carroll@snail.CS.UIUC.EDU (12/09/87)
I'm having some problems with code that need signed characters (it's
originally from a vax). Unfortunately, the machine I am on has unsigned
characters. I have not been able to find any way in C to tell the compiler to
use the characters as signed. I know that the hardware can support them, but
is there any generic way to force things to be signed? K&R has the "unsigned"
reserved word, but "signed" is not. Any help would be appreciated.
We are running SysVR3 on AT&T 3b2's, standard C.
Alan M. Carroll amc@woodshop.cs.uiuc.edu carroll@s.cs.uiuc.edu
...{ihnp4,convex}!uiucdcs!woodshop!amc
Quote of the day :
"I've consulted all the sages I could find in Yellow Pages,
but there aren't many of them" - AP & EWkarl@haddock.ISC.COM (Karl Heuer) (12/10/87)
In article <10700010@snail> carroll@snail.CS.UIUC.EDU writes: >I'm having some problems with code that need signed characters (it's >originally from a vax). Unfortunately, the machine I am on has unsigned >characters. In ANSI C, there is a keyword "signed" that does what you want. In pre-ANSI, the best way is to use a macro when you need sign-extension. Assuming 8-bit chars, the following is probably as good as anything. #if CHARS_ARE_SIGNED #define sxt(c) ((int)(c)) #else #define sxt(c) ((int)(unsigned char)((c) + 0x80) - 0x80) #endif
jal@occrsh.ATT.COM (J_Allen_Schones) (12/12/87)
In article <10700010@snail> carroll@snail.CS.UIUC.EDU writes: > > I'm having some problems with code that need signed characters (it's >originally from a vax). Unfortunately, the machine I am on has unsigned >characters. [ A few lines deleted to keep inews happy ] > > We are running SysVR3 on AT&T 3b2's, standard C. > As far as I can tell, there is no way to support signed chars on the 3BXX* line of computers. I use short ints when a signed chars is needed, but then you must check the source to make sure that the program doesn't depend upon the allowable range of chars. I F N I E L W L S E R-- J. Allen Schones -- AT&T Technologies -- Oklahoma City Works PHONE: (405) 491-4950 UUCP: ihnp4!occrsh!jal DOMAIN: jal@occrsh.ATT.COM