C program to compare two files line by line

Write a C program to compare two files line by line.

  #include <stdio.h>
  #include <string.h>
  #define MAX 256

  int main() {
        FILE *fp1, *fp2;
        char file1[MAX], file2[MAX];
        char fline[MAX], sline[MAX];

        /* get the first input file name from the user */
        printf("Enter your first file name:");
        scanf("%s", file1);

        /* get the second input file name from the user */
        printf("Enter your second file name:");
        scanf("%s", file2);

        /* open the first file in read mode */
        fp1 = fopen(file1, "r");

        /* error handling */
        if (!fp1) {
                printf("Unable to open the first input file!!\n");
                return 0;
        }

        /* open the second input file in read mode */
        fp2 = fopen(file2, "r");

        /* error handling */
        if (!fp2) {
                printf("Unable to open the second input file!!\n");
                fclose(fp1);
                return 0;
        }

        /* comparing two files line by line */

        while ((!feof(fp1)) || (!feof(fp2))) {

                fgets(fline, MAX, fp1);

                fgets(sline, MAX, fp2);

                /* if both the file contents are not equal */

                if (strcmp(fline, sline) != 0) {

                        printf("Given two files are not identical!!\n");

                        fclose(fp1);

                        fclose(fp2);

                        return 0;

                }

        }

        /* file contents in both files are same */

        printf("Given two file have identical contents!!\n");

        /* close the opened files */

        fclose(fp1);

        fclose(fp2);

        return 0;

  }

  Output:

  jp@jp-VirtualBox:~/$ cat first.txt 
  abcdefghij
  0123456789
  abcdefghij
  0123456789
  abcdefghij
  0123456789

  jp@jp-VirtualBox:~/$ cat second.txt 
  0123456789
  abcdefghij
  0123456789
  abcdefghij
  0123456789

  jp@jp-VirtualBox:~/$ ./a.out
  Enter your first file name:first.txt
  Enter your second file name:second.txt
  Given two files are not identical!!

SEE ALSO

---

• c program to write a string into a file
• c program to read numbers from a file and write even, odd and prime numbers in separate files
• c program to create a file and store "hello world" in it
• c program to read the contents of the given file
• c program to delete all blank lines in a file
• c program to check whether a directory exists or not
• c program to check whether a file exists or not
• c program to copy a file from one location to another
• c program to create, read, edit and close a file
• c program to create a file with input content
• c program to read a file line by line
• c program to compare two files character by character
• c program to concatenate two files
• c program to convert lowercase characters in a file to uppercase
• c program to convert uppercase characters in a file to lowercase
• c program to list all files in a directory
• c program to list all files in a directory recursively
• c program to append data into a file
• c program to count number of lines in a file
• c program to delete a file or directory
• c program to print the source code of itself as output
• c program to convert the contents in a file from lowercase to uppercase and vice versa
• c program to merge two files
• c program to move a file to different location
• c program to replace articles with space in a text file
• c program to print the words in a file starting with the given character
• c program to delete given word in a file
• c program to replace a word in a file
• c program to merge alternate lines from two files
• c program to remove numbers in a file
• c program to check end of file
• c program to compare two files line by line
• c program to delete specific line from a file
• c program to replace specific line in a file
• c program to take input from a file
• c program to delete a record from a file
• c program to find the number of character, words and lines in a file
• c program to sort characters in each words of a file
• c program to convert text file to binary
• c program to split a file to multiple files
• c program to find the file type, permission, size and last modification date of the given file
• c program to encrypt and decrypt contents of a file
• c program to eliminate comments from a file