I was curious where the RISC OS `device.path.leads.to.file` style path format came from. Apparently it came from the classic IBM OSes.
Multics >device>path>leads>to>file.ext Unix /device/path/leads/to/file.ext MIT ITS device:path;leads;to;file ext extension is separate from filename Amiga device:path/leads/to/ext.file extension comes first CP/M device:\path\leads\to\file.ext DOS device:\path\leads\to\file.ext yes, MS "borrowed" a lot from CP/M MacOS device:path:leads:to:file.txt System 1 to Mac OS9 VMS device:[path.leads.to]file.ext also allows ext.gen - versioning TOPS-20 device:<path.leads.to>file.ext also allows ext.gen - versioning TENEX device:<path.leads.to>file.ext IBM zOS device.path.leads.to.file.ext RISC OS device.path.leads.to.file extension is separate from filename DOS files .ext is renamed to /ext while ROS files get ,HEXCODE suffix when transferred to DOS or over network, without MIME types.
Note that VMS/TOPS-20/zOS/RISC OS allow several named root dirs for a device. I.e. single device could have several filesystems.
Typically they are specified as DEVICE$FILESYSTEM
So basically, the `.` format comes from IBM. Unsure if the `.` in C based language was also based on it.