Compiling a program the embeds python

[Robin Munn]

Ben Lamb <news03 at zurgy.org> wrote:
> 
> I'm trying to compile an example program written in C that embeds Python.
> The porgram is:
> 
[snip]
> 
> I use the following to compile it:
> 
> ben at localhost:~/prog/pyembed$ gcc -I/usr/local/include/python2.2
> -L/usr/local/lib/python2.2/config -Xlinker -export-dynamic -lm -lpython2.2
> -ldl -lpthread -lutil pyembed.c
> 
[snip]
> 
> Please can someone point out what I am doing wrong.

The -l options, which specify which libraries to link against, need to
come *after* the file(s) that need those libraries. Yes, this breaks the
Unix rule-of-thumb that options always come first, and parameters
second. Your command line should be:

    ben at localhost:~/prog/pyembed$ gcc -I/usr/local/include/python2.2
    -L/usr/local/lib/python2.2/config -Xlinker -export-dynamic pyembed.c
    -lm -lpython2.2 -ldl -lpthread -lutil

Check the gcc manpage, and read the section that describes the -l
command. On my system, it starts at line 3630 of the manpage. You'll
find the following paragraph:

    It makes a difference where in the command you write this option;
    the linker searches and processes libraries and object files in the
    order they are specified.  Thus, foo.o -lz bar.o searches library z
    after file foo.o but before bar.o.  If bar.o refers to functions in
    z, those functions may not be loaded.

Hope this helps.

-- 
Robin Munn <rmunn at pobox.com>
http://www.rmunn.com/
PGP key ID: 0x6AFB6838    50FF 2478 CFFB 081A 8338  54F7 845D ACFD 6AFB 6838