NAME

htonl, htons, ntohl, ntohs — convert values between host and network byte order

SYNOPSIS

#include <arpa/inet.h>

uint32_t htonl(uint32_t hostlong);
uint16_t htons(uint16_t hostshort);
uint32_t ntohl(uint32_t netlong);
uint16_t ntohs(uint16_t netshort);


DESCRIPTION

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 macros.

The uint32_t and uint16_t types are defined in <inttypes.h>.

RETURN VALUE

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.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

These functions are most often used in conjunction with IPv4 addresses and ports as returned by gethostent() and getservent().

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

be16toh, endhostent, endservent

XBD <arpa/inet.h>, <endian.h>, <inttypes.h>

CHANGE HISTORY

First released in Issue 6. Derived from the XNS, Issue 5.2 specification.

Issue 8

Austin Group Defect 162 is applied, adding be16toh() and <endian.h> to the SEE ALSO section.