.\" Copyright 2020, Michael Kerrisk <mtk.manpages@gmail.com>
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH intptr_t 3type 2026-02-08 "Linux man-pages 6.17"
.SH NAME
intptr_t, uintptr_t \- integer types wide enough to hold pointers
.SH LIBRARY
Standard C library
.RI ( libc )
.SH SYNOPSIS
.nf
.B #include <stdint.h>
.P
.BR typedef " /* ... */ " intptr_t;
.BR typedef " /* ... */ " uintptr_t;
.P
.BR "#define INTPTR_WIDTH" "  /* ... */"
.B #define UINTPTR_WIDTH INTPTR_WIDTH
.P
.BR "#define INTPTR_MAX" "    /*  2**(INTPTR_WIDTH \- 1) \- 1  */"
.BR "#define INTPTR_MIN" "    /*  \- 2**(INTPTR_WIDTH \- 1)    */"
.BR "#define UINTPTR_MAX" "   /*  2**UINTPTR_WIDTH \- 1       */"
.fi
.SH DESCRIPTION
.I intptr_t
is a signed integer type
such that any valid
.RI ( "void *" )
value can be converted to this type and then converted back.
It is capable of storing values in the range
.RB [ INTPTR_MIN ,
.BR INTPTR_MAX ].
.P
.I uintptr_t
is an unsigned integer type
such that any valid
.RI ( "void *" )
value can be converted to this type and then converted back.
It is capable of storing values in the range
.RB [ 0 ,
.BR UINTPTR_MAX ].
.P
The macros
.RB [ U ] INTPTR_WIDTH
expand to the width in bits of these types.
.P
The macros
.RB [ U ] INTPTR_MAX
expand to the maximum value that these types can hold.
.P
The macro
.B INTPTR_MIN
expands to the minimum value that
.I intptr_t
can hold.
.P
The length modifiers for the
.RI [ u ] intptr_t
types
for the
.BR printf (3)
family of functions
are expanded by the macros
.BR PRIdPTR ,
.BR PRIiPTR ,
and
.B PRIuPTR
(defined in
.IR <inttypes.h> );
resulting commonly in
.B %"PRIdPTR"
or
.B %"PRIiPTR"
for printing
.I intptr_t
values.
The length modifiers for the
.RI [ u ] intptr_t
types
for the
.BR scanf (3)
family of functions
are expanded by the macros
.BR SCNdPTR ,
.BR SCNiPTR ,
and
.B SCNuPTR
(defined in
.IR <inttypes.h> );
resulting commonly in
.B %"SCNuPTR"
for scanning
.I uintptr_t
values.
.SH STANDARDS
.TP
.RI [ u ] intptr_t
.TQ
.RB [ U ] INTPTR_MAX
.TQ
.B INTPTR_MIN
C23, POSIX.1-2024.
.TP
.RB [ U ] INTPTR_WIDTH
C23.
.SH HISTORY
.TP
.RI [ u ] intptr_t
SUSv2,
C99,
POSIX.1-2001 XSI.
.TP
.RB [ U ] INTPTR_MAX
.TQ
.B INTPTR_MIN
C99,
POSIX.1-2001 XSI.
.TP
.RB [ U ] INTPTR_WIDTH
C23.
.SH NOTES
The following header also provides these types:
.IR <inttypes.h> .
.SH SEE ALSO
.BR intmax_t (3type),
.BR void (3)