fclose() in C

In C Language, the "fclose()" function is used to close a file stream that was previously opened using "fopen()" or a similar function from the standard I/O library "stdio.h".

Closing the file stream is important for releasing system resources and ensuring that any pending data is written to the file.

Overview of fclose() in C

Closing File Streams: `fclose()` is used to close a file stream, which releases the resources associated with the file and flushes any buffered data to the disk.
Error Handling: If an error occurs while closing the file, we can use `ferror()` function to check for errors.
Return Value: The `fclose()` function returns zero on success and EOF (End of File) on failure.

Features of fclose() in C:

File Cleanup: Closing files with `fclose()` ensures proper cleanup of resources and prevents memory leaks.
Buffer Flushing: Buffered data not written to the file is flushed to disk when `fclose()` is called, ensuring data integrity.

Syntax:

#include <stdio.h>

int fclose(FILE *stream);

Example:

stream: This is a pointer to the file stream that we want to close.

fclose() function Example:

#include <stdio.h>

int main() {
    FILE *fp;

    // Open a file for writing
    fp = fopen("example.txt", "w");

    if (fp == NULL) {
        printf("Error opening the file.\n");
        return 1;
    }

    // Write some data to the file
    fprintf(fp, "This is a test file.\n");

    // Close the file stream
    if (fclose(fp) != 0) {
        printf("Error closing the file.\n");
        return 1;
    }

    return 0;
}

We open a file named "example.txt" for writing using "fopen()".
Data is written to the file using "fprintf()".
Finally, we close the file stream using "fclose()". The return value of "fclose()" is checked to handle any errors that might occur during the closing process.

Note:

Always remember to close files after we finish using them to release resources properly.

Not closing files can lead to resource leaks and potential data loss.

<-- fopen()

fprintf() -->