fclose

Close one or all open files

Syntax

fclose(fileID)

fclose('all')

status = fclose(___)

Description

fclose(fileID) closes an open file.

fclose('all') closes all open files.

status = fclose(___) returns a status of 0 when the close operation is successful. Otherwise, it returns -1. You can use this syntax with any of the input arguments of the previous syntaxes.

Examples

Open and Close File

Open the badpoem.txt file, read the first line, and then close the file.

Use fopen to open the file. This function assigns a unique file id to use for reading and writing to the file.

fid = fopen('badpoem.txt')

fid = 
3

Read the first line from the file using fgetl.

fgetl(fid)

ans = 
'Oranges and lemons,'

Close the file.

fclose(fid);

Input Arguments

fileID — File identifier

integer

File identifier of an open file, specified as an integer. Before closing a file with fclose, you must use fopen to open the file and obtain its identifier fileID.

Data Types: double

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

Usage notes and limitations:

• The fclose('all') syntax is not supported in thread-based environments.

Version History

Introduced before R2006a

R2024b: Read data over HTTP and HTTPS using low-level file functions

You can read data from primary online sources by performing low-level file read operations over an internet URL.

R2022b: Use function in thread-based environments

This function supports thread-based environments.