Re: libapl apl_exec results displayed as ?

[Dr . Jürgen Sauermann]

    Hi again,
      
      just realized that there is a nice "info libapl" written by Dr.
      Dirk Laurie
      (the author of libapl) which explains the callback in section 2.4.
      
      Best Regards,
      Jürgen

On 7/25/22 11:28 AM, Dr. Jürgen Sauermann wrote:

Hi enztec,

not entirely sure since I haven't written libapl myself. However, looking
at the code it seems to me as if apl_exec returns an APL error code (most
likely as per Error.def) if it fails.

To capture the APL result I suppose you have to print in the _expression_ or
install a result_callback (just guessing), see API description in libapl.h

BTW the libapl API is C while GNU APL is C++.

Best Regards,
Jürgen

On 7/24/22 11:49 PM, enztec@gmx.com wrote:

Hi

i can see you code is c++

I am working with libapl with fpc (freepascal) and i can capture stdout and stderr fine in fpc coding
but the only stdout i get from ap_exec is the 0

i have apl_exec as a function and tried with either of the following definitions

function apl_exec(p : pchar) : longint; cdecl; // gives good results displayed but stdout captures only 0

function apl_exec(p : pchar) : ansistring; cdecl; // gives nothing to screen with apl_exec nor any stdout





On Sun, 24 Jul 2022 17:16:10 -0400

Chris Moller <moller@mollerware.com> wrote:

apl_exec() can output to both stdout and stderr.

I use:


std::stringstream outbuffer;
      std::streambuf *coutbuf = std::cout.rdbuf();
      std::cout.rdbuf(outbuffer.rdbuf());
      std::stringstream errbuffer;
      std::streambuf *cerrbuf = std::cerr.rdbuf();
      std::cerr.rdbuf(errbuffer.rdbuf());
      execerr = apl_exec (cmd.toStdString ().c_str ());
      std::cout.rdbuf(coutbuf);
      std::cerr.rdbuf(cerrbuf);
      outString = QString (outbuffer.str ().c_str ());
      errString = QString (errbuffer.str ().c_str ());

On 7/24/22 16:12, enztec@gmx.com wrote:

hello

What does libapl output?- the apl_exec function returns 0 to stdout but what is the actual display?

for example  apl_exec('⍳20')  what/where is the 1 to 20 displayed so it can be captured?

thanks