Reading Data From a File in C Programing

As we have seen in the earlier articles, to create a file and write information to a file, we can also read the stored data from a file. There are three different steps to read data from a file, they are:

fgetc(file_pointer): 

It returns the next character from the file pointed to by the file pointer. When the pointer reaches the end of the file the operation terminates.

fgets(buffer, n, file_pointer): 

It reads n-1 characters from the file and stores the string in a buffer in which a NULL character ‘\0’ is appended as the last character.

fscanf(file_pointer, conversion_specifiers, variable_adresses):

It is used to parse and analyze data. It reads characters from the file and assigns the input to a list of variable pointers variable addresses using conversion specifiers.

Let us see an example to get things cleared.

#include <stdio.h>
int main() {
        FILE *ptr;
        char str[30], c;
		//Using fgets()
        ptr = fopen("test.txt", "r");
        printf("Reading data using fgets()\n");
        fgets(str, 50, ptr);
        printf("%s\n", str);
		//Using fscanf()
        printf("Reading data using fscanf()\n");
        ptr = fopen("test.txt", "r");
        char str1[10], str2[20], str3[30], str4[40];
        fscanf(ptr, "%s %s %s %s", str1, str2, str3, str4);
        printf("%s\n", str1);
        printf("%s\n", str2);
        printf("%s\n", str3);
        printf("%s\n", str4);
		//Using getc()
        printf("\nReading the file using getc()\n");
        ptr = fopen("test.txt", "r");
        while ((c = getc(ptr)) != EOF) 
		printf("%c", c);
 
        fclose(ptr);
        return 0;
    }

Output:

Reading data using fgets()
Hi, Welcome To LingarajTechhub
Reading data using fscanf()
Hi,
Welcome
To
LingarajTechhub