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Can a Macintosh person tell us how to change the name of a file?
"Tim Streater" wrote
| The type of a file and which app you'd like it to open with are items | of file metadata and have no business being part of the filename. | Many files have such type-identifiers included. E.g., a JPG file begins | with JFIF, a WordPerfect file includes WPC in the first line, an MS .doc | Then you've put the metadata inside the file, which is even worse. It | should be part of the file system. This is the problem with mixing Mac and Windows discussions. As I understand it, Mac stores file data separately as a "resource fork". Mac users are not expected to understand anything about files. That's not the same as metadata. Resource fork used to be a problem when Mac users emailed photos. If they didn't know to strip the Mac- specific prepended data they'd send a corrupt file. Mac file data: File info stored separately from the file, only on Macs. File signatu Sometimes called "magic" or "magic bytes" -- beginning bytes that *sometimes* identify a file type. For instance, a BMP bitmap file starts with hex 42 4D, which in ASCII encoding is "BM". A TXT text file, on the other hand, usually won't have any header at all. It *might* have a marker if it's unicode-encoded. File headers are data about the file structure, appearing at the beginning of the file. Headers, or lack of them, vary widely with file types. BMP header is very simple. TXT has none. JPG can be extensive, even including a small thumbnail image. There's no rule about the need for headers and even when there are headers the rules are sometimes flexible. Metadata: Optional file info stored in a file header. Some of it is standard to the file format. Some is added. For example, everyone and his brother has made up data markers to store in JPG files. None of it has to be there. Some of it is unofficial and not widely supported. It's been established willy nilly as JPG has become widely used. On the other hand, the file header of PE files (portable executable EXE, DLL, OCX) is strictly defined to detail things like imported dependencies, exported functions, embedded strings and other resources, etc. You don't need to "open" a file to see what type it is, in the sense that you don't have to run it. The hex editor HxD is free and very good. You can put an Open With HxD on your right-click menu and look at the file bytes to see what it is. Here's a guide: https://www.garykessler.net/library/file_sigs.html If you're on a Mac and this is not relevant to you then stop crossposting to a Windows group. |
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