serialnumber_sysfs.c

//-------------------------------------------------------------------------
//
// The MIT License (MIT)
//
// Copyright (c) 2020 Andrew Duncan
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//-------------------------------------------------------------------------

#include <ctype.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//-----------------------------------------------------------------------

int main(void)
{
    uint32_t serial = 0;

    FILE *fp = fopen("/sys/firmware/devicetree/base/serial-number", "r");

    if (fp == NULL)
    {
        perror("/sys/firmware/devicetree/base/serial-number");
        exit(EXIT_FAILURE);
    }

    char value[80];

    if (fgets(value, sizeof(value), fp) != NULL)
    {
        serial = strtoul(value, NULL, 16);
    }

    fclose(fp);

    printf("serial: %016"PRIx32"\n", serial);

    return 0;
}