php man page for bswap

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 reversed.

ERRORS
       These macros always succeed.

CONFORMING TO
       These macros are GNU extensions.

EXAMPLE
       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>
", argv[0]);
	       exit(EXIT_FAILURE);
	   }

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

	   exit(EXIT_SUCCESS);
       }

SEE ALSO
       byteorder(3), endian(3)

COLOPHON
       This page is part of release 4.15 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								    2017-09-15								  BSWAP(3)