jigpu

General Tips & Tricks

Using coredumpctl

Most Linux systems use systemd for their init system, and systemd includes a component that automatically saves coredumps for crashed processes. The coredumpctl command can be used to discover crashing processes, obtain backtraces, export coredumps, or launch GDB. Combined with debug symbols it is easy to get information about a crash from users who may not be especially technical.

1. Replicate the crash

2. Run coredumpctl list --since "5 minutes ago" to see all crashes logged in the last 5 minutes

3. Run coredumpctl info to get a basic backtrace of a particular crashed PID or EXE

jigpu

#!/bin/bash
rsleep () { sleep $(awk -vM=$1 -vN=4 'BEGIN{"od -N"N" -tu"N" -A none /dev/urandom"|getline;print M*$0/(2^(8*N)-1)}'); }

WAIT=2

while :; do
        rsleep $WAIT
        echo -n .
        rmmod wacom
        echo -n v

jigpu

# NOTE: When run in an environment which uses 'mawk' (e.g. Ubuntu), it is
# recommended to set the environment variable WHINY_USERS to ensur the
# output is sorted: `sudo evemu-record | WHINY_USERS=1 awk -f evemu-live.awk`

BEGIN {
	SUBSEP="\t";
	PROCINFO["sorted_in"]="@ind_str_asc";
	"tput clear" | getline Clear;
	"tput cup 0 0" | getline Home;

jigpu

#!/bin/sh

# Start sampling data from a Uni-T UT61E connected over the serial port
# See https://sigrok.org/gitweb/?p=libsigrok.git;a=blob;f=README.devices
#
# For a USB connection, the "-ser" suffix should be removed from the driver
# and the "conn" updated to use the VID:PID of the cable being used (note
# that it isn't simply a serial-to-USB cable)

sigrok-cli --driver=uni-t-ut61e-ser:conn=/dev/ttyS0 --continuous

jigpu

python3 -c 'open(1,"wb").write(bytearray.fromhex(" ".join(open(0).read().split())))'

jigpu

#!/usr/bin/python3

"""Control brightness and contrast of a monitor exposing DDC over an FTDI F232H.

Usage:
    ddc-ftdi.py [<brightness> <contrast>]

Arguments:
    <brightness>   Brightness value to set (0..100)
    <contrast>     Contrast value to set (0..100)

jigpu

#!/bin/sh

# Note:
# https://en.wikipedia.org/wiki/ANSI_escape_code
# https://www.fileformat.info/info/unicode/block/block_elements/list.htm

function spin {
	CHRS=$1
	DELAY=$2
	X=0;

jigpu

#!/usr/bin/env bash

# Script to handle automatic snapshotting and restoring of test machines.
# This script should be run early in the startup process to see if the
# user wants to continue/create a session or to delete an existing
# session and start over fresh.

set -e
[ $EUID == 0 ] || exec sudo "$0" "$@"

jigpu

diff --git a/4.5/Makefile.in b/4.5/Makefile.in
index 438229b..dd89344 100644
--- a/4.5/Makefile.in
+++ b/4.5/Makefile.in
@@ -22,6 +22,9 @@ DRACUT := $(shell command -v dracut 2>/dev/null)
 WCM_KERNEL_DIR := @WCM_KERNEL_DIR@
 MODUTS := @MODUTS@
 WCM_KERNEL_VER := @WCM_KERNEL_VER@
+MODSIGN_HASHALGO := @MODSIGN_HASHALGO@
+MODSIGN_PRIVFILE := @MODSIGN_PRIVFILE@

jigpu

#!/bin/bash

#
# Map all display tablets to the correct monitor.
#
# This script tries to atuomatically determine the correct monitor to
# map every connected tablet to. It uses the tablet size to find a
# best match among the available Wacom-branded monitors. If no match
# is found, then we assume that either the monitor isn't connected or
# the tablet doesn't have a display.