C Exercises: Read an existing file

Last update on August 08 2025 12:53:11 (UTC/GMT +8 hours)

2. Read Existing File

Write a program in C to read an existing file.

Sample Solution:

C Code:

#include <stdio.h>
#include <stdlib.h>

void main()
{
	FILE *fptr;
	char fname[20];
	char str;
    printf("\n\n Read an existing file :\n");
	printf("------------------------------\n"); 
	printf(" Input the filename to be opened : ");
	scanf("%s",fname);
	fptr = fopen (fname, "r");  
	if (fptr == NULL)
	{
		printf(" File does not exist or cannot be opened.\n");
		exit(0);
	}
	printf("\n The content of the file %s is  :\n",fname);
	str = fgetc(fptr);
	while (str != EOF)
		{
			printf ("%c", str);
			str = fgetc(fptr);
		}
	fclose(fptr);
    printf("\n\n");
}

Sample Output:

 Read and existing file :                                                                                     
------------------------------                                                                                
 Input the filename to be opened : test.txt                                                                   
                                                                                                              
 The content of the file test.txt is  :                                                                       
This is the content of the file test.txt

Flowchart:

For more Practice: Solve these Related Problems:

Write a C program to read a text file and display its content in reverse order (line by line).
Write a C program to read a file and count the occurrence of a specific keyword provided by the user.
Write a C program to read a file and print only the lines that contain a given substring.
Write a C program to read a file and output its content to the console along with the line numbers.

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C Programming Code Editor:

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