bswap_64(3)

BSWAP(3)                   Linux Programmer's Manual                  BSWAP(3)

NAME
       bswap_16, bswap_32, bswap_64 - reverse order of bytes

SYNOPSIS
       #include <byteswap.h>

       bswap_16(x);
       bswap_32(x);
       bswap_64(x);

DESCRIPTION
       These  macros  return  a value in which the order of the bytes in their
       2-, 4-, or 8-byte arguments is reversed.

RETURN VALUE
       These macros return the value of their  argument  with  the  bytes  re-
       versed.

ERRORS
       These macros always succeed.

CONFORMING TO
       These macros are GNU extensions.

EXAMPLES
       The program below swaps the bytes of the 8-byte integer supplied as its
       command-line argument.  The following shell  session  demonstrates  the
       use of the program:

           $ ./a.out 0x0123456789abcdef
           0x123456789abcdef ==> 0xefcdab8967452301

   Program source

       #include <stdio.h>
       #include <stdint.h>
       #include <stdlib.h>
       #include <inttypes.h>
       #include <byteswap.h>

       int
       main(int argc, char *argv[])
       {
           uint64_t x;

           if (argc != 2) {
               fprintf(stderr, "Usage: %s <num>\n", argv[0]);
               exit(EXIT_FAILURE);
           }

           x = strtoul(argv[1], NULL, 0);
           printf("0x%" PRIx64 " ==> 0x%" PRIx64 "\n", x, bswap_64(x));

           exit(EXIT_SUCCESS);
       }

SEE ALSO
       byteorder(3), endian(3)

COLOPHON
       This  page  is  part of release 5.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.

Linux                             2020-06-09                          BSWAP(3)