MathGroup Archive 2002

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Help needed regarding function MLOpenString

  • To: mathgroup at
  • Subject: [mg33333] Re: [mg33324] Help needed regarding function MLOpenString
  • From: John Fultz <jfultz at>
  • Date: Sat, 16 Mar 2002 01:40:11 -0500 (EST)
  • References: <>
  • Sender: owner-wri-mathgroup at

There's some ambiguity in the call to MLOpenString.  You're passing...
-linkname 'c:\\program files\\wolfram 
research\\mathematica\\3.0\\mathkernel' -mathlink

This doesn't clearly indicate that the kernel should be passed the 
-mathlink argument (-mathlink might very well be parsed as another 
argument from the string instead of part of the linkname argument).  If 
you put it inside the quotes, it becomes less ambiguous, in that sense, 
but more in another...which spaces are spaces in the filename and which 
are spaces delimit the command-line arguments to the program.

A precise way to address the issue is to use MLOpenArgv().  Here's an 
example of how you would use it...

MLEnvironment ep = MLInitialize( (MLParametersPointer)0);
char * argv[4];
long errorCode;

argv[0] = "-linklaunch";
argv[1] = "-linkname"
argv[2] = "\"C:\\Program Files\\Wolfram 
Research\\Mathematica\\4.1\\MathKernel\" -mathlink"
argv[3] = "";

lp = MLOpenArgv(ep, argv, argv + 3, &errorCode);


John Fultz
jfultz at
User Interface Group
Wolfram Research, Inc.

On Thu, 14 Mar 2002 19:51:27 -0500 (EST), akash gupta wrote:
>We have this application which uses MathLink. It runs
>perfectly fine with version 4.0 but hangs with the
>version 4.1.
>The function that hangs is MLOPenString()
>Can you please help me with this. I went through the
>online documentation but it seems there is no change
>in this function in the two versions. Therefore cannot
>figure out why one works and the other not.
>Akash Gupta
>The code is something like this
>ep =  MLInitialize( (MLParametersPointer)0);
>if( ep == (MLENV)0) return(OpenMathLinkError);
>atexit( deinit);
>"-linkname 'c:\\program files\\wolfram
>research\\mathematica\\3.0\\mathkernel' -mathlink",
>InitString, 254, "QRAS.INI");
>Two values of InitString are
>For 4.0
>InitString=-linkname 'c:\Program Files\Wolfram
>Research\Mathematica\4.1\Mathkernel.exe' -mathlink
>For 4.1
>InitString=-linkname 'c:\Program Files\Wolfram
>Research\Mathematica\4.0\Mathkernel.exe' -mathlink

  • Prev by Date: Re: Can anyone help about this inverse laplacetransform problem?
  • Next by Date: Re: Can anyone help about this inverse laplacetransform problem?
  • Previous by thread: Help needed regarding function MLOpenString
  • Next by thread: Release of Analog Insydes 2.0