Обсуждение: libpq.a and Xcode on Mac OS X
Hi Folks:
In an attempt to optimize retrieving BLOBs from my PostgreSQL DB I embarked on a mission to write functions in C to directly access the back-end using the libpq.a library.
I copied libpq.a from my /usr/local/pgsql/lib/libpq.a installation into my Xcode project, added all necessary includes and the standard libpq-fe.h header. My test program builds and runs fine, links against libpq.a no problem, but upon execution of a simple:
conn = PQconnectdb(conninfo);
(taken from the Postgres examples) the debugger stops in asm code (presumably the library) with the error:
0x90047960 <+0000> li r0,37
0x90047964 <+0004> sc
0x90047968 <+0008> b 0x90047970 <kill+16>
0x9004796c <+0012> blr
...
Cannot access memory at address 0x0.
I'm using Xcode 2.4 on Mac OS X 10.4.8.
Do you have any ideas or does someone have a simple Xcode project that would show me how to properly use libpq.a directly from a C program? Is there an OS X-specific site with examples I could browse through?
Any advice greatly appreciated. I'm stuck very early in my attempts!
thanks,
Peter.
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Peter K. Stys, MD
Professor of Medicine(Neurology), Senior Scientist
Ottawa Health Research Institute, Div. of Neuroscience
Ottawa Hospital / University of Ottawa
Ontario, CANADA
tel: (613)761-5444
fax: (613)761-5330
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"Peter K. Stys" <pstys@ohri.ca> writes:
> ... My test program builds and runs fine, links
> against libpq.a no problem, but upon execution of a simple:
> conn = PQconnectdb(conninfo);
> (taken from the Postgres examples) the debugger stops in asm code
> (presumably the library) with the error:
> Cannot access memory at address 0x0.
What conninfo string are you passing?
regards, tom lane
On Feb 28, 2007, at 4:47 PM, Peter K. Stys wrote: > Do you have any ideas or does someone have a simple Xcode project > that would show me how to properly use libpq.a directly from a C > program? Is there an OS X-specific site with examples I could > browse through? These sites might have some useful code and examples: http://www.karppinen.fi/baseten/ http://sourceforge.net/projects/pgsqlformac/ John DeSoi, Ph.D. http://pgedit.com/ Power Tools for PostgreSQL