.TH NULL "" "" "Manifest Constant"
.PC
.PP
The manifest constant
.B NULL
is defined in the header file
.BR stddef.h .
It is the null pointer \fB(char *)0\fR, which is a
pointer initialized to zero.
Numerous routines return this value to indicate failure;
it is useful as a return value because it points nowhere,
and so removes the possibility of accidentally destroying a section of
memory after failure.
.SH "See Also"
.Xr "manifest constant," manifestc
.Xr "NUL," nul
.Xr "pointer," pointer
.Xr "stdio.h" stdio.h
.br
\*(AS, \(sc7.1.6
