The same old commands almost in VB.NET

Making ECC200 in VB.NET The same old commands almost

dash, name, space, value. After that, they never wonder if parameter names should start with a dash or a slash, or if there s supposed to be an equal sign or colon in between the name and value. It s dash, name, space, value, and never anything else. Parameter names are used consistently throughout the shell. If one cmdlet has a -computerName parameter, which is used for specifying a computer name, then most cmdlets that need a computer name will also have a -computerName parameter. Both parameter and cmdlet names are intended to be clear and meaningful. When you look at a cmdlet name like Get-Content, you should be pretty clear that it s getting some kind of content from something. A parameter name like -credential doesn t leave much to the imagination, either you should be pretty certain what that parameter is going to do. Because clear can sometimes mean lengthy, Microsoft gives you shortcuts for cmdlet names and parameter names, to save you some typing. Cmdlet names can be given shorter aliases, as we ve already discussed, and parameter names don t need to be typed in their entirety. For example, if -recurse is the only parameter of Get-ChildItem that starts with the letter r, then you only have to type -r and PowerShell will know what you mean. If a cmdlet has both a -computerName and -credential parameter, typing -comp will probably be enough for PowerShell to figure out that you mean the -computerName parameter.

This is another good place for me to remind you to be a neat, careful typist. GetChildItem-recurse is incorrect, because there s no space between the end of the cmdlet name and the dash that starts the parameter name. Get-ChildItem -recurse is correct, with that space in between the two elements. It s very, very important that you focus on those little typing details, because getting them wrong will generate sometimes-confusing errors that will do nothing but slow you down. PowerShell is all about consistency. That s not to say it s 100 percent consistent, because it is, after all, the product of many human beings, who do tend to make mistakes sometimes. But it s pretty consistent most of the time. In the previous chapter, I wrote about how graphical user interfaces (GUIs) offer features to help you figure out what you can do with them: right-click menus, tooltips, menus, and so forth. Programmers refer to those features as discoverability features, because they literally help you discover the tool s capabilities. A command-line interface (CLI) like PowerShell lacks those kinds of graphical discoverability features, but consistency can provide a kind of discoverability of its own. For example, let s say I told you that the cmdlet verb Get was used for all cmdlets that retrieve or display something (as with Get-Content). You already know that cmdlet

nouns are singular, and never plural. Can you guess the names of the cmdlets that would perform the tasks in table 2.3

Table 2.3 Guessing the cmdlet names for specific tasks Task Display a list of services Display a list of running processes Display the contents of an event log Create a new service Retrieve Exchange mailboxes Create a new Exchange mailbox Cmdlet

All of those tasks can be accomplished with one of two verbs: Get or New. From there, you just have to make an educated guess about the noun. The right answers are shown in table 2.4.

Table 2.4 Introducing some new cmdlets Task Display a list of services Display a list of running processes Display the contents of an event log Create a new service Retrieve Exchange mailboxes Create a new Exchange mailbox Get-Service Get-Process Get-EventLog New-Service Get-Mailbox New-Mailbox Cmdlet

The last two cmdlets in table 2.4 aren t native to PowerShell, and you won t be able to try them unless you have the Exchange Server 2007 (or 2010) add-in loaded, which isn t something we re going to cover just now. The point for right now is guessing the right cmdlet name if you were able to do that, then you re well on your way to mastering the shell. More importantly, don t ever be afraid to guess a cmdlet name, and don t be afraid to be wrong. In the next chapter, I ll show you how to check and see if your guesses are correct, and how to teach yourself how to use a cmdlet once you ve discovered its name. I ll also show you how to search for cmdlets based on a part of their name, which can be another useful trick for discovering new cmdlets.