fd_filestat_get()

Get the metadata of an open file.

Description

The fd_filestat_get() function is used to retrieve the metadata of an open file identified by a file descriptor. It provides information about the file's attributes, such as its size, timestamps, and permissions.

In POSIX systems, file descriptors are used to perform I/O operations on files. The fd_filestat_get() function allows applications to obtain the metadata of an open file, providing access to important details about the file.

Syntax

  ;;; Return the attributes of an open file.
  (@interface func (export "fd_filestat_get")
    (param $fd $fd)
    ;;; The buffer where the file's attributes are stored.
    (result $error (expected $filestat (error $errno)))
  )

Parameters

• ctx: A mutable reference to the function environment.
• fd: The file descriptor of the open file whose metadata will be read.
• buf: A WebAssembly pointer to a memory location where the metadata will be written.

Return Value

The function returns an Errno value indicating the success or failure of the operation.

Logging

This function has been instrumented with debug-level logging. It will log the following information:

• %fd: The file descriptor whose metadata is being retrieved.

Note

The fd_filestat_get() function retrieves the metadata of an open file identified by the provided file descriptor. The metadata includes information about the file's attributes, such as its size, timestamps, and permissions. The retrieved metadata is written to the specified memory location.