.TH "typedef" "" "" "C Keyword"
.PC "Define a new data type"
.PP
.B typedef
is a C facility that lets you define new data types.
Such definitions are always made in terms of existing data
types; for example,
.DM
	typedef long time_t;
.DE
.PP
establishes the data type \fBtime_t\fR, and defines it
to be equivalent to a \fBlong\fR.
By convention, programmer-defined data types are
written in capital letters.
.PP
Judicious use of the
.B typedef
facility can make programs easier to maintain, and improve their
portability.
.SH "See Also"
.Xr "C keyword," c_keyword
.Xr "manifest constants," manifestc
.Xr "portability," portabili
.Xr "storage class" storage_c
.br
\*(AS, \(sc6.5.6
