bswap(3)                   Library Functions Manual                   bswap(3)

NAME
       bswap_16, bswap_32, bswap_64 - reverse order of bytes

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <byteswap.h>

       uint16_t bswap_16(uint16_t x);
       uint32_t bswap_32(uint32_t x);
       uint64_t bswap_64(uint64_t x);

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

RETURN VALUE
       These functions return the value of their argument with the bytes
       reversed.

ERRORS
       These functions always succeed.

STANDARDS
       GNU.

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 <byteswap.h>
       #include <inttypes.h>
       #include <stdint.h>
       #include <stdio.h>
       #include <stdlib.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 = strtoull(argv[1], NULL, 0);
           printf("%#" PRIx64 " ==> %#" PRIx64 "\n", x, bswap_64(x));

           exit(EXIT_SUCCESS);
       }

SEE ALSO
       byteorder(3), endian(3)

Linux man-pages 6.7               2023-10-31                          bswap(3)