Re: libapl stdout

[Chris Moller]

    For what it's worth, in an ongoing project in use:
    
      
> #include
>         <QtWidgets>
>         
>         
>         #include <iostream>
>         
>         #include <sstream>
>         
>         
>         #include <apl/libapl.h>
>         
>         
>         #include "aplexec.h"
>         
>         
>         LIBAPL_error
>         
>         AplExec::aplExec (apl_op_e apl_op, QString &cmd,
>         
>                   QString &outString, QString &errString)
>         
>         {
>         
>          LIBAPL_error execerr = LAE_NO_ERROR;
>         
>         
>          switch(apl_op) {
>         
>          case APL_OP_EXEC:
>         
>            {
>         
>              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 ());
>         
>            }
>         
>            break;
>         
>          case APL_OP_COMMAND:
>         
>            {
>         
>              std::stringstream errbuffer;
>         
>              std::streambuf *cerrbuf = std::cerr.rdbuf();
>         
>              std::cerr.rdbuf(errbuffer.rdbuf());
>         
>              const char *res = apl_command (cmd.toStdString ().c_str
>         ());
>         
>              if (res) {
>         
>                outString = QString (res);
>         
>                free ((void *)res);
>         
>              }
>         
>              std::cerr.rdbuf(cerrbuf);
>         
>              errString = QString (errbuffer.str ().c_str ());
>         
>            }
>         
>            break;
>         
>          }
>         
>         
>          return execerr;
>         
>         }
>       
>         
>       
    I.e., I'm capturing stdout and stderr in strings.

On 1/27/23 10:18, Dr. Jürgen Sauermann wrote:

> Hi
>       enztec,
>       
>       
>       not sure if this helps, but if I remember correctly (I may not)
>       then the main GNU APL output
>       
>       goes to *stderr* (fd 2) and not to *stdout* (fd 1). The reason is
>       somewhat historic because *stdout* is
>       
>       buffered by default while *stderr* is not (which caused some
>       issues with *stdout* when used
>       
>       interactively that did not occur with *stderr*).
>       
>       
>       Best Regads,
>       
>       Jürgen
>       
>       
>       
>       On 1/15/23 12:19 AM, enztec@gmx.com wrote:
>       
> > Hi
> >         
> >         
> >         I'm still trying to resolve the failure of fpc using libapl to
> >         get it's stdout
> >         
> >         
> >         trying to get libapl stdout to be gotten in my libapl/fpc
> >         program i read the
> >         
> > https://gist.github.com/houmei/cfd9e570b8de4d8fd55ada228d5ff004#file-readme-2-configure
> >         
> >         
> >         thinking fpc might be using a different stdout then the libapl
> >         does from this line
> >         
> >         'but because the executable that is linked with libapl.so) has
> >         its own I/O channels.'
> >         
> >         
> >         and re-compiled libapl with --with-android
> >         
> >         and then compiling my program i get get :
> >         
> >         
> >         /usr/local/lib/apl/libapl.so: undefined reference to `CIN'
> >         
> >         /usr/local/lib/apl/libapl.so: undefined reference to `UERR'
> >         
> >         /usr/local/lib/apl/libapl.so: undefined reference to `COUT'
> >         
> >         /usr/local/lib/apl/libapl.so: undefined reference to `CERR'
> >         
> >         
> >         is this suppose to happen ?
> >         
> >         
> >         i get same error when compiling my libaplo.c program
> >         
> >         
> >         how to set these in the c program?
> >         
> >         
> >         
> >       
>       
>       
>

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