How can I create a variable of type "voidPtr" which points to a string using the LIBPOINTER function in MATLAB?

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MathWorks Support Team 2011-12-5

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I have a function in a generic library which takes a string as input. The function, however, expects a void pointer. When I try to call the function using the CALLLIB function with a string as input, I get the following error:

 ??? Error using ==> calllib
 Array must be numeric or logical or a pointer to one.

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Answer 1

MathWorks Support Team 2011-12-5

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This enhancement has been incorporated into the documentation as of MATLAB 7.2 (R2006a). For previous product releases, read below for any possible workarounds:

In C, characters are represented as unsigned 8-bit integers. In order to create a variable of type "voidPtr" containing a string, the string must first be cast to one of this numeric type as in the following code:

p=libpointer('voidPtr',[ uint8('this is a string') 0]);

The data in the pointer can then be accessed: