att & osf

Barry Shein bzs at encore.UUCP
Sun Aug 21 06:10:11 AEST 1988


Henry Spencer writes...
>Well, actually, it can in various ways.  To take a small example, consider
>the vile botch in System V interprocess communication of using -1 (rather
>than 0) cast to a pointer as an error return code.  That is *not* portable,
>but it happens to work on certain architectures.

Far be it for me to defend anyone, but this stems from a day-one bug
that predates all of this (at least V6, probably earlier.)

Consider that sbrk() returns -1 (specifically, (char *)-1) as an error
code in all Unix's I know of (BSD, SYSV.)

Real problem of conventions, should syscalls always try to return -1?
Unfortunate convention!

	-Barry Shein, ||Encore||



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