Re^3: How to use 'unsigned char' C data type with Win32::API (&255)

I didn't look in detail (I suspect the relevant details could be buried quite deep), but it looks likely to be a bug in Win32::API to me.

Even if not a bug in Win32::API, it looks like an uninitialized four-byte value is having only some of its bytes overwritten. So why not just work around it and pull out only the byte you care about?

$ret &= 0xFF;
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Though, the return values you show actually show the lowest two bytes being consistently 0x7298, which seems rather unlikely.

printf "%d 0x%x\n", $_, $_
    for 53113496, 52195992, 52851352, 52458136, 51540632
53113496 0x32a7298
52195992 0x31c7298
52851352 0x3267298
52458136 0x3207298
51540632 0x3127298
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...So it could easily be neither of the things I guessed. Is 0x98 (152) the value you are expecting to get?

- tye

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Re^4: How to use 'unsigned char' C data type with Win32::API (&255) by sam_bakki (Pilgrim) on Mar 13, 2012 at 09:41 UTC
Hi tye I suppose to get like below C code's API call. `# C Code # printf ("\n \n DEV: %d , %c , %x ", i2cGetDeviceAddress(),i2cGetDevi +ceAddress(),i2cGetDeviceAddress()); # # Output: DEV: 70 , F , 46` [download] I used following code get rid of un initialized bytes `$ret = unpack ('C',pack ('i*',$ret)); #This gives 152 but this is not +i want :(` [download]	[reply] [d/l] [select]
Re^4: How to use 'unsigned char' C data type with Win32::API (&255) by sam_bakki (Pilgrim) on Mar 13, 2012 at 10:46 UTC
Hi tye I suppose to get like below C code's API call. `# C Code # printf ("\n \n DEV: %d , %c , %x ", i2cGetDeviceAddress(),i2cGetDevi +ceAddress(),i2cGetDeviceAddress()); # # Output: DEV: 70 , F , 46` [download] I used following code get rid of un initialized bytes `$ret = unpack ('C',pack ('i*',$ret)); #This gives 152 but this is not +i want :(` [download]	[reply] [d/l] [select]