How to check files in a specified directory through Simulink?

I'd like to detect the availability of a file in the simulation of a Simulink model, but I cannot find a working function for this.

I'm using a MATLAB script which detects the availability of a file in a specified directory, like './Data/'. This script makes use of the function

exist(f{n}, 'file')

, but I've also tried

isfile(f{n})

, and a less convenient solution using dir as

fileinfo 	= dir(out);
any(ismember({fileinfo.name}.', f{n}))

In these options f{n} either represents only the filename, or the filename including the path, depending on the chosen method. Out specifies the path.

In MATLAB each of these methods provides the desired results. However, when this is put in a MATLAB Function Block in Simulink, these functions are not compatible for code generation. Is there any function which has this functionality in Simulink, or is there a workaround? The solution must be compatible with code generation.

Answer 1

[Mark McBroom]

As long as you don't need to generate C code from your SImulink model, use the coder.extrinsic function to notify Simulink that you don't need to geneate simulation code for the unsupported function.

https://www.mathworks.com/help/simulink/slref/coder.extrinsic.html

[Oswin Hulsebos]

Eventually C code would need to be generated. I did see some C functions providing this functionality, and I believe I've also read something about being able to use C in Simulink. Preferably I wouldn't go that route, as I do not have much experience on that subject yet. However, if there's no other option within Simulink's functions I guess that'll be the way to go.