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rewind() function in C language with Example

Here, we are going to learn about the rewind() function of library function stdio.h in C language with its syntax, example.
Submitted by Souvik Saha, on February 28, 2019

rewind() function in C

The rewind() function is defined in the <stdio.h> header file.

Prototype:

    void rewind(FILE *filename);

Parameters: FILE *filename

Return type: void

Use of function:

When we are dealing with files then sometimes we need to start of the specified files. In file handling, we use rewind() function to move the file position indicator to start of the specified file stream. The prototype of the function rewind() is void rewind(FILE *filename);

Here, filename is the name of the file where the file indicator starts. By the function, end-of-file and error flag is cleared.

rewind() example in C

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

int main()
{
    //Initialize the file pointer
    FILE* f;
    char ch[100];

    //Create the file for write operation
    f = fopen("includehelp.txt", "w");
    printf("Enter five strings\n");
    for (int i = 0; i < 4; i++) {
        //take the strings from the users
        scanf("%[^\n]", &ch);
        //write back to the file
        fputs(ch, f);
        //every time take a new line for the new entry string
        //except for last entry.Otherwise print the last line twice
        fputs("\n", f);

        //clear the stdin stream buffer
        fflush(stdin);
    }
    //take the strings from the users
    scanf("%[^\n]", &ch);
    fputs(ch, f);
    //close the file after write operation is over
    fclose(f);

    //open a file
    f = fopen("includehelp.txt", "r");
    printf("\n...............print the strings..............\n");
    while (!feof(f)) {
        //takes the first 100 character in the character array
        fgets(ch, 100, f);
        //and print the strings
        printf("%s", ch);
    }
    rewind(f);
    printf("\n...............print the strings again..............\n");
    while (!feof(f)) {
        fgets(ch, 100, f);
        printf("%s", ch);
    }

    //close the file
    fclose(f);

    return 0;
}

Output