fseek() vs rewind() in C

The fseek() and rewind() functions are used to reposition the file pointer in a file stream. While both can move the pointer to the beginning of a file, they differ in flexibility, error handling, and usage.

• fseek() moves the file pointer to any specified location.
• rewind() resets the file pointer to the beginning of the file.
• Both functions are declared in the <stdio.h> header file.

fseek()

The fseek() function repositions the file pointer relative to the beginning, current position, or end of a file.

• Supports random file access.
• Can move forward or backward.
• Returns a status value for error checking.

Example: The following program moves the file pointer back to the beginning using fseek().

#include <stdio.h>

int main()
{
    FILE *fp = fopen("test.txt", "r");

    if (fp == NULL)
        return 1;

    // Move to the beginning of the file
    if (fseek(fp, 0, SEEK_SET) == 0)
        printf("File pointer repositioned successfully.");

    fclose(fp);

    return 0;
}

Output

File pointer repositioned successfully.

Explanation: The fseek() function moves the file pointer to the beginning of the file. Its return value can be checked to determine whether the operation was successful.

rewind()

The rewind() function resets the file pointer to the beginning of the file.

• Moves the pointer to the beginning only.
• Clears the file error and EOF indicators.
• Does not provide a return value.

Example: The following example resets the file pointer to the beginning using rewind().

#include <stdio.h>

int main()
{
    FILE *fp = fopen("test.txt", "r");

    if (fp == NULL)
        return 1;

    // Reset the file pointer
    rewind(fp);

    printf("File pointer reset to the beginning.");

    fclose(fp);

    return 0;
}

Output

File pointer reset to the beginning.

Explanation: The rewind() function resets the file pointer to the beginning of the file. Unlike fseek(), it does not return a value, so its success cannot be checked directly.

fseek() Vs rewind()