Did you read the UFFI chapter? https://ci.inria.fr/pharo-contribution/view/Books/job/PharoBookWorkInProgress/174/artifact/book-result/UnifiedFFI/UnifiedFFI.pdf
https://ci.inria.fr/pharo-contribution/view/Books/job/PharoBookWorkInProgress/174/artifact/book-result/UnifiedFFI/ I'm turning it into a booklet but I will not write it because I'm bad in FFI Now if you have corrections, suggestions, please do some pull requests https://github.com/SquareBracketAssociates/Booklet-uFFI Stef On Mon, May 22, 2017 at 10:42 PM, horrido <horrido.hobb...@gmail.com> wrote: > There is shockingly very little documentation on how to use uFFI. In > particular, I have the following situation... > > A shared C lib has the following function: > > void get_machine(char *machine) { > uname(&uname_s); > strcpy(machine, uname_s.machine); > } > > It copies the content of a string value into the buffer passed to it (char > *machine). > > I want to call this function from Pharo, thus: > > buffer := String new: 64. > self ffiCall: #( void get_machine(String buffer) ). > > The buffer never receives the string value (it just contains the 64 > initiialized spaces). > > Clearly, I'm misunderstanding the proper mechanism for doing this. > > [There are other functions in the shared C lib that work fine, such as: > > uint get_uptime() { > sysinfo(&info); > return info.uptime; > } > > Returning integers or floats is no problem. But passing arguments by > reference seems to be verboten.] > > > > -- > View this message in context: http://forum.world.st/How-to- > use-uFFI-with-String-tp4947890.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >
