On Wed, Jun 19, 2013 at 6:58 PM, Alan Gauld <alan.ga...@btinternet.com> wrote: > On 19/06/13 17:41, Jim Mooney wrote: > >> you should use forward slashes. I have no idea why Bill Gates thought >> backslashes were kewl > > Because MS DOS was copying CP/M which didn't have directory paths > (it was used with 180K floppy disks that stored everything at the top > level) but did have command options that were indicated by a > forward slash > > DIR /S > > was a sorted directory listing etc. > > So MS DOS inherited / as an options marker which precluded > it's later use as a path separator...
CP/M didn't have a hierarchical file system, but it did have up to 16 USER areas. As to / switches, maybe at some point someone confused CP/M with DEC's TOPS-10, which used switches quite a lot (it even had SWITCH.INI for defaults). TOPS-10 would have been familiar to many 1970s programmers. Its DIR command had over 70 switches, such as /SORT (default) and /NOSORT. In contrast, DIR on CP/M used options in square brackets, such as the following example: DIR [DRIVE=B,USER=ALL,EXCLUDE,NOSORT] *.DAT This would list all files on B: in all USER areas exluding DAT files, without sorting. The USER areas in CP/M are reminiscent of TOPS-10 user-file directories. A UFD was designated by a [project, programmer] number (PPN), and could have up to 5 levels of sub-file directories (SFD). For example, DSKB:FOO.TXT[14,5,BAR,BAZ], where 14,5 is a PPN. In VMS style it's DSKB:[USER.BAR.BAZ]FOO.TXT. In comparison, slash vs. backslash seems trivial. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
