Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!snorkelwacker!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: log10(8)
Message-ID: <16036@haddock.ima.isc.com>
Date: 26 Feb 90 20:29:32 GMT
References: <3244@servax0.essex.ac.uk> <1990Feb26.031254.11354@cubmol.bio.columbia.edu> <90057.130433CMH117@psuvm.psu.edu>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 16

In article <90057.130433CMH117@psuvm.psu.edu> CMH117@psuvm.psu.edu (Charles Hannum) writes:
>You may also have to change the printf() to:
>   printf("%lf", l);

No.  "%f" is the correct printf format for double; "%lf" is undefined.
Backward compatibility strikes again.

(In an ideal world, the three floating-point sizes would be called "short
float", "float", and "long float", and their printf/scanf formats would be
"%hf", "%f", and "%lf".  Unfortunately, for historical reasons the types are
"float", "double", and "long double", their scanf formats are "%f", "%lf", and
"%Lf", and their printf formats are <none>, "%f", and "%Lf".  There is no
printf format for float, since one cannot directly pass floats by value to a
variadic function.)

Karl W. Z. Heuer (karl@ima.ima.isc.com or harvard!ima!karl), The Walking Lint