rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel I generally don't use NULL and use plain 0 instead, based on a "NULL considered harmful" discussion on the classiccmp mailing list many aeons ago (I couldn't find it, and I reason that it must have been 2005 or earlier), but a recent complaint by a packager sent me searching, and I found this: https://ewontfix.com/11/ While I don't give a @#$% about "modern" systems and code-nazi tools, I realized that passing a plain 0 as a pointer sentinel in execl is wrong because it will break on systems where pointers are longer than the plain int type. Again, I don't give a @#$% about the abomination of x86_64 and the like, but if anyone ever manages to port my code to something like a PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0 as a function argument where a pointer is expected most definitely won't work: if the most natural stack slot and SP alignment unit is 16 bits, fitting an int, with longs and pointers taking up two such slots, then the call stack will be totally wrong with a plain 0 passed for a pointer. Casting the 0 to (char *) ought to be the most kosher solution for the most retro systems possible.

#define	_U	01
#define	_L	02
#define	_N	04
#define	_S	010
#define _P	020
#define _C	040
#define _X	0100
#define	_B	0200

extern	const char	_ctype_[];

#define	isalpha(c)	((_ctype_+1)[c]&(_U|_L))
#define	isupper(c)	((_ctype_+1)[c]&_U)
#define	islower(c)	((_ctype_+1)[c]&_L)
#define	isdigit(c)	((_ctype_+1)[c]&_N)
#define	isxdigit(c)	((_ctype_+1)[c]&(_N|_X))
#define	isspace(c)	((_ctype_+1)[c]&_S)
#define ispunct(c)	((_ctype_+1)[c]&_P)
#define isalnum(c)	((_ctype_+1)[c]&(_U|_L|_N))
#define isprint(c)	((_ctype_+1)[c]&(_P|_U|_L|_N|_B))
#define isgraph(c)	((_ctype_+1)[c]&(_P|_U|_L|_N))
#define iscntrl(c)	((_ctype_+1)[c]&_C)
#define isascii(c)	((unsigned)(c)<=0177)
#define toupper(c)	((c)-'a'+'A')
#define tolower(c)	((c)-'A'+'a')
#define toascii(c)	((c)&0177)