On Tue 12 Nov 2024 at 05:14:50 (+0000), fxkl4...@protonmail.com wrote: > On Mon, 11 Nov 2024, David Wright wrote: > > On Tue 12 Nov 2024 at 02:47:21 (+0000), fxkl4...@protonmail.com wrote: > >> i down loaded super_program.appimage > >> on the command line i type ./super_program.appimage > >> how does my debian powered device know what to do > > > > It looks at the file signature, or "magic number", in the first few > > bytes of the file. For example, type: > > > > $ hexdump -C /bin/cat | head -n 1 > > 00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 > > |.ELF............| > > $ > > > > and the 7f 45 4c 46 sequence means Executable and Linkable Format. > > OTOH, in: > > > > $ hexdump -C /bin/firefox | head -n 1 > > 00000000 23 21 2f 62 69 6e 2f 73 68 0a 0a 46 49 52 45 46 > > |#!/bin/sh..FIREF| > > $ > > > > the first two bytes, 23 21, indicate that the file should be passed > > to the program whose name immediately follows, ie /bin/sh, which is > > normally the dash shell in Debian. > > > > See https://en.wikipedia.org/wiki/List_of_file_signatures for > > loads more magic numbers. > > i don't see anything in that about appimage
That's because the last component of the filename (aka extension) is not important in what happens when you type that command. Assuming you don't want to hear next that the device will know what to do by executing the instructions contained in the file, I'll just say that I know nothing about your appimage, so I don't know what it will cause your device to do. If you want to read about appimages and what they are in general, perhaps start at: https://en.wikipedia.org/wiki/AppImage If you want to know what super_program.appimage in particular does when you execute it, look for some documentation wherever you got it from. I would have assumed you'd already found some, which led to your downloading the file in the first place. I've written and/or used programs named super… in the dim and distant past. Typically the … bit gave /some/ indication of what the program was designed to do, like supermix and supermap. However, super_program means nothing at all to me. It sounds more like a placeholder for a program in search of a name. Cheers, David.
