10

I added a torrent for download about a month ago which is in .rar format. Unfortunately, it doesn't seem to proceed any further than 91.01% due to unavailability of seeders.

Whenever I try to open or extract the torrent I get the following error:

An error occurred while loading the archive.

Command Line output:

??? - the file header is corrupt.

I am using archive manager to extract the file. Is there any possibility of extracting the file using any method?

LiveWireBT
  • 28,763
Jitendra
  • 185
  • 2
  • 4
  • 16

2 Answers2

23

First, if the header is corrupted or the header is password protected and you don't know the password, the program has no information about the content of the archive and is therefore unable to extract files.

Extracting with unrar and the keep broken extracted files option sometimes works, but it depends on the archive contents.

unrar x -kb example.rar

Advice for sharing files: Avoid zipping¹, nested zipping², splitting³, remuxing⁴, etcetera.

1. Avoid zipping, because it might actually be nested zipping or nested compression. Many modern formats like Office Open XML (DOCX) and OpenDocument (ODF) are already compressed. The bits and energy you think you can save and be considerate about the environment will go to waste when the many machines between you and the recipient try to be smart and protect people by unpacking and checking everything, which some do. It also generates false positives and it may be annoying for the recipient on a device that cannot handle a particular compression algorithm. I know that makes me sound a bit grumpy, zip has been just fine, until you research how the many compression formats evolved, what kind of modern features did not succeed and you remember early modern devices which struggled with GIF, PDF and so much more. Just keep it simple and people happy by not burdening them with a lot of complexity. :-) 2. Nested zipping or nested compression does not improve compression, it makes it worse. Some encoders and algorithms try to be smart and decide not to compress already compressed content any further. That's the way to technical explanation, the simple explanation is: It's annoying and time consuming. 3. Avoid splitting if you don't have to. I've seen many implementations and workarounds over the years which puzzled other people, including me when I was much younger. Keep it simple when you can. 4. That's more from a video encoding nerd point of view and having to deal with e-mail, malware and fax transmission analysis in a previous job. I could send you awkward video files with actual documents in them when you are in a hurry and you just need that one important document. But I try to be a nice guy, so I don't do that and I expect others to be nice too.
LiveWireBT
  • 28,763
  • Could you please explain your advice for sharing files. May be 1 line of explanation behind each point? – Porcupine Mar 15 '22 at 16:36
  • @Porcupine I tried. :-) But I'm not happy with the result. – LiveWireBT Apr 09 '22 at 16:04
  • Why do you seem unsatisfied? A good answer should substantiate the reasoning behind points. If someone understands the reasoning clearly, they are going to take your points more seriously. – Porcupine Apr 09 '22 at 21:34
  • Zipping comprises of archiving and compressing. Are you also against archiving? It helps to send hierarchical files in a folder structure and also, its easier to handle when there are lots of files. – Porcupine Apr 09 '22 at 22:15
  • My advice was to keep it simple whenever possible. If you send a support file which is just an archive of configuration files and logs to a vendor or helpdesk, then they know what to expect and they can handle it just fine. Don't modify it, no unpacking and not further archiving or compression. Situations where the RAR format is involved are a particular kind of groupthink and how to use computers which is contradictory to open source. Sorry I think I'm heading in a wrong direction here, which is why I was absolutely fine with the initial short version of my answer. – LiveWireBT Apr 15 '22 at 09:09
0

If the incomplete rar archive is part of a series of multiple archives belonging to the same group it is possible to extract the individual parts, but only starting with the first archive until a missing archive is not found, and then the remainder of the extraction will not be successful. The extracted parts will be located in a hidden folder. Press the keyboard combination Ctrl+H or select View -> Show Hidden Files in Files file browser to show that hidden folder.

karel
  • 114,770