----- Original Message ----- From: "Craig Graham" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, June 07, 2004 3:25 AM Subject: Call Library
... > This is on Linux, if it's relevant. I have a library with a function whose > prototype (from the header file) is; > const char *gpgme_check_version (const char *req_version); > > This function returns a string and takes either a string or null, depending > on how you want it to work. For simplicity I'm passing nothing to it. In a C > compiler I can get this to return the version number of the library so I > know it's working. > > In Labview (7.0) the closest I can get to this prototype using the "Call > Library" node is > > unsigned char gpgme_check_version(CStr req_version); > CStr gpgme_check_version(CStr req_version); > > I've also tried not specifying the argument passed to the function. If it > is specified, I wire an empty string to the input. > > When the VI runs, no data comes back. There are no errors- the VI is > executable and Labview doesn't segfault. I know that when getting arrays > back from a function in general you have to supply preallocated space, but > there's no input terminal as such for the return code- just a shaded > placeholder. Nonetheless, I can wire a generously-sized string to it with no > errors, although it doesn't help. Dear Dr. Craig, I've never used the return type as string (I don't remember if this type exsits in version before LV7), I always leave it as argument, because I know this way it always work. If as argument, you need to preallocate a space for the string. Regards, Irene He www.geocities.com/irene_he www.hytekautomation.com
