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man iwr Oh, there's an OutFile parameter. Let's see what it does man iwr -param outfile How nice, it writes the response directly to a file instead of to

by ygra 10y ago

man iwr Oh, there's an OutFile parameter. Let's see what it does man iwr -param outfile How nice, it writes the response directly to a file instead of to the pipeline. The curl alias actually points to the very same cmdlet. Not to excuse bad examples on the internet (there are lots of people who fail to grasp PowerShell and still try to write articles and how-tos), but PowerShell having built-in documentation for commands and parameters is actually fairly easy to figure out from within the shell. Admittedly, once you learn the basic half dozen or so cmdlets you tend to use all the time. You're free to ask me (or on SO, I tend to answer PowerShell questions there) if you're having trouble. Figuring above out took literally just 20 seconds. Really. I'm kinda sick of people cursing and blaming tools just because they're different from what they're used to. If I did the same and complained about bash and Unix (which I rarely find the need or time to learn) I'd be tarred and feathered in seconds ...

xenophonf 10y ago
To be fair there are many, many examples of downloading files using System.Net.WebClient. In fact that is how the first several search results for `powershell download file` tell you to do it despite Invoke-WebRequest being included in PowerShell since 2012. `get-help download` doesn't return anything useful. Contrast that with `apropos download`, which at least on FreeBSD includes wget in the search results.
setq 10y ago
It doesn't work for large files. Try iwr with outfile on a 16Gb file on a 4/8Gb machine. Knowing all the edge cases, exceptions and places where reality breaks down is the problem. Where software should indeed work with the principle of least surprise, Microsoft have patented the principle of most inconvenient surprise. Also SO has one small comment about this which didn't exist when I discovered it. I had to use windbg to dump the CLR heap and find out that there were a crap ton of buffers... And that's every day using powershell. It's even worse if you trip over someone else's cmdlets which aren't aware of the correct harry potter style incantations to issue that don't cause the universe to implode. The whole thing is a joke. A bad one.
- ygra 10y ago
  Unless you also write things to the pipeline via -PassThru specifying -OutFile will read in 10K chunks and write them to the file. No memory apart from that buffer is used. Look at the source, it's public. My PowerShell instance uses 38 MiB of memory the whole time during the download, regardless of the file size.
  - setq 10y ago
    What's in your $PSVersionTable? I'm doing this on windows 2008 server.
    - ygra 10y ago
      5.1 on Windows 10. Admittedly, I never really tried iwr on older versions. Heck, the last time I tried downloading something with PowerShell to a file I went the WebClient.DownloadFile route, so it's been a while. You can probably install a more recent version of WinRM on that machine, though (or by now probably the open-source version of PowerShell).

by ygra 10y ago

xenophonf 10y ago

To be fair there are many, many examples of downloading files using System.Net.WebClient. In fact that is how the first several search results for `powershell download file` tell you to do it despite Invoke-WebRequest being included in PowerShell since 2012. `get-help download` doesn't return anything useful. Contrast that with `apropos download`, which at least on FreeBSD includes wget in the search results.

setq 10y ago

It doesn't work for large files. Try iwr with outfile on a 16Gb file on a 4/8Gb machine. Knowing all the edge cases, exceptions and places where reality breaks down is the problem. Where software should indeed work with the principle of least surprise, Microsoft have patented the principle of most inconvenient surprise. Also SO has one small comment about this which didn't exist when I discovered it. I had to use windbg to dump the CLR heap and find out that there were a crap ton of buffers... And that's every day using powershell. It's even worse if you trip over someone else's cmdlets which aren't aware of the correct harry potter style incantations to issue that don't cause the universe to implode. The whole thing is a joke. A bad one.

ygra 10y ago
Unless you also write things to the pipeline via -PassThru specifying -OutFile will read in 10K chunks and write them to the file. No memory apart from that buffer is used. Look at the source, it's public. My PowerShell instance uses 38 MiB of memory the whole time during the download, regardless of the file size.
- setq 10y ago
  What's in your $PSVersionTable? I'm doing this on windows 2008 server.
  - ygra 10y ago
    5.1 on Windows 10. Admittedly, I never really tried iwr on older versions. Heck, the last time I tried downloading something with PowerShell to a file I went the WebClient.DownloadFile route, so it's been a while. You can probably install a more recent version of WinRM on that machine, though (or by now probably the open-source version of PowerShell).