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.
htonl, htons, ntohl, ntohs — convert values between host and network byte
uint32_t htonl(uint32_t hostlong);
uint16_t htons(uint16_t hostshort);
uint32_t ntohl(uint32_t netlong);
uint16_t ntohs(uint16_t netshort);
These functions shall convert 16-bit and 32-bit quantities between network byte
order and host byte order.
On some implementations, these functions are defined as
The uint32_t and uint16_t types are defined in
The htonl() and htons() functions shall return the argument value
converted from host to network byte order.
The ntohl() and ntohs() functions shall return the
argument value converted from network to host byte order.
No errors are defined.
The following sections are informative.
These functions are most often used in conjunction with IPv4 addresses and ports
as returned by gethostent() and getservent().
The Base Definitions volume of POSIX.1‐2017,
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 .
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