't know what is '%[^\n]'.
You get memory corruption for sending the address of the char array in scanf(). The name of the array is actually a const pointer to the start of the array.
For example :
char a[10]; // a is somewhat equivalent to &a[0].
In your example scanf() needs an address for its second argument and the name of the array already is an address; an address to the first element of the array.
Your code should look like this:
void add()
{
Directory d;
FILE* file;
file = fopen("phonebook.bin", "ab");
if (!file)
printf("Failed to open file!");
else
{
printf("Enter the name: ");
scanf("%s", d.name); // ---> notice the %s format and the missing &
printf("Enter the Phone Number: ");
scanf("%ld", &d.phone);
printf("Enter the e-mail ID: ");
scanf("%s", d.email); // ---> same here
if (fwrite(&d, sizeof(Directory), 1, file))
printf("Updated successfully!");
else
printf("Something went wrong, Please try again!");
}
fclose(file);
}
By doing &d.email in scanf you will crash or get undefined behavior.
Please put in some effort in research before posting.