| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
| .\" preserved on all copies. |
| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
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| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" %%%LICENSE_END |
| .\" |
| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 21:29:05 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified Thu Jul 26 14:06:20 2001 by Andries Brouwer (aeb@cwi.nl) |
| .\" |
| .TH BYTEORDER 3 2017-09-15 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| htonl, htons, ntohl, ntohs \- convert values between host and network |
| byte order |
| .SH SYNOPSIS |
| .nf |
| .B #include <arpa/inet.h> |
| .PP |
| .BI "uint32_t htonl(uint32_t " hostlong ); |
| .PP |
| .BI "uint16_t htons(uint16_t " hostshort ); |
| .PP |
| .BI "uint32_t ntohl(uint32_t " netlong ); |
| .PP |
| .BI "uint16_t ntohs(uint16_t " netshort ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR htonl () |
| function converts the unsigned integer |
| .I hostlong |
| from host byte order to network byte order. |
| .PP |
| The |
| .BR htons () |
| function converts the unsigned short integer |
| .I hostshort |
| from host byte order to network byte order. |
| .PP |
| The |
| .BR ntohl () |
| function converts the unsigned integer |
| .I netlong |
| from network byte order to host byte order. |
| .PP |
| The |
| .BR ntohs () |
| function converts the unsigned short integer |
| .I netshort |
| from network byte order to host byte order. |
| .PP |
| On the i386 the host byte order is Least Significant Byte first, |
| whereas the network byte order, as used on the Internet, is Most |
| Significant Byte first. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lbw34 lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR htonl (), |
| .BR htons (), |
| .BR ntohl (), |
| .BR ntohs () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008. |
| .PP |
| Some systems require the inclusion of |
| .I <netinet/in.h> |
| instead of |
| .IR <arpa/inet.h> . |
| .SH SEE ALSO |
| .BR bswap (3), |
| .BR endian (3), |
| .BR gethostbyname (3), |
| .BR getservent (3) |