Development Environment

Closing a File

When you finish reading or writing, use fclose to close the file. For example, this line closes the file associated with file identifier fid.

• status = fclose(fid);
  

This line closes all open files.

• status = fclose('all'); 
  

Both forms return 0 if the file or files were successfully closed or -1 if the attempt was unsuccessful.

MATLAB automatically closes all open files when you exit from MATLAB. It is still good practice, however, to close a file explicitly with fclose when you are finished using it. Not doing so can unnecessarily drain system resources.

Note    Closing a file does not clear the file identifier variable fid. However, subsequent attempts to access a file through this file identifier variable will not work.

Writing Formatted Text Files

Exchanging Files with the Internet