[Overview][Constants][Types][Procedures and functions][Index] | Reference for unit 'BaseUnix' (#rtl)

# FpPRead

Positional read: read from file descriptor at a certain position.

## Declaration

Source position: bunxh.inc line 86

`function FpPRead(`
`fd: cint;`
`buf: pChar;`
`nbytes: TSize;`
`offset: TOff`
`):TsSize;`

## Description

FpPRead reads nbytes bytes from file descriptor fd into buffer buf starting at offset offset. Offset is measured from the start of the file. This function can only be used on files, not on pipes or sockets (i.e. any seekable file descriptor).

The function returns the number of bytes actually read, or -1 on error.

## Errors

On error, -1 is returned.

## See also

FpReadV |  | Vector read: Read into multiple buffers
FpPWrite |  | Positional write: write to file descriptor at a certain position.