I have eg a file J:\temp\maple\q.txt with these lines:

1+1;
f:=proc(x)
x^2;
end proc;

f(a);

and both

read "j:/temp/maple/q.txt";

or

read `j:/temp/maple/q.txt`;

produce this output:

                                  2
                      f := proc(x) x^2 end proc
                                   2
                                  a

As an alternative, eg if I have a txt file with prompts, J:\temp\maple\q2.txt say, with lines:

> 1+1;
> f:=proc(x)
> x^2;
> end proc;
>
> f(a);

I can do, from the Classic GUI menu, File > Open > Type: Maple Text , select q2.txt , Text Format Choice > Maple Text, and a worksheet q2.txt opens with the above lines.

In Standard GUI, similarly, File > Open > Files of type: Text (.txt), select q2.txt, Open > Maple Text (in Text Format Choice).

Alternatively, in Standard GUI, File > Open > Files of type: Text (.txt), select q.txt, Open > Maple Input (in Text Format Choice), and I get a worksheet q.txt with those same input lines (ie from a txt file without ">"s).

One thing to try is this:

If the file is named

"file.txt"  then try renaming it "file.mw" or maybe "file.mws". Next try to open it with Maple like any other mw file.

I often see students change the extension of their Maple files to .txt because our email system blocks files with extension .mw. They email the file with the txt extension, save it, then change the name back to mw.