Class StandardHandleInfo

This static class provides type-safe managed methods to determine the true redirection state of a standard console handle, including, if applicable, learning the name of the file to which it is redirected.

Inheritance

System.Object

StandardHandleInfo

Namespace: WizardWrx.ConsoleStreams

Assembly: WizardWrx.ConsoleStreams.dll

Syntax

public static class StandardHandleInfo : object

Remarks

The standard properties on the Process (all versions) and Console (version 4.5 and newer) objects report based solely on redirections brought about by the Base Class Library. They completely ignore redirection that happens in the shell, before the process started. Hence, to learn the true redirection state requires a couple of Platform Invoke calls into the Windows API, which this class provides through type-safe wrappers.

Fields

| Improve this Doc View Source

INVALID_HANDLE_VALUE

When a routine, such as GetStandardHandle cannot return a usable file handle, this is the return value, cast to IntPtr, as is the expected file handle.

Declaration

public static readonly IntPtr INVALID_HANDLE_VALUE

Field Value

Type	Description
IntPtr

Remarks

Were it not that IntPtr is a structure, INVALID_HANDLE_VALUE would be defined as a public constant.

| Improve this Doc View Source

INVALID_MODULE_HANDLE

When a routine, such as GetModuleHandle cannot return a usable module handle, this is the return value, cast to IntPtr, as is the expected module handle.

Declaration

public static readonly IntPtr INVALID_MODULE_HANDLE

Field Value

Type	Description
IntPtr

Remarks

Were it not that IntPtr is a structure, INVALID_HANDLE_VALUE would be defined as a public constant.

Methods

| Improve this Doc View Source

GetRedirectedFileName(StandardHandleInfo.StandardConsoleHandle)

Get the name of the file to which a specified standard handle is redirected.

Declaration

public static string GetRedirectedFileName(StandardHandleInfo.StandardConsoleHandle penmStdHandleID)

Parameters

Type	Name	Description
StandardHandleInfo.StandardConsoleHandle	penmStdHandleID	Use a member of the StandardConsoleHandle enumeration to designate the desired standard console stream.

Returns

Type	Description
System.String	If the file is redirected, the returned string contains the fully qualified name of the file to which it is redirected. If the handle is attached to its console (that is, not redirected), the return value is the empty string.

| Improve this Doc View Source

GetStandardHandleState(StandardHandleInfo.StandardConsoleHandle)

Get the redirection state of a specified standard console stream.

Declaration

public static StandardHandleInfo.StandardHandleState GetStandardHandleState(StandardHandleInfo.StandardConsoleHandle penmStdHandleID)

Parameters

Type	Name	Description
StandardHandleInfo.StandardConsoleHandle	penmStdHandleID	Use a member of the StandardConsoleHandle enumeration to designate the desired standard console stream.

Returns

Type	Description
StandardHandleInfo.StandardHandleState	The return value is one of the following. StandardHandleState.Attached means that the specified stream is attached to its console. StandardHandleState.Redirected means that the specified stream is redirected. Call GetRedirectedFileName to get the fully qualified name of the file to which it is redirected.

Remarks

In all versions of the framework, the following properties report inaccurately on the true state of the console stream.

System.Diagnostics.Process.StartInfo.RedirectStandardInput ,
System.Diagnostics.Process.StartInfo.RedirectStandardOutput ,
System.Diagnostics.Process.StartInfo.RedirectStandardError ,

The following properties, added in version 4.5, also report incorrectly.

Console.IsErrorRedirected
Console.IsInputRedirected
Console.IsOutputRedirected

The above properties report inaccurately because their report is based entirely on changes made by calls to methods on the Console class. They exhibit no knowledge, whatsoever, of what the underlying operating system does in response to shell commands to redirect one or more of the standard console streams.

On the other hand, since StandardHandleState gets its information from GetConsoleMode, a native Windows API routine, its report takes into account console stream redirections that are the result of shell commands.

| Improve this Doc View Source

GetWin32StatusCode()

Get the last Win32 status code logged by Marshal.GetLastWin32Error.

Declaration

public static Int32 GetWin32StatusCode()

Returns

Type	Description
Int32	The return value is the value returned by the last call to Marshal.GetLastWin32Error.

Remarks

As is true of the other methods defined by this class, this method is not yet thread-safe.