* 白熊 <guile-user_gnu....@sumou.com> [2014-08-05 03:56:03+0400] > Also, is there a way to determine the exact file size, so I could > check before downloading, if the file has already been downloaded, > i.e. same size on disk as on the web, or if the prior download failed, > i.e. smaller size on disk, than the web? > > I thought the headers would have the size info of the tarball, but I see no > such information in res-headers... > > But surely, the information must be available as any download tool > like wget or a browser is able to determine the download file size.
Seems that wget also do not have this information. wget -S http://hackage.haskell.org/package/HaTeX-2.1.3/HaTeX-2.1.3.tar.gz --2014-08-05 11:27:59-- http://hackage.haskell.org/package/HaTeX-2.1.3/HaTeX-2.1.3.tar.gz Resolving hackage.haskell.org (hackage.haskell.org)... 88.198.224.242, 88.198.224.242 Connecting to hackage.haskell.org (hackage.haskell.org)|88.198.224.242|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 200 OK Server: nginx/1.6.0 Date: Mon, 04 Aug 2014 16:53:31 GMT Content-Type: application/x-gzip Content-MD5: c4d3cf03316068d1ef0799024f6a1dfd ETag: "c4d3cf03316068d1ef0799024f6a1dfd" Last-Modified: Fri, 22 Oct 2010 21:18:12 GMT Age: 52477 Transfer-Encoding: chunked Connection: keep-alive Length: unspecified [application/x-gzip] Saving to: `HaTeX-2.1.3.tar.gz' Look, it says, that length is unspecified. My best bet is use #:streaming? flag to `http-get` to examine headers before downloading, and if I decide to download, get data from port via `get-bytevector` function family. This way you also can examine first several bytes before decide, whether file is needed, if headers information is not sufficient. -- Best regards, Dmitry Bogatov <kact...@gnu.org>, Free Software supporter, esperantisto and netiquette guardian. GPG: 54B7F00D
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