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Read.md

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NAME

Read -- Read bytes of data from a file

SYNOPSIS

    actualLength = Read( file, buffer, length )
    D0                   D1    D2      D3

    LONG Read(BPTR, void *, LONG)

FUNCTION

Data can be copied using a combination of Read() and Write. Read() reads bytes of information from an opened file (represented here by the argument 'file') into the buffer given. The argument 'length' is the length of the buffer given.

The value returned is the length of the information actually read. So, when 'actualLength' is greater than zero, the value of 'actualLength' is the the number of characters read. Usually Read will try to fill up your buffer before returning. A value of zero means that end-of-file has been reached. Errors are indicated by a value of -1.

Note: this is an unbuffered routine (the request is passed directly to the filesystem.) Buffered I/O is more efficient for small reads and writes; see FGetC.

INPUTS

file - BCPL pointer to a file handle buffer - pointer to buffer length - integer

RESULTS

actualLength - integer

SEE ALSO

Open, Close, Write, Seek, FGetC