ReadByte ( stream )
Parameters
| stream - a file stream opened for reading, or a TCP stream |
Description
|
Reads one byte from a file or stream and returns it as a value from 0 to 255. A byte is the smallest unit you can read - 8 bits, holding 0 to 255. The result is always unsigned: a -1 stored with WriteByte comes back as 255, because only the low 8 bits of the original number were kept. Since text characters are single bytes, ReadByte can also walk through a file character by character (Chr$ turns the value back into a character). Reading past the end of the file is not an error - you just get 0 - so use Eof to know when to stop. On a TCP stream the call waits until a byte arrives; check ReadAvail first if you cannot afford to wait. See also: WriteByte, ReadShort, ReadInt, Eof, ReadAvail. |
Example
; ReadByte Example ; ---------------- ; Save a few bytes so there is something to read file=WriteFile("demo_bytes.dat") WriteByte file,65 WriteByte file,100 WriteByte file,255 CloseFile file ; ReadByte reads a single byte and always returns 0 to 255 file=ReadFile("demo_bytes.dat") a=ReadByte(file) b=ReadByte(file) c=ReadByte(file) CloseFile file Print "Bytes read from demo_bytes.dat:" Print " "+a+" (the ASCII code for "+Chr$(a)+")" Print " "+b Print " "+c+" (the largest value a byte can hold)" ; Clean up the demo file DeleteFile "demo_bytes.dat" Print "Deleted demo_bytes.dat" Print "" Print "Press any key to close the example" WaitKey End
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