# uio.h ## **Overview** **Related Modules:** [IO](IO.md) **Description:** Provides functions and structures related to input/output \(I/O\) to a file or buffer. You can use the functions provided in this file to read files to the buffer or read information from the buffer to files. **Since:** 1.0 **Version:** 1.0 ## **Summary** ## Functions

Function Name	Description
readv (int fd, const struct iovec *iov, int iovcnt)	ssize_t Reads the data of fd to iov.
writev (int fd, const struct iovec *iov, int iovcnt)	ssize_t Writes a given length of data into a file.
preadv (int fd, const struct iovec *iov, int iovcnt, off_t offset)	ssize_t Reads the data in a file whose fd offset is offset to the multi-group buffer space pointed to by iov.
pwritev (int fd, const struct iovec *iov, int iovcnt, off_t offset)	ssize_t Writes the data of a multi-group buffer space pointed to by iov to the offset of fd.