`ferror`

Returns the error message and code of the last file operation.

Category: Data Import and Analysis > Data Import and Export

Syntax

msg = ferror(fid)

Returns the message text.

[msg, errnum] = ferror(fid)

Also returns a numeric error code.

Description

ferror reports the state of the file after the most recent input or output call. For a file that has been used without problems the message is empty and the code is 0. It is most useful right after a read or write that appeared to fail.

Input arguments

fid: File identifier from fopen.

Output arguments

msg: Error message, empty when there is no error.
errnum: Error code, 0 when there is no error.

Example

A healthy file

fid = fopen('e.txt', 'w');
fprintf(fid, 'x');
[msg, code] = ferror(fid)
fclose(fid);

Output

msg = 0×0 empty char array
code = 0

ferror