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How do I convert a char into unsigned char?

Posted on 2010-09-20
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Last Modified: 2012-05-10
Hi Experts,
I have an array of unsigned char
static unsigned char m_ucTxBuffer[255];
I use memcpy to initialize the first element:
memcpy(&m_ucTxBuffer[0],"\55");
But In another part of the program I want to intialize the second element.  I use Borland C++ and I have an edit box that the user types in the value that will go into the second element.  The way Borland handles EditBoxes is
char normalBuf [10];
strcpy(normalBuf,Edit->Text.c_str())
when I try to copy normalBuf to m_ucTxBuffer[1] it complains that it can't convert char to unsigned char.
How would I put the value in normalBuf into m_ucTxBuffer?
Thanks
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Question by:farcuri
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Mohamed Abowarda earned 500 total points
ID: 33720204
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by:Infinity08
ID: 33720631
Depends what you want the unsigned char buffer to contain.

But if I understand what you want correctly, just do the cast (ie. ignore the compiler warning) :

        char c;
        unsigned char uc = (unsigned char) c;
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Expert Comment

by:Superdave
ID: 33721059
I'm not sure what you're doing makes sense.  memcpy should have three arguments; the third should be 1 if you want to copy one char but you could just as well say
m_ucTxBuffer[0]='\55'; for the first example.
Then, how are you copying the text buffer?  If you want to copy it to positions 1-10 do
memcpy(&m_ucTxBuffer[1],normalBuf,10);

Signed vs. unsigned shouldn't matter much; memcpy should be declared to use void * anyway so I'm surprised if it gives a warning.  If you use strcpy instead, you could just say (char *)&m_ucTxBuffer[1], or (char *)(m_ucTxBuffer+1) which is the same thing.
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Expert Comment

by:greatsubash
ID: 33722821
Hi,
Please refer the following link,
http://www.cplusplus.com/forum/unices/10272/

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