Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!talcott!harvard!seismo!brl-tgr!gwyn From: gwyn@brl-tgr.ARPA (Doug Gwyn) Newsgroups: net.bugs.4bsd Subject: Re: libm---log(negative) Message-ID: <8190@brl-tgr.ARPA> Date: Sun, 10-Feb-85 16:28:49 EST Article-I.D.: brl-tgr.8190 Posted: Sun Feb 10 16:28:49 1985 Date-Received: Tue, 12-Feb-85 05:54:07 EST References: <130@entropy.UUCP> Distribution: net Organization: Ballistic Research Lab Lines: 10 > Anyway, does anyone, > besides me, think it would be a good idea to explicitly warn the user > when s/he attempted to call log with a negative argument? If so, > have you come up with a smooth way of doing it? Yes, on UNIX System V there is a matherr(3M) library function that is invoked when a math library routine detects an error. By default it prints an appropriate warning message on stderr. The programmer can provide his own matherr() and do whatever he thinks is appropriate upon occurrence of a math library error.