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.