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I adopt select()...sysread()...syswrite() mechanism to handle socket messages, where messages are sysread() into $buffer (binary) before they are syswritten.
Now I want to change two bytes of the message, which denote the length of the whole message. At first, I use following code:
my $msglen=substr($buffer,0,2); # Get the first two bytesmy $declen=hex($msglen);$declen += 3;substr($buffer,0,2,$declen); # change the length
However, it doesn't work in this way. If the final value of $declen is 85, then the modified $buffer will be "0x35 0x35 0x00 0x02...". I insert digital number to $buffer but finally got ASCII!
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