Get metadata of a file descriptor.
fd_fdstat_get() function is used to retrieve the metadata of a file descriptor. It provides information about the state of the file descriptor, such as its rights, flags, and file type.
In POSIX systems, file descriptors are small, non-negative integers used to represent open files, sockets, or other I/O resources. They serve as handles that allow processes to read from or write to these resources. The
fd_fdstat_get() function allows applications to retrieve information about a specific file descriptor, gaining insights into its properties and characteristics.
;;; Note: This returns similar flags to `fcntl(fd, F_GETFL)` in POSIX, as well as additional fields. ;;; Get the attributes of a file descriptor. (@interface func (export "fd_fdstat_get") (param $fd $fd) ;;; The buffer where the file descriptor's attributes are stored. (result $error (expected $fdstat (error $errno))) )
ctx: A mutable reference to the function environment.
fd: The file descriptor whose metadata will be accessed.
buf_ptr: A WebAssembly pointer to a memory location where the metadata will be written.
The function returns an
Errno value indicating the success or failure of the operation.
In POSIX-compliant systems, file descriptors are fundamental to I/O operations. They are obtained through various system calls such as
pipe(). Each file descriptor maintains its own set of properties, including access rights, flags, and file type.
fd_fdstat_get() function corresponds to the POSIX
fstat() system call, which retrieves information about an open file descriptor. By invoking
fd_fdstat_get(), applications can query the metadata associated with a file descriptor and access relevant details, such as the file's mode, size, or ownership.
fd_fdstat_get() function retrieves the metadata of the specified file descriptor. It writes the metadata to the provided memory location. This allows applications to examine the properties of a file descriptor and make informed decisions based on its characteristics.