ccan

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Module:

endian

Summary:

endian conversion macros for simple types

Author:

Rusty Russell <rusty@rustcorp.com.au>

Description:

Portable protocols (such as on-disk formats, or network protocols) are often defined to be a particular endian: little-endian (least significant bytes first) or big-endian (most significant bytes first).

Similarly, some CPUs lay out values in memory in little-endian order (most commonly, Intel's 8086 and derivatives), or big-endian order (almost everyone else).

This module provides conversion routines, inspired by the linux kernel. It also provides leint32_t, beint32_t etc typedefs, which are annotated for the sparse checker.

Example:

#include <stdio.h>
#include <err.h>
#include <ccan/endian/endian.h>

// 
int main(int argc, char *argv[])
{
        uint32_t value;

        if (argc != 2)
                errx(1, "Usage: %s <value>", argv[0]);

        value = atoi(argv[1]);
        printf("native:        %08x\n", value);
        printf("little-endian: %08x\n", cpu_to_le32(value));
        printf("big-endian:    %08x\n", cpu_to_be32(value));
        printf("byte-reversed: %08x\n", bswap_32(value));
        exit(0);
}

License: