Ruby download a file from base url

To solve all of this, Janko created the Down gem. It allows you to avoid these issues to safely and efficiently download files. We can download the image to a Tempfile using Down. If you want to save this file to the file system, Down has an option for that. Passing a directory as a :destination option will save the file to that directory. This will give the downloaded file a random name generated by Tempfile.

If you want to keep the name of the file from the URL you need to do a bit more work. In this case we can download the file to a Tempfile and then move it to a permanent location on our drive. The Regexp object returned by this method includes arbitrary number of capture group parentheses. Never rely on its number.

Home Core 3. Home Classes Methods. You can find your desired encoding on the fly by sending encoding to your file contents string. Or if you're using an IO-object, you can call io. By default, files created with Tempfile. This can pose problems for applications or tools like Carrierwave and soffice that rely on a file's extension to perform their operations. In these cases, you can pass an extension to the Tempfile initialization as demonstrated above in Anatomy of Tempfile new.

If you need to dynamically determine your file's extension, you can usually grab it from the URL or file path you are reading into your Tempfile:. Many developers use local file storage for their development environment. In these cases, local file paths often appear in methods that are expecting URLs. Not fun. Jirapong Levi Levi 4, 1 1 gold badge 16 16 silver badges 15 15 bronze badges.

This works. I tried this on an image. The image was not properly written to the file. As if it has been corrupted or something. Also could you guide me to do this same in a Rails application.

Can i use this in a Rails application? Yes, you can use it in a rails application. The file not being written properly is probably because I forgot to open the destination in write-binary mode. I'll edit that now. This reads the whole file in memory. The best way is IO. Show 3 more comments. Abram KrauseFx KrauseFx 11k 6 6 gold badges 44 44 silver badges 52 52 bronze badges.

This reads the whole file into memory before writing it to disk, so That said, if you're OK with that, a shorter version assuming url and filename are in variables url and file , respectively , using open-uri as in the first: File.

Dead simple, for the trivial download case. Expanding on Dejw's answer edit2 : File. Sorry, but I don't know a more elegant way of having Ruby wait for the buffer to fill. Edit: This is a version that automatically adjusts itself to keep the buffer just at or below capacity. Isa Isa 1 1 silver badge 3 3 bronze badges. Rolf Rolf 39 1 1 bronze badge.

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