UEFI Programming Model

The UEFI Shell provides a programming API. You can use it to write your own UEFI applications for calling some of the Shell programmatic APIs or protocols. For more information, see the UEFI Shell Specification and EDK2. The UEFI Shell provides a programming API as listed in the following table. EFI_SHELL_PROTOCOL provides Shell services to UEFI applications. It provides UEFI Shell applications access to the low-level Shell functions, including files, pipes, environment variables, the current working directory, mappings, help text, aliases, and launching Shell applications and scripts.

Table 13: UEFI Application APIs
Function Type	Function Name	Description
`EFI_SHELL_EXECUTE`	Execute	Causes the Shell to parse and execute the command line.
`EFI_SHELL_GET_ENV`	GetEnv	Gets the environment variable.
`EFI_SHELL_SET_ENV`	SetEnv	Changes a specific environment variable.
`EFI_SHELL_GET_ALIAS`	GetAlias	Retrieves the alias for a specific Shell command.
`EFI_SHELL_SET_ALIAS`	SetAlias	Adds or removes the alias for a specific Shell command.
`EFI_SHELL_GET_HELP_TEXT`	GetHelpText	Returns help information about a specific command.
`EFI_SHELL_GET_DEVICE_PATH_FROM_MAP`	GetDevicePathFromMap	Returns the device path that corresponds to a mapping.
`EFI_SHELL_GET_MAP_FROM_DEVICE_PATH`	GetMapFromDevicePath	Returns the mapping that corresponds to a particular device path.
`EFI_SHELL_GET_DEVICE_PATH_FROM_FILE_PATH`	GetDevicePathFromFilePath	Converts a file path to a device path, where all mappings have been replaced with the corresponding device paths.
`EFI_SHELL_GET_FILE_PATH_FROM_DEVICE_PATH`	GetFilePathFromDevicePath	Converts a device path to a file path, where the portion of the device path corresponding to one of the mappings is replaced with that mapping.
`EFI_SHELL_SET_MAP`	SetMap	Creates, updates, or deletes a mapping between a device and a device path.
`EFI_SHELL_GET_CUR_DIR`	GetCurDir	Returns the current directory on a device.
`EFI_SHELL_SET_CUR_DIR`	SetCurDir	Changes the current directory on a device.
`EFI_SHELL_OPEN_FILE_LIST`	OpenFileList	Opens the files that match the path pattern specified.
`EFI_SHELL_FREE_FILE_LIST`	FreeFileList	Frees the file list created by OpenFileList().
`EFI_SHELL_REMOVE_DUP_IN_FILE_LIST`	RemoveDupInFileList	Deletes the duplicate files in the given file list.
`EFI_SHELL_BATCH_IS_ACTIVE`	BatchIsActive	Displays whether any script files are being processed.
`EFI_SHELL_IS_ROOT_SHELL`	IsRootShell	Verifies whether the active Shell is the root Shell.
`EFI_SHELL_ENABLE_PAGE_BREAK`	EnablePageBreak	Enables the page break output mode.
`EFI_SHELL_DISABLE_PAGE_BREAK`	DisablePageBreak	Disables the page break output mode.
`EFI_SHELL_GET_PAGE_BREAK`	GetPageBreak	Gets the enable status of the page break output mode.
`EFI_SHELL_GET_DEVICE_NAME`	GetDeviceName	Gets the name of the device specified by the device handle.
`EFI_SHELL_GET_FILE_INFO`	GetFileInfo	Displays information about a specific file handle.
`EFI_SHELL_SET_FILE_INFO`	SetFileInfo	Changes information about a specific file handle.
`EFI_SHELL_OPEN_FILE_BY_NAME`	OpenFileByName	Opens a file specified by name and returns a file handle.
`EFI_SHELL_CLOSE_FILE`	CloseFile	Closes an open file.
`EFI_SHELL_CREATE_FILE`	CreateFile	Creates a file.
`EFI_SHELL_READ_FILE`	ReadFile	Reads data from a file.
`EFI_SHELL_WRITE_FILE`	WriteFile	Writes data to a file.
`EFI_SHELL_DELETE_FILE`	DeleteFile	Deletes a file.
`EFI_SHELL_DELETE_FILE_BY_NAME`	DeleteFileByName	Deletes a file by name.
`EFI_SHELL_GET_FILE_POSITION`	GetFilePosition	Displays the current read/write position within a file.
`EFI_SHELL_SET_FILE_POSITION`	SetFilePosition	Changes the current read/write position within a file.
`EFI_SHELL_FLUSH_FILE`	FlushFile	Writes all buffered data to a file.
`EFI_SHELL_FIND_FILES`	FindFiles	Displays all files that match a pattern in a file list.
`EFI_SHELL_FIND_FILES_IN_DIR`	FindFilesInDir	Displays all files in a specified directory in a file list.
`EFI_SHELL_GET_FILE_SIZE`	GetFileSize	Displays the size of a file.
`EFI_SHELL_OPEN_ROOT`	OpenRoot	Displays the root directory of a file system.
`EFI_SHELL_OPEN_ROOT_BY_HANDLE`	OpenRootByHandle	Displays the root directory of a file system on a particular handle.
`EFI_EVENT`	ExecutionBreak	An event signaled by the UEFI Shell when the user presses CTRL-C to indicate that the current UEFI Shell command execution should be interrupted.
`UINT32`	MajorVersion	The major version of the Shell environment.
`UINT32`	MinorVersion	The minor version of the Shell environment.