Обсуждение: RE: [INTERFACES] PgConnection

Thanks for your response.

I tried your suggestion, and thing seem to go a little bit better--I still
receive one error at compile time, though.  (quite frustrating :) )

Hee's the error I receive:
$> g++ -I/usr/local/pgsql/include mytest.cpp -L/usr/local/pgsql/lib -lpq++
-lpq
/usr/local/pgsql/lib/libpq.a(fe-auth.o): In function 'pg_password_sendauth':
fe-auth.o(.text+0.17): undefined reference to 'crypt'

I even tried making sure that crypt.h was in g++'s search path, but I still
got the same error....

Any ideas?

TIA
-Jason




-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Thursday, October 22, 1998 9:58 AM
To: Vasquez, Jason
Cc: pgsql-interfaces@hub.org
Subject: Re: [INTERFACES] PgConnection


"Vasquez, Jason" <Jason.Vasquez@Connect.Xerox.com> writes:
> I've read the documentation about using the C++ interface to Postgres, but
I
> seem to be havin trouble getting anything to compile.  Following the
example
> included with the distribution, I have done something similar to this:
> #include <iostream.h>
> #include <libpq++.h>
> void main() {
>   PgDatabase data ("foo");
> yadayadayada
> }
> Whenever I do this, I get a compile error stating that there is an
undefined
> reference to PgConnection.

Compile error, or link error?  I tried the same, and got complaints
about the linker not being able to find several PgConnection routines
until I added "-L/usr/local/pgsql/lib -lpq++ -lpq" to the command line:

$ g++ -I/usr/local/pgsql/include pgtest.cc
collect2: ld returned 1 exit status
/bin/ld: Unsatisfied symbols:
   PgConnection::PgConnection(void)(code)
   PgConnection::PgConnection(char const *)(code)
   PgConnection::~PgConnection(void)(code)
   PQfnumber (code)

$ g++ -I/usr/local/pgsql/include pgtest.cc -L/usr/local/pgsql/lib -lpq++
-lpq
[ no complaint ]

If you're using shared libraries there are also possibilities for
installation problems that prevent libpq++ from finding libpq at run
time, but evidently you're not getting that far yet :-(.

            regards, tom lane

"Vasquez, Jason" <Jason.Vasquez@Connect.Xerox.com> writes:
> Hee's the error I receive:
> $> g++ -I/usr/local/pgsql/include mytest.cpp -L/usr/local/pgsql/lib -lpq++ -lpq
> /usr/local/pgsql/lib/libpq.a(fe-auth.o): In function 'pg_password_sendauth':
> fe-auth.o(.text+0.17): undefined reference to 'crypt'

> I even tried making sure that crypt.h was in g++'s search path, but I still
> got the same error....

This is the same problem as before: you are seeing a link-time error not
a compile-time error.  You have to pay attention to whether the library
file can be found as well as whether the header file can be found.

On some machines the crypt functions are not in the standard C library
but in a separate file that you have to write "-lcrypt" to link in.
Perhaps yours is like that.

            regards, tom lane