Regarding the use of a temporary directory, this is so to follow many operating system guidelines. The worst thing that can happen to a page file. Paging under these circumstances would be a lot slower than just using the filesystem because the file is still being decompressed (and page files keep being added), but also because as the file is being decompressed, it is being checked for errors and there's as such a lot of read/write operations. Under low memory conditions, or for large compressed files this would sooner or later exhaust available memory and start the process of memory paging. If they didn't use the filesystem, decompression would happen in memory. It is done so memory requirements for decompression are kept to a minimum. I learned this the hard way several years ago when I wanted to implement drag-and-drop in a program I was writing. If you specify the folder and click Extract, it extracts and no further processing is done.įeel free to peruse the source-code for 7-Zip to see how extraction location is handled. When you drag it out to a folder, it extracts, then you see Explorer’s standard file operation dialog moving it to the folder. You can see this clearly by extracting a large file using both methods. As a result, the program cannot know where to extract them, and so simply extracts them to the temp folder, then Explorer moves them once it’s done. In other words, it is Explorer that receives the target folder, not the archiving program. However, if you merely drag the files, then due to how the drag-and-drop function of OLE works, the program does not know where the target folder is. If you enter the target folder or use the context-menu item, then the program knows exactly where it needs to extract to. The reason is in how the destination is selected. If you select the files in the UI and drag them to the target folder, then it will extract to a temporary folder.

If you enter a destination folder and then select the extract function or use the shell-extension, then they do not extract to a temporary folder first, they extract directly to the destination. How exactly are you extracting the files? Are you using the command-line or the GUI? Are you dragging the files or selecting them and using the extract function? Are you using the shell-extension context-menu?

Winzip 7