Description
The fd_read() function is used to read data from a file identified by the provided file descriptor (fd). It takes an array of iovec structures (iovec) describing the buffers where the data will be stored, the number of vectors (iovs_len) in the iovec array, and a pointer to store the number of bytes read. The function reads data from the file into the specified buffers and returns the number of bytes read.
In POSIX systems, reading data from a file typically involves updating the file cursor, which determines the next position from which data will be read. The fd_read() function allows reading data from a file without modifying the file cursor's position. This can be useful in scenarios where applications need to read data from a specific location in a file without altering the cursor's state.
Note
The fd_read() function allows reading data from a file identified by the file descriptor fd. It takes the file descriptor, an array of buffers where the data will be stored, the number of vectors in the iovec array, and a pointer to store the number of bytes read. The function reads data from the file into the specified buffers without modifying the file cursor's position. It returns an error code to indicate the success or failure of the operation. If the data is successfully read from the file, it returns Errno::Success. Otherwise, it returns an appropriate error code.