Dynamic filepath for sftp not allowed

Home="/folder1/folder2";
Scanname="Exp04_Sample1";
Sftp_path=strcat(Home,"/",Scanname);
fileInfo=dir(s,Sftp_path);

Why does the above not work?

But

fileInfo=dir(s,"/folder1/folder2/Exp04_Sample1");

will work?

[Manas Shivakumar]

Can you describe the variable 's' ? specifically its purpose and its type. I couldn't find MATLAB's dir() function supporting a signature like this dir(var_a, var_b). List folder contents - MATLAB dir - MathWorks India

Answer 1

[Adam Danz]

The question is refering to the dir function for SFTP or FTP servers.

https://www.mathworks.com/help/matlab/ref/matlab.io.sftp.sftp.dir.html

I see no reason why the OP's two versions should not behave the same. If this happens again, please report it to tech support.

Home="/folder1/folder2";
Scanname="Exp04_Sample1";
Sftp_path=strcat(Home,"/",Scanname);

full = "/folder1/folder2/Exp04_Sample1"; 

isequal(Sftp_path, full)

ans = logical
   1

Note that using fullfile is better than manually constructing file paths.

Sftp_path = fullfile(Home,Scanname)

Sftp_path = "/folder1/folder2/Exp04_Sample1"

Answer 2

[Vatsal]

Hi,

The issue seems to be with the 'dir' function. The 'dir' function in MATLAB is used to list files and folders in a directory. When you use 'dir' with a variable as an argument, MATLAB expects the variable to be a string that specifies the name of the file or folder. If the variable is not a string or if the string does not represent a valid file or folder name, 'dir' will not work as expected. In the provided code, 's' and 'Sftp_path' are variables. If 's' is not defined in your code or does not represent a valid file or folder name, the 'dir' function will not work. Similarly, if 'Sftp_path' does not represent a valid file or folder name, the 'dir' function will not work.

I have attached a modified code below:

Home = '/folder1/folder2'; 

Scanname = 'Exp04_Sample1'; 

Sftp_path = fullfile(Home, Scanname); 

fileInfo = dir(Sftp_path); 

In this code, 'fullfile' is used instead of 'strcat' to construct the file path. 'fullfile' constructs a full file specification from the specified folder and file names. It is generally a better choice for constructing file paths because it automatically handles the file separators.

To learn more about the usage and syntax of 'dir' and 'fullfile', you may refer to the MathWorks documentation links below:

https://in.mathworks.com/help/matlab/ref/dir.html

https://in.mathworks.com/help/matlab/ref/fullfile.html

I hope this helps!