read name and password from a file in c - c

Question

I am trying to read name and password from a file into a structure in c, but clearly my code does not work as expected. Is there anyone can help me to figure out the problem with the codes attached below? Thanks a lot!
(Basically the file has several names and passwords, and I want to read them into a structure accounts[]`)
#include <stdio.h>
#include <stdlib.h>
struct account {
char *id;
char *password;
};
static struct account accounts[10];
void read_file(struct account accounts[])
{
FILE *fp;
int i=0; // count how many lines are in the file
int c;
fp=fopen("name_pass.txt", "r");
while(!feof(fp)) {
c=fgetc(fp);
if(c=='\n')
++i;
}
int j=0;
// read each line and put into accounts
while(j!=i-1) {
fscanf(fp, "%s %s", accounts[j].id, accounts[j].password);
++j;
}
}
int main()
{
read_file(accounts);
// check if it works or not
printf("%s, %s, %s, %s\n",
accounts[0].id, accounts[0].password,
accounts[1].id, accounts[1].password);
return 0;
}
and the name_pass.txt file is a simple file like this (name+password):
hello 1234
lol 123
world 123

Answer 1

You are reading file two times. So you need to fseek(), or rewind() to first char before second loop starts.
try with:
fseek(fp, 0, SEEK_SET); // same as rewind()
or
rewind(fp); // s
this code you need to add between two loops (after first and before second loop)
Additionally, you are to allocate memory for id, password filed in account struct:
struct account {
char *id;
char *password;
};
or do allocate memory statically as #Adrián López suggested in his answer.
EDIT I corrected you code:
struct account {
char id[20];
char password[20];
};
static struct account accounts[10];
void read_file(struct account accounts[])
{
FILE *fp;
int i=0; // count how many lines are in the file
int c;
fp=fopen("name_pass.txt", "r");
while(!feof(fp)) {
c=fgetc(fp);
if(c=='\n')
++i;
}
int j=0;
rewind(fp); // Line I added
// read each line and put into accounts
while(j!=i-1) {
fscanf(fp, "%s %s", accounts[j].id, accounts[j].password);
++j;
}
}
int main()
{
read_file(accounts);
// check if it works or not
printf("%s, %s, %s, %s\n",
accounts[0].id, accounts[0].password,
accounts[1].id, accounts[1].password);
return 0;
}
and its working as follows:
:~$ cat name_pass.txt
hello 1234
lol 123
world 123
:~$ ./a.out
hello, 1234, lol, 123

Answer 2

You need to malloc() the content of the pointers in your struct or declaring then with an static size:
struct account {
char id[20];
char password[20];
};

Answer 3

You should probably first allocate memory for the stuff you're scanfing in. Keyword is malloc, a bit too long to lecture right here.