diff options
| -rw-r--r-- | share/man/man9/style.9 | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/share/man/man9/style.9 b/share/man/man9/style.9 index 89976d6489fa..e05a6f9568e6 100644 --- a/share/man/man9/style.9 +++ b/share/man/man9/style.9 @@ -13,7 +13,7 @@ files in the FreeBSD source tree. * * @(#)style 1.14 (Berkeley) 4/28/95 * - * $Id: style.9,v 1.7 1996/04/07 08:37:54 mpp Exp $ + * $Id: style.9,v 1.8 1996/06/13 19:52:42 wollman Exp $ * */ @@ -278,8 +278,16 @@ the declarations. Use this feature only thoughtfully. .Ed .Pp Casts and sizeof's are not followed by a space. -Also, test pointers -against NULL, i.e. use: +.Pp +NULL is the preferred null pointer constant. Use NULL instead of +(type *)0 or (type *)NULL in contexts where the compiler knows the +type, e.g., in assignments. Use (type *)NULL in other contexts, +in particular for all function args. (Casting is essential for +varadic args and is necessary for other args if the function prototype +might not be in scope; since we pretend to support K&R compilers, +most prototypes might not be in scope.) +Test pointers +against NULL, e.g., use: .Bd -literal -offset 0i (p = f()) == NULL .Ed @@ -309,7 +317,7 @@ or don't roll your own! .Bd -literal -offset 0i if ((four = malloc(sizeof(struct foo))) == NULL) - err(1, NULL); + err(1, (char *)NULL); if ((six = (int *)overflow()) == NULL) errx(1, "Number overflowed."); return (eight); |