From: utzoo!decvax!cca!sdyer@Bbn-Unix@sri-unix
Newsgroups: net.unix-wizards
Title: Re: Information on Unix/Vax peculiarities
Article-I.D.: sri-unix.4840
Posted: Wed Dec 15 03:35:51 1982
Received: Sat Dec 18 22:36:51 1982

From: Steve Dyer <sdyer@Bbn-Unix>
Date:  9 Dec 1982 16:59:52 EST (Thursday)
V5 and early V6 (pre-Phototypesetter distribution) C compilers
had no concept of a 'long' integer.  Rather, most programs used
a set of library routines, and passed int[2] objects to them.
The kernel was full of these, particularly in the manipulation
of variables representing UNIX time.

The unusual calling sequence for time(), i.e.

	long tvec;	reflects the V6			 int tvec[2];
	time(&tvec);	    construct			 time(tvec);

which was kept for compatibility with earlier C programs.  In V7,
they also redeclared it as returning a 'long' quantity, so that new
programs could use the more natural convention.

In the same sense, one could say that the calling sequence for
the newer V7 call, ftime(struct timeb *), reflects the very late
addition of structures as legal return values to the C language.
That is, they had the option of declaring ftime() to return a timeb
structure, but they didn't (probably for backward compatibility.)

/Steve Dyer