"Show information" command
This command is accessible both when WinRAR is in the file management and in the archive management modes. Just run "Show information" command using either Tools menu, "Info" button on the toolbar or Alt+I keyboard shortcut.
In the file management mode it allows to get the information about contents of selected files and folders: the total size, a number of files and subfolders, a number of archives. To improve the operation speed archives are detected basing only on the file name extension, so self-extracting archives are not counted here. File scanning may take a long enough time, but if you wish you may close the dialog in any moment.
Disk space is allocated to files in fixed size blocks called clusters. For example, if a cluster size is 4096 bytes and you created a file only 1 byte size, in fact it will occupy 4096 bytes. So, to give you a hint, how much space your files are really take and how much you may save after archiving them, the information dialog also displays a cluster size for the current disk, a real size of selected files including not filled tails of clusters and so called "Files slack" - the total space wasted in these cluster tails.
When the file scanning is complete, you may press "Estimate" button to get a prognosis about compression size and time of selected files. Note that the compression estimation is performed very quickly and very roughly, so do not expect an exact result here. Though it can show if it is worth spending time to compress selected data. If you set "Start automatically" option before closing the dialog, when you open the dialog next time, the estimate operation will be initiated automatically, without necessity to use "Estimate" button.
Also, after completing the scan operation, it is possible to switch to other pages of this dialog and specify different archive options like a comment, recovery record, SFX module, etc. It allows to apply necessary changes to all RAR and ZIP archives contained in the selected folders and files. Unlike the scan step, self-extracting archives are also processed here. Be cautious with this operation, it may change parameters of hundreds and thousands archives at once. Such feature is powerful, but may become rather dangerous when improperly used.
In the archive management mode, when you activate "Show information" either inside of archive or outside of it, but when only one archive is selected, WinRAR will display the following information about the archive:
For RAR volumes created by WinRAR 3.40 or higher this string also includes a volume number. This number may be useful if original volume names are lost and you need to restore correct names manually;
If the archive has an archive comment, an additional dialog sheet containing this comment is displayed.
Like in the file management mode, it is possible to switch to other pages of the dialog and specify different parameters for the current archive. Just press "Help" button in other pages to read more about them.