Detect P-code

Is there a way for a function to query if it is running from an m-file or if it has been deployed as a p-file. The function "isdeployed()" returns zero for p-code. Is there anything equivalent to "ispcode()"?

Thanks

Ronan

[Daniel Shub]

Why would you want to know if you are running pcode?

Answer 1

[Paulo Silva]

Maybe this:

a=dbstack('-completenames');
if (isempty(strfind(a.file,'.m')))
disp('pcode')
else
disp('mfile')    
end

[Jan]

The '.m' can be a part of the path also.

[Paulo Silva]

Thanks Jan

a=dbstack('-completenames');

fend=a.file;

fend=fend(end-1:end);

if (strcmp(fend,'.m'))

disp('mfile')

elseif (strcmp(fend,'.p'))

disp('pcode')

else

disp('undefined')

end

[Jan]

See FEX: strncmpir :-)

This was developped exactly for this case. The "i" takes into account, that the file extension could be '.M' also.

Answer 2

[Jan]

If a P-file is found in the path, it is used.

isPCode = (exist(mfilename, 'file') == 6);

But this is not fast. The best idea would be to modify the source before P-coding:

isPcode = false;  % Toggled automatically

Then the P-coding:

fid = fopen(MFileName, 'r');
if fid < 0, error('Cannot open %s', MFileName); end
DataC = textscan(fid, '%s', 'delimiter', '\n');
fclose(fid);
Str = DataC{1};
Str = strrep(Str, 'isPcode = false;', 'isPcode = true;');

fid = fopen(MFileName, 'w');
if fid < 0, error('Cannot open %s', MFileName); end
fprintf(fid, '%s\n', Str{:});
fclose(fid);
pcode(MFileName, '-inplace');

And finally restore the original MFile again using DataC{1}. Unfortunately the modification date of the P-file is older than the M-file and a warning appears. This can be avoided either by setting the modification date of the P-file to a later time, or by saving the modified source to a temporary file only and call the builtin but undocumented _pwrite function, which allows to specify a different name for the P-file.

NOTE: I admit, this has an optimal runtime, but is not convenient.