VMware offers more command-line interfaces for vSphere than PowerCLI. One of them is the vSphere Command-Line Interface (CLI). The vSphere CLI has a command named esxcli. PowerCLI has built-in support for this esxcli command in the Get-EsxCli cmdlet.

The syntax of the Get-EsxCli cmdlet is as follows:

Get-EsxCli -VMHost <VMHost[]> [-V2] [[-Server] <VIServer[]>] 
    [<CommonParameters>]

Use the Get-EsxCli cmdlet to connect to the esxcli functionality of a host and save the connection in a variable $esxcli:

PowerCLI C:> $esxcli = Get-EsxCli -VMHost 192.168.0.133

In the vSphere CLI, the command to get information about the CPUs in your host is:

C:>esxcli --server=192.168.0.133 hardware cpu list
Enter username: root
Enter password:

In PowerCLI, the command becomes a little different. The Get-EsxCLI cmdlet returns a PowerShell object, and you have to use the properties and methods of this object to create the commands. This is why you have to put dots between all of the words in the command. And if the last word is a method, you have to specify parentheses for a parameter list even if there are no parameters. The command from the preceding example becomes the following in PowerCLI:

PowerCLI C:> $esxcli.hardware.cpu.list()

You can, of course, use the vSphere documentation to find the available esxcli commands. But you can also use PowerCLI for help. If you type in a partial command, you will get a list of elements and methods that are possible for this command. Let's start with $esxcli itself:

PowerCLI C:> $esxcli


    =====================
EsxCli: 192.168.0.133


       Elements:
   ---------
   device
   elxnet
   esxcli
   fcoe
   graphics
   hardware
   iscsi
   network
   nvme
   rdma
   sched
   software
   storage
   system
   vm
   vsan

You can see that one of the elements is hardware. Let's try hardware as the next command:

PowerCLI C:> $esxcli.hardware


    =======================
EsxCliElement: hardware


       Elements:
   ---------
   bootdevice
   clock
   cpu
   ipmi
   memory
   pci
   platform
   smartcard
   trustedboot
   usb


       Methods:
   --------
   string Help()

You now have all of the command elements you can use after hardware. Let's try cpu:

PowerCLI C:> $esxcli.hardware.cpu


    ==================
EsxCliElement: cpu


       Elements:
   ---------
   cpuid
   global


       Methods:
   --------
   Cpu[] list()
   string Help()
   string Help(string methodName)

And now you have obtained the list() method that we used in the preceding example.

A lot of the esxcli commands also provide a help() method that gives information about the command. To get help about the $esxcli.hardware.cpu command, type the following command:

PowerCLI C:> $esxcli.hardware.cpu.help()


    ===================================================================
vim.EsxCLI.hardware.cpu
-------------------------------------------------------------------
CPU information.


    ChildElement
-------------------------------------------------------------------
- hardware.cpu.cpuid | Information from the CPUID instruction on ea
                     | ch CPU.
- hardware.cpu.globa | Information and configuration global to all
  l                  | CPUs.


    Method
-------------------------------------------------------------------
- list               | List all of the CPUs on this host.

If you want to know what the parameters for an esxcli method are, you can use the vSphere documentation, or you can use the Get-Member cmdlet:

PowerCLI C:> $esxcli.hardware.cpu | Get-Member


       TypeName:
VMware.VimAutomation.ViCore.Impl.V1.EsxCli.EsxCliElementImpl


    Name                    MemberType   Definition
----                    ----------   ----------
Help                    CodeMethod   string Help(); string Help(s...
list                    CodeMethod   vim.EsxCLI.hardware.cpu.list...
cpuid                   CodeProperty VMware.VimAutomation.Sdk.Uti...
global                  CodeProperty VMware.VimAutomation.Sdk.Uti...
ConvertToVersion        Method       T VersionedObjectInterop.Con...
Equals                  Method       bool Equals(System.Object obj)
GetHashCode             Method       int GetHashCode()
GetType                 Method       type GetType()
IsConvertableTo         Method       bool VersionedObjectInterop....
ToString                Method       string ToString()
ChildElements           Property     System.Collections.Generic.L...
Client                  Property     VMware.VimAutomation.ViCore....
FullName                Property     string FullName {get;}
Id                      Property     string Id {get;}
IsManagedObjectInstance Property     bool IsManagedObjectInstance...
Methods                 Property     System.Collections.Generic.L...
Name                    Property     string Name {get;}
Uid                     Property     string Uid {get;}