I am trying to have a user input a part of a file name which will open the whole file.

e.g. the file name is Track P56.csv and i want to just be able to type in 56 when prompted to input a Track number.

This is how it is done currently however i have to type 'Track P56.csv' instead of just the number 56. Thank you in advance.

%User Input for Track Number
  tracknum = input("Track file name, Format: ('Track P__.csv'): ");
  
 
    
  %Opening the File  
  fid = fopen(tracknum,"r");

Answer 1

[Walter Roberson]

trackfile = "Track P" + tracknum + ".csv";
[fid, msg] = fopen(trackfile, "r");
if fid < 0
    error('Could not open file "%s" because "%s"', trackfile, msg);
end

[Jake]

Thank you

Answer 2

[Image Analyst]

Try this:

tracknum = input("Track file name, Format: ('Track P__.csv'): ");
folder = pwd; % Wherever you want.
fullFileName = fullfile(folder, sprintf('Track P%d.csv', tracknum));
%fid = fopen(fullFileName,"rt");
if isfile(fullFileName)
    % File exists so read in the data.
    data = readmatrix(fullFileName) % Read in the CSV file.
else
    % File does not exist.  Alert the user.
    errorMessage = sprintf('File not found: "%s"', fullFileName)
    uiwait(errordlg(errorMessage));
    return;
end

Better would be to load up the files into a listbox on a GUI and let the user click on the one they want.