Powershell download files from multiple websites

Be aware of this Powershell gotcha - use spaces when calling a function with multiple arguments. Let's investigate the function a bit closer. As you can see, although Powershell allows mutable types which means that a variable containing for example a string can be redefined to an integer , prefixing the arguments with square brackets and a type, such as [Object[]] or [string] , makes your Powershell scripts more type-safe.

Powershell obviously in many cases feels like Javascript for example, where also a variable can be changed into another type redefined. If you want to have more type safety, prefix your function arguments with the strongly type you expect being passed into the Powershell function. To perform the download of each file in the passed in Object Array , I use a foreach loop.

This is where Powershell shows itself as a convenient scripting language. Iterating through a collection using foreach loop makes coding much easier, note though that Perl already implemented this functionality some years ago. DownloadFile downloads the file from the Internet using the instantiated WebClient. I am not sure if. BAT files could achieve this, but this shows how much functionality is available to Powershell users and Developers.

Powershell is well suited for system maintenance and administration, plus actually are larger part of target uses than one might think of a shell script language and command line tool.

The fact that much of. NET is available means that. NET Developers in some cases must rethink their use of the relationship between compiled programs and scripts, now that Powershell is so available. The added convenience and flexibility of Powershell, plus functionality makes Powershell a contender among the more mature. If you implemement something in a Programming language, think of doing the same in a script. Sometimes going for a script based solution will be better, more flexible and optimal.

For developers using. NET methods and types are available for us in Powershell. To start the PowerShell script, I type. More commands can be aliased, such that Unix Developers can manage part of Windows Clients and servers and still have that familiar Unix syntax feel of it You can see this under the comment "change filename in order to prevent overwriting of log file".

I suspect there was a much more intuitive way to do this and I would just love it if someone chimed in with a better way to do this as its driving me crazy that I don't know a better way. It should be noted that there are a total of 44 urls where I'm downloading from, hence the magic numbers 11, 22, 33 where I change the host name. Again, if you know a better way please don't hesitate to let me know.

I should of had these to start with as by not having them before I was assuming that the script was always going to work. Rookie mistake and point taken. With that being said, these are all my edits. The code is working fine, but improvement is always possible. Thank you for your time and answers. Invoke-WebRequest is a good way in Powershell to download files and the OutFile parameter will put this straight to disk, docs are here.

It is actually one whole string. Try something like this instead:. The variable will expand in that string just fine. The issue before is that you were concatenating the string starting from the first part because of the order of operations.

When you add an array to a string on the left hand side the array gets converted to a space delimited string. Have a look at a smaller example which is exactly what you tried to do. This code might make sense elsewhere but as others have pointed out you have a useless loop about lines in a file. If you don't use it get rid of it.

If you are going to use the working directory of the script at least use some absolute paths. Side note the comments don't really match what is happening which is likely related to 2. You should try and make that unique somehow since the files will overwrite eachother as you have it coded. I would also wrap that in a try block in case the download fails and you can report properly on that. As of now you assume it will work every time.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Refer to the demo below to see how the code above works. As you can see, the download starts, and you see the download progress. The PowerShell prompt is not available during the download process. Suppose you want to start the download process as a background job. To do so, you only have to add the -Asynchronous switch at the end of the Start-BitsTransfer command.

Initially, the state of each job would show c onnecting. To check the download job status, use the Get-BitsTransfer cmdlet. PowerShell is based on. NET, and its nature makes it capable of leveraging the power of. NET itself. If you want to know more about these two. HttpClient vs. To use the WebClient class, you need to initiate an object as a System. WebClient object. Then, using the DownloadFile method starts the download of the file from the source.

Please copy the code below and run it in your PowerShell session to test. However, the PowerShell prompt will be locked until the download is complete. If the source requires authentication to allow the file download, you can use the code below. Instead, use the System. HttpClient class. It appears that the WebClient class is obsolete, and the new class that Microsoft is endorsing is the HttpClient class.

The next section talks about using the HttpClient class in PowerShell to download files from the web. Like the WebClient class, you need to create first the System. Refer to the comments above each line to know what each line of code does.

In situations where downloading a file requires authentication, you need to add the credential to the HttpClient object. To include a credential to the file download request, create a new System. HttpClientHandler object to store the credentials.

You can copy the code below and run it in PowerShell to test. Or you can also run it as a PowerShell script. In this example, the code is saved as download-file. At the start, the directory only has the script file in it. Then, the script proceeds to download the file.