Hi all, I am writing an XS module, and calling Perl subs from C. I come to a point where I need to check for existence of a Perl sub ( given its name ), I get into trouble with get_cv ( perldoc perlapi ), which does not seem to handle each and every case. Here are the .xs and the test.pl file I use:
CCC.xs : 
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"


void inspect( char* name ) {
  if( get_cv( name, (I32)0 ) != NULL ) {
    printf( " &%s is defined\n", name );
    { 
      dSP ;
      PUSHMARK(SP) ;  
      call_pv( name, G_DISCARD | G_NOARGS );
    }
  }
}


MODULE = CCC        PACKAGE = CCC        


void
inspect( name )
  INPUT:
    char* name;

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test.pl : 

sub mysub {
  print "Hello from mysub !\n";
}

&CCC::inspect( "main::mysub" );

undef &mysub;

&CCC::inspect( "main::mysub" );

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When I run `make test', I get the following output : 

1..1
ok 1
 &main::mysub is defined
Hello from mysub !
 &main::mysub is defined
Undefined subroutine &main::mysub called at test.pl line 27.
make: *** [test_dynamic] Erreur 255

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So the first time it gets called, it works fine, but after undefining the sub, it does not detect the sub is undef and calls it. Note that the perlapi says that with get_cv you get NULL if "create" is not set and the subroutine does not exist. Is there a way to check for sub definedness rather then for sub existence ? Cheers, Philou

In reply to How to check for subroutine existence from within XS code by philou

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