What are these Commands??

Question

I wanted to know what these commands are? and what are they used for?.
I have just started to learn PowerShell, so if you explain this to me in a simple language, it would be most appreciated.
  forfiles
  runas
  attrib
  icacls
Thank You.

Answer 1

You can get summary documantation by running these commands
forfiles.exe /? | more
attrib.exe /? | more
icacls.exe /? | more
But runas for some reason does not produce pipeline output when you run it that way
This command does produce help text for runas, but it is not redirectable.
I don't know why.
runas.exe
These are all executables of various windows vintages. They each output their "/?" help text using whatever I/O method their authors thought was appropriate. The fact that runas's output is not redirectable is because that is how it was coded - and it is
not clear if this was done on purpose. You can test this from a cmd.exe shell.
The point is that such executables are outside the control of Powershell. The fact that their help text coding is inconsistent is more the fault of cmd.exe for not having included a consistent help mechanism. But here's an even worse example - try this:
    notepad /?
this ugliness is because it is mostly the cmd.exe console based executables that honour the "/?" parameter. But they are not all bad - try this one:
    mstsc /?
The long and the short of it is this: if is not a native powershell command, good luck with getting help on it, and good luck getting it to work as you want it to from a powershell script.
I was going to say that you can use powershell's get-help cmdlet to determine if a command is native to powershell, but this is somewhat confused by the about_*.txt files, i.e.:
PS C:\Users\Al> get-help attrib.exe
Get-Help : Cannot find Help for topic "attrib.exe".
At line:1 char:10
+ get-help <<<< attrib.exe
+ CategoryInfo : ResourceUnavailable: (:) [Get-Help], HelpNotFoundException
+ FullyQualifiedErrorId : HelpNotFound,Microsoft.PowerShell.Commands.GetHelpCommand
PS C:\Users\Al> get-help attrib
TOPIC
about_Functions_CmdletBindingAttribute
SHORT DESCRIPTION
Describes an attribute that declares a function that acts similar to a
compiled cmdlet.
LONG DESCRIPTION
When you write functions, you can add the CmdletBinding attribute so that
Windows PowerShell will bind the parameters of the function in the same
way that it binds the parameters of compiled cmdlets. When this attribute
is declared, Windows PowerShell also sets the $PSCmdlet automatic variable.
When you use cmdlet binding, unknown parameters and positional arguments
that have no matching positional parameters cause parameter binding to
fail. Also, a function or script with cmdlet binding does not use the
$args variable.
Note: Compiled cmdlets use the required Cmdlet attribute, which is similar
to the CmdletBinding attribute that is described in this topic.
The following example shows the outline of a function that specifies all
the optional arguments of the CmdletBinding attribute. A brief description
of each argument follows this example.
[CmdletBinding(SupportsShouldProcess=<Boolean>,
ConfirmImpact=<String>,
DefaultParameterSetName=<String>)]
Param ($Parameter1)
Begin{}
Process{}
End{}
SupportsShouldProcess
When the SupportsShouldProcess argument is set to true, it indicates that
the function supports calls to the ShouldProcess method, which is used to
prompt the user for feedback before the function makes a change to the
system. When this argument is specified, the Confirm and WhatIf
parameters are enabled for the function.
For more information about confirmation requests, see "Requesting
Confirmation" in the MSDN (Microsoft Developer Network) library at
http://go.microsoft.com/fwlink/?LinkId=136658.
DefaultParameterSetName
The DefaultParameterSetName argument specifies the name of the parameter
set that Windows PowerShell will attempt to use when it cannot determine
which parameter set to use. You can avoid this issue by making the
unique parameter of each parameter set a mandatory parameter.
ConfirmImpact
The ConfirmImpact argument specifies when the action of the function
should be confirmed by a call to the ShouldProcess method. The call to
the ShouldProcess method displays a confirmation prompt only when the
ConfirmImpact argument is equal to or greater than the value of the
$ConfirmPreference preference variable. (The default value of the
argument is Medium.) Specify this argument only when the
SupportsShouldProcess argument is also specified.
SEE ALSO
about_Functions_Advanced
about_Functions_CmdletBindingAttribute
about_Functions_ParameterAttributes
PS C:\Users\Al>
appending .exe doesn't help, and leaving it off for attrib causes get-help to assume that you had typed
    get-help about_Functions_CmdletBindingAttribute
Al Dunbar -- remember to 'mark or propose as answer' or 'vote as helpful' as appropriate.