How do I pass a filename to a routine in Matlab's command window?

In the Matlab Command window I would like to run a function with an input parameter, like this:

>> xxxreplace oldGEOPLOT

s = 

    "./html/oldGEOPLOT.html"

Error using fread
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in xxxreplace (line 14)
ff=fread(fid,'*char')';

I'm using this code :

function file=xxxreplace(x)
f=string(x);
s=strcat('./html/',f,'.html')
fid=fopen(s,'r');
ff=fread(fid,'*char')';
fclose(fid);
ff =strrep(ff,'.png" alt="">','.png" alt="" width="360">');
fid=fopen('./html/new.html','w');
fprintf(fid,'%s',ff);
fclose(fid);
disp(s)
end

Why do I get this error?

Thanks a lot,

Harry

[Matt J]

Perhaps the file doesn't exist? Or you don't have permission to open it?

The point is, the error is caused by the status of the file, which we your audience have no way of knowing.

[Harald von der Osten]

Oh, I should have mentioned, that if I use this:

fid=fopen('./html/oldGEOPLOT.html','r');
f=fread(fid,'*char')';
fclose(fid);
f =strrep(f,'.png" alt="">','.png" alt="" width="360">');
fid=fopen('./html/new.html','w');
fprintf(fid,'%s',f);
fclose(fid);

as normal Matlab script, there is no problem. But I would like to use this as a function and 'more universel'

[Matt J]

Is the Current Folder the same in both cases?

[Harald von der Osten]

yes

Answer 1

[Jan]

The error message is clear: The file does not exist. Although you assume, that the current folder is the same, this is not true. Check this explicitly:

function file = xxxreplace(x)   % What is "file"?
s = fullfile('./html/', [x, '.html']);
[fid, msg] = fopen(s, 'r');
assert(fid > 0, msg);
ff = fread(fid,'*char')';
fclose(fid);
ff  = strrep(ff,'.png" alt="">','.png" alt="" width="360">');
[fid, msg] = fopen('./html/new.html', 'w');
assert(fid > 0, msg);
fprintf(fid, '%s', ff);
fclose(fid);
end

Trusting on the current folder is a bad programming practice. Any timer or gui callback might change the current folder unexpectedly. Prefer to use absolute file names.

[Image Analyst]

And f is...? Do you mean x?

[Harald von der Osten]

thanks for your help. Hmmm...the file really exist:

[Harald von der Osten]

hey, now it works:

changing

s = fullfile('./html/', [f, '.html']);

to

s = fullfile('./html/', [x, '.html']);

made obviously the job. Thanks to all who helped me !!