[TUHS] v7 K&R C

Steffen Nurpmeso steffen at sdaoden.eu
Sat May 16 10:28:05 AEST 2020

Nelson H. F. Beebe wrote in
<CMM. at gamma.math.utah.edu>:
 |Discussions today on the TUHS list about the signed/unsigned nature of
 |the C char type led me to reexamine logs of my feature test package at
 | http://www.math.utah.edu/pub/features/
 |I had 170 build logs for it from 2017.11.07, so I moved those aside
 |and ran another set of builds in our current enlarged test farm.  That
 |generated another 361 fresh builds.  Those tests are all with the C
 |compiler named "cc".  I did not explore what other C compilers did,
 |but I strongly suspect that they all agree on any single platform.
 |On all but THREE systems, the tests report that "char" is signed, with
 |CHAR_MAX == +127.
 |The three outliers have char unsigned with CHAR_MAX == +255, and are
 | * ARM armv7l Linux 4.13.1 (2017) and 5.6.7 (2020)
 | * SGI O2 R10000-SC (150 MHz) IRIX 6.5 (2017 and 2020)
 | * IBM POWER8 CentOS Linux release 7.4.1708 (AltArch) (2017)
 |So, while the ISO C Standards, and historical practice, leave it
 |implementation dependent whether char is signed or unsigned, there is
 |a strong majority for a signed type.

Just to note Linus Torvalds "famous" "It better had been unsigned,

|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)

More information about the TUHS mailing list