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#!/usr/bin/env python3

# SPDX-FileCopyrightText: © 2022 Georg Sauthoff <mail@gms.tf>
# SPDX-License-Identifier: BSL-1.0

import argparse
import http.server
import json
import sys

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/* Demonstrate how to remove an environment variable from /proc/$pid/environ,
   under Linux.
   This pseudo file is accessible by other processes with sufficient privileges
   (i.e. same user or root) and exposes the original environment vector.
   Removing sensitive variables from it can be part of a defense in depth
   strategy (i.e. to make it harder for a casual attacker to access it).
 */

/** {{{ MIT No Attribution

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import operator
import re

split_version_re = re.compile('[.+-]')

class LooseVersion:
    def __init__(self, s):
        self.vs = split_version_re.split(s)
        self.n  = max(len(x) for x in self.vs)
    def cmp(self, other, op):

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// 2022, Georg Sauthoff <mail@gms.tf>

void setup() {
    Serial.begin(9600);
    Serial.println("Ready.");

    cli(); // atomic section

    // set Arduino Pin 3 low
    PORTD &= ~ _BV(PORTD3);

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Dec 20 21:24:24 sos.lru.li kernel: ata3.00: exception Emask 0x10 SAct 0xffffffff SErr 0x440100 action 0x6 frozen
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: irq_stat 0x08000000, interface fatal error
Dec 20 21:24:24 sos.lru.li kernel: ata3: SError: { UnrecovData CommWake Handshk }
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: failed command: READ FPDMA QUEUED
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: cmd 60/00:00:00:50:42/01:00:13:00:00/40 tag 0 ncq dma 131072 in
                                            res 40/00:08:00:51:cf/00:00:0f:00:00/40 Emask 0x10 (ATA bus error)
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: status: { DRDY }
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: failed command: WRITE FPDMA QUEUED
Dec 20 21:24:24 sos.lru.li kernel: ata3.00: cmd 61/00:08:00:51:cf/01:00:0f:00:00/40 tag 1 ncq dma 131072 out
                                            res 40/00:08:00:51:cf/00:00:0f:00:00/40 Emask 0x10 (ATA bus error)

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smartctl 7.1 2019-12-30 r5022 [x86_64-linux-5.8.18-300.fc33.x86_64] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Samsung based SSDs
Device Model:     Samsung SSD 860 EVO 250GB
Serial Number:    [..]
LU WWN Device Id: [..]
Firmware Version: RVT04B6Q
User Capacity:    250,059,350,016 bytes [250 GB]

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// source: http://unix.stackexchange.com/a/163115/1131
// GS, 2016-01-27, simplify the code a little bit

#include <QApplication>
#include <QTimer>
#include <QClipboard>
#include <QMimeData>
#include <QDebug>
#include <string>
#include <iostream>

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# I218-V rev 4, e1000e, Core i5 Haswell, CentOS 7

ptp-clock-offset /dev/ptp0
## Testing PTP_SYS_OFFSET ioct (1128283397)
PTP_SYS_OFFSET no 1: -710924824 ns, delay: 6734 ns
PTP_SYS_OFFSET no 2: -710922059 ns, delay: 3873 ns
PTP_SYS_OFFSET no 3: -710922092 ns, delay: 3889 ns
PTP_SYS_OFFSET no 4: -710922078 ns, delay: 3888 ns
PTP_SYS_OFFSET no 5: -710922096 ns, delay: 3939 ns
## Testing PTP_SYS_OFFSET_EXTENDED ioctl (3300932873)

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# assuming /mnt/root/{root,home} are mounts of anothers system root+home filesystems

cd /mnt/root/root
mount --bind /proc proc
mount --bind /sys sys
mount --bind /dev dev
cp /etc/resolv.conf etc/
cd /mnt/root
mount --bind home root/home
chroot root /usr/bin/zsh

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/* For illustrating how orphaned children aren't necessarily adopted
   by PID 1.

   See also: http://stackoverflow.com/questions/284325/how-to-make-child-process-die-after-parent-exits/36945270#36945270

   2016, Georg Sauthoff <mail@georg.so>
*/


#include <unistd.h>