Xiao/Rob,
My feeling is that the problem lies here:
> try_pl_f4a3.xs: In function 'get_proc_name':
> try_pl_f4a3.xs:35:1: warning: function returns address of local variable
Basically the get_proc_name function returns a pointer that is local
to the function stack (and therefore is possibly damaged after the
function call).
Try declaring szProcessName as static (or making it global) to see if
that fixes your problem.
Patrick
On Tue, Sep 6, 2011 at 11:47 PM, Sisyphus <sisyph...@optusnet.com.au> wrote:
>
> ----- Original Message ----- From: "Xiao Yafeng" <xyf.x...@gmail.com>
> To: "inline" <inline@perl.org>
> Cc: "Sisyphus" <sisyph...@optusnet.com.au>
> Sent: Wednesday, September 07, 2011 2:28 AM
> Subject: strange line
>
>
>> I wrote a simple snippet to list processes name and pid on windows. but
>> the
>> output returns a strange line. below is the code:
>>>
>>>
>>>
>>> use strict;
>>
>> use warnings;
>>
>> use Inline C => DATA =>
>> LIBS => '-luser32 -lkernel32 -lpsapi';
>>
>> my $a = process_list();
>> map { print; print get_proc_name($_);print "\n"; } @{$a};
>>
>>
>> __END__
>> __C__
>>
>> #include <windows.h>
>> #include <stdio.h>
>> #include <tchar.h>
>> #include <psapi.h>
>>
>> char* get_proc_name( int processID )
>> {
>> TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>");
>>
>>
>> HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
>> PROCESS_VM_READ,
>> FALSE, processID );
>>
>>
>> if (NULL != hProcess )
>> {
>> HMODULE hMod;
>> DWORD cbNeeded;
>>
>> if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
>> &cbNeeded) )
>> {
>> GetModuleBaseName( hProcess, hMod, szProcessName,
>> sizeof(szProcessName)/sizeof(TCHAR) );
>> }
>> }
>>
>> CloseHandle( hProcess );
>> return szProcessName;
>> }
>>
>>
>>
>>
>>
>> SV* process_list(){
>>
>> DWORD aProcesses[1024], cbNeeded, cProcesses;
>> unsigned int i;
>> EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded );
>>
>> cProcesses = cbNeeded / sizeof(DWORD);
>> AV* AV_procs = newAV();
>> for ( i = 0; i < cProcesses; i++ )
>> {
>> if( aProcesses[i] != 0 )
>> {
>> av_push(AV_procs, newSViv( aProcesses[i] ) );
>> }
>> }
>> return newRV_inc(AV_procs);
>> }
>>
>>
>>
>> __OUTPUT__
>>
>> C:\>perl test.pl
>> 4P ?F > <== strange line
>> 292<unknown>
>> 372<unknown>
>> 432<unknown>
>
> Haven't yet had a chance to take a thorough look at this.
> I inserted the following near the beginning of your script:
>
> use Inline C => Config =>
> BUILD_NOISY => 1;
>
> That way you get to see any compiler warnings that are emitted during the C
> compilation, and with my cc-4.5.2 build of perl-5.14 I saw:
>
> try_pl_f4a3.xs: In function 'get_proc_name':
> try_pl_f4a3.xs:35:1: warning: function returns address of local variable
> try_pl_f4a3.xs: In function 'process_list':
> try_pl_f4a3.xs:57:5: warning: passing argument 2 of 'Perl_newRV' from
> incompatible pointer type
> C:\MinGW\perl\lib\CORE/proto.h:2567:19: note: expected 'struct SV * const'
> but argument is of type 'struct AV *'
>
> Whether there's anything relevant there, I don't know.
>
> I get different output to you, of course. But in the middle of the output I
> also got one odd-looking line:
>
> 1348┤aæ☻↑:ñ $ ↑:ñ ~↑☻
>
> When I switched to a gcc-3.4.5 build of perl-5.12, I found out what 1348
> really was:
> 1348TomTomHOMERunner.exe
>
> But then I got a strange line at the beginning of the output:
>
> 4ð¬─w4§Å ↑
> whereas, with gcc-4.5.2, that had been:
> 4<unknown>
>
> This is probably a good question for somewhere like perlmonks, where there's
> people with a good understanding of windows itself.
>
> Cheers,
> Rob
>
--
=====================
Patrick LeBoutillier
Rosemère, Québec, Canada
