The fd_pread() function is used to read data from a file identified by the provided file descriptor (fd) at a specified offset (offset). Unlike regular reading operations, fd_pread() does not update the file cursor, making it a stateless operation. The function reads data into the provided buffers (iovs) and returns the number of bytes read.
In POSIX systems, file reading operations typically involve updating the file cursor, which determines the next position from which data will be read. However, fd_pread() allows reading data from a specific offset without modifying the file cursor's position. This can be useful in scenarios where applications need to read data from a file at a specific location without altering the cursor's state.
Note
The fd_pread() function allows reading data from a file at a specified offset without updating the file cursor. It provides a stateless alternative to the traditional Seek + Read operations. The function takes the file descriptor, an array of buffers to store the data, the offset indicating the starting position, and a pointer to store the number of bytes read.