'\" et
.TH HTONL "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
htonl,
htons,
ntohl,
ntohs
\(em convert values between host and network byte order
.SH SYNOPSIS
.LP
.nf
#include <arpa/inet.h>
.P
uint32_t htonl(uint32_t \fIhostlong\fP);
uint16_t htons(uint16_t \fIhostshort\fP);
uint32_t ntohl(uint32_t \fInetlong\fP);
uint16_t ntohs(uint16_t \fInetshort\fP);
.fi
.SH DESCRIPTION
These functions shall convert 16-bit and 32-bit quantities between
network byte order and host byte order.
.P
On some implementations, these functions are defined as macros.
.P
The
.BR uint32_t
and
.BR uint16_t
types are defined in
.IR <inttypes.h> .
.SH "RETURN VALUE"
The
\fIhtonl\fR()
and
\fIhtons\fR()
functions shall return the argument value converted from host to
network byte order.
.P
The
\fIntohl\fR()
and
\fIntohs\fR()
functions shall return the argument value converted from network to
host byte order.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH "EXAMPLES"
None.
.SH "APPLICATION USAGE"
These functions are most often used in conjunction with IPv4 addresses
and ports as returned by
\fIgethostent\fR()
and
\fIgetservent\fR().
.SH "RATIONALE"
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIendhostent\fR\^(\|)",
.IR "\fIendservent\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<arpa_inet.h>\fP",
.IR "\fB<inttypes.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .