How do you get the size of a file in MATLAB?

What is the best way to figure out the size of a file using MATLAB? The first thought that comes to mind is size(fread(fid)).


Please see the dir function as stated above.

Please note that the dir function works on files and not on directories only.

>> s = dir('c:\try.c')

s = 

       name: 'try.c'
       date: '01-Feb-2008 10:45:43'
      bytes: 20
      isdir: 0
    datenum: 7.3344e+005

You can use the DIR function to get directory information, which includes the sizes of the files in that directory. For example:

dirInfo = dir(dirName);  %# Where dirName is the directory name where the
                         %#   file is located
index = strcmp({},fileName);  %# Where fileName is the name of
                                          %#   the file.
fileSize = dirInfo(index).bytes;  %# The size of the file, in bytes

Or, since you are looking for only one file, you can do what Elazar said and just pass an absolute or relative path to your file to DIR:

fileInfo = dir('I:\kpe\matlab\temp.m');
fileSize = fileInfo.bytes;

Use the fact that MatLab has access to Java Objects:

myFile ='filename_here')
flen = length(myFile)

If you don't want to hardcode in your directory, you can use the built in pwd tool to find the current directory and then add your file name to it. See example below:

FileInfo = dir([pwd,'\tempfile.dat'])
FileSize = FileInfo.bytes

The question seems to indicate that fopen/fread/.. is used. In this case, why not seeking to the end of the file and reading the position?


function file_length = get_file_length(fid)
% extracts file length in bytes from a file opened by fopen
% fid is file handle returned from fopen

% store current seek
current_seek = ftell(fid);
% move to end
fseek(fid, 0, 1);
% read end position
file_length = ftell(fid);
% move to previous position
fseek(fid, current_seek, -1);


Matlab could have provided a shortcut..

More on ftell can be found here.

This code works for any file and directory (no need for absolute path) :

    index = strcmp({},[filename, '.ext']); % change the ext to proper extension 
    fileSize = dirInfo(index).bytes

Easy way to find size of file is: enter these cammands



and get size of file.

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