First, thanks for the display in hex, that will help me a lot in future C (if I'm ever here again after this project)
I've found the discussion of cast in the FM, it is several chapters down from where I was in a straight thru read of the Language reference. It looks like this will let me make progress. I said a language is a language and it's true, but I also know it takes a lot of practice to become fluent. I may not see C again for years once I get this thing working. I really appreciate the help the listserves can provide/ Dave Gibney Information Technology Services Washington State University > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Don Poitras > Sent: Friday, November 04, 2011 3:55 PM > To: [email protected] > Subject: Re: C newbie - pass a LDAP handle out to calling routine > > Dave, > You need to cast to a pointer type that memcpy (or whatever) can > handle. e.g. > > memcpy(foo, *((char *) ld), 10); > > If you want to use this a lot, it might be better to just copy > to a pointer of another type: > > char *bar; > > bar = (char *) ld; > memcpy(foo, *bar, 10); > > Also, I find it beneficial to display addresses in hex. e.g. > > printf("ld before bind :%08X\n",ld); > > In article <0DE6A9840123E547B061AC5B6765C0261C148A@EXMB- > 05.ad.wsu.edu> you wrote: > > This is my first experience with C, but a language is a language after the > 3rd or 4th :) > > I'm calling C for LDAP queries from Natural (Software AG "4"GL) in batch. > And it works, sort of. > > One FM is IBM Tivoli Directory Server Client Programming for z/OS > > > If I use the sequence ldap_init, ldap_simple_bind_s, ldap_search, > ldap_unbind, it gets overloaded after 5 calls at the speed of batch. If I > leave > out the unbind, it works for thousands of calls, but there is an obvious > memory leak. > > So, I want to anchor the ldap handle in the main driving program. I made a > simple C stub: > > > > extern int ret2nat (int *back_value, LDAP *ld, char *msg) > > #include <ldap.h> > > > In ldap.h there is: > > typedef struct ldap LDAP; > > > The examples use: > > LDAP * ld; > > To declare an ldap_handle which according to the listing is an: > > ld 6270-1:1931 Class = parameter, Length = 4 > > Type = pointer to incomplete struct ldap > > > > I have a function: > > LDAP * bind_adlds(char *hostname, char *container, char *msg) > > And I call it: > > printf("ld before bind :%d\n",ld); /* ld before bind > > :286352012 > > ld = bind_adlds(hostname, container, msg) ; > > printf("ld after bind :%d\n",ld); /* ld after bind > > :283317144 > > > but the value is not returned to the caller of ret2nat. > > > > Any attempts to use *ld in an assignment or even memcpy() get a complier > message: > > ERROR CCN3285 /u/ldap/test.c:46 The indirection operator cannot be > applied to a pointer to an incomplete struct or union. > > Or > > WARNING CCN3068 /u/ldap/test.c:46 Operation between types "int*" > and "pointer to an incomplete type" is not allowed. > > > As I said, I am just learning how to spell C. I know I am fighting some > > kind of > battle of types. I welcome even derisive comments, if in the end thay help. > > > Dave Gibney > > Information Technology Services > > Washington State University > > -- > Don Poitras - SAS Development - SAS Institute Inc. - SAS Campus Drive > [email protected] (919) 531-5637 Cary, NC 27513 > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
