NAME<\/a> htobe16, htole16, be16toh, le16toh, htobe32, htole32, be32toh, le32toh, htobe64, htole64, be64toh, le64toh \u2212 convert values between host and big-\/little-endian byte order<\/p>\n #include uint16_t htobe16(uint16_t<\/b> host_16bits<\/i>); uint32_t htobe32(uint32_t<\/b> host_32bits<\/i>); uint64_t htobe64(uint64_t<\/b> host_64bits<\/i>); Feature Test Macro Requirements for glibc (see feature_test_macros<\/b>(7)):<\/p>\n htobe16<\/b>(), htole16<\/b>(), be16toh<\/b>(), le16toh<\/b>(), htobe32<\/b>(), htole32<\/b>(), be32toh<\/b>(), le32toh<\/b>(), htobe64<\/b>(), htole64<\/b>(), be64toh<\/b>(), le64toh<\/b>(): These functions convert the byte encoding of integer values from the byte order that the current CPU (the “host”) uses, to and from little-endian and big-endian byte order.<\/p>\n The number, nn<\/i>, in the name of each function indicates the size of integer handled by the function, either 16, 32, or 64 bits.<\/p>\n The functions with names of the form “htobenn<\/i>” convert from host byte order to big-endian order.<\/p>\n The functions with names of the form “htolenn<\/i>” convert from host byte order to little-endian order.<\/p>\n The functions with names of the form “benn<\/i>toh” convert from big-endian order to host byte order.<\/p>\n The functions with names of the form “lenn<\/i>toh” convert from little-endian order to host byte order.<\/p>\n These functions were added to glibc in version 2.9.<\/p>\n These functions are nonstandard. Similar functions are present on the BSDs, where the required header file is These functions are similar to the older byteorder<\/b>(3) family of functions. For example, be32toh<\/b>() is identical to ntohl<\/b>().<\/p>\n The advantage of the byteorder<\/b>(3) functions is that they are standard functions available on all UNIX systems. On the other hand, the fact that they were designed for use in the context of TCP\/IP means that they lack the 64-bit and little-endian variants described in this page.<\/p>\n The program below display the results of converting an integer from host byte order to both little-endian and big-endian byte order. Since host byte order is either little-endian or big-endian, only one of these conversions will have an effect. When we run this program on a little-endian system such as x86-32, we see the following:<\/p>\n $ .\/a.out<\/b> Program source<\/b> int x.arr[0] = 0x11;<\/p>\n \/* Lowest-address byte *\/<\/p>\n<\/td>\n<\/tr>\n<\/table>\n x.arr[1] = 0x22; x.arr[3] = 0x44;<\/p>\n \/* Highest-address byte *\/<\/p>\n<\/td>\n<\/tr>\n<\/table>\n printf(“x.u32 = %#xn”, x.u32); exit(EXIT_SUCCESS);
SYNOPSIS<\/a>
DESCRIPTION<\/a>
VERSIONS<\/a>
CONFORMING TO<\/a>
NOTES<\/a>
EXAMPLES<\/a>
SEE ALSO<\/a>
COLOPHON<\/a> <\/p>\n
\nNAME <\/a> <\/h2>\n
SYNOPSIS <\/a> <\/h2>\n
uint16_t htole16(uint16_t<\/b> host_16bits<\/i>);
uint16_t be16toh(uint16_t<\/b> big_endian_16bits<\/i>);
uint16_t le16toh(uint16_t<\/b> little_endian_16bits<\/i>);<\/b><\/p>\n
uint32_t htole32(uint32_t<\/b> host_32bits<\/i>);
uint32_t be32toh(uint32_t<\/b> big_endian_32bits<\/i>);
uint32_t le32toh(uint32_t<\/b> little_endian_32bits<\/i>);<\/b><\/p>\n
uint64_t htole64(uint64_t<\/b> host_64bits<\/i>);
uint64_t be64toh(uint64_t<\/b> big_endian_64bits<\/i>);
uint64_t le64toh(uint64_t<\/b> little_endian_64bits<\/i>);<\/b><\/p>\n
Since glibc 2.19:
_DEFAULT_SOURCE
In glibc up to and including 2.19:
_BSD_SOURCE<\/p>\nDESCRIPTION <\/a> <\/h2>\n
VERSIONS <\/a> <\/h2>\n
CONFORMING TO <\/a> <\/h2>\n
NOTES <\/a> <\/h2>\n
EXAMPLES <\/a> <\/h2>\n
x.u32 = 0x44332211
htole32(x.u32) = 0x44332211
htobe32(x.u32) = 0x11223344<\/p>\n
#include
#include
#include
#include
main(int argc, char *argv[])
{
union {
uint32_t u32;
uint8_t arr[4];
} x;<\/p>\n\n
\n <\/td>\n <\/td>\n <\/td>\n <\/td>\n \n
x.arr[2] = 0x33;<\/p>\n\n
\n <\/td>\n <\/td>\n <\/td>\n <\/td>\n \n
printf(“htole32(x.u32) = %#xn”, htole32(x.u32));
printf(“htobe32(x.u32) = %#xn”, htobe32(x.u32));<\/p>\n
}<\/p>\nSEE ALSO <\/a> <\/h2>\n