sepastian

https://en.wikipedia.org/wiki/Magic_SysRq_key

sepastian

# Prerequisites:
# - gdal2tiles.py (https://gdal.org/)
# - map.tit, a GeoTIFF file generated, for example, by QGIS

$ sudo apt install gdal-bin
$ gdal2tiles.py map.tif tiles
$ cd tiles && python -m http.server

# Go to http://localhost:8000/leaflet.html;
# place tiles/ on a web server and create a L.tileLayer using the tiles.

sepastian

// Extract is a nested document, which exists in some documents only.
//
// Collection data defines a partial index on extract.created_at.
//
// Finding documents which have extract set takes long, if the collection is large.
//
// Use hint() to search the index extarct.created_at in determining, if extract exists.
db.data.getIndices()
/*
{

sepastian

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'
# From https://unix.stackexchange.com/a/18631/56290
# Rotate even pages by 180 degrees, don't rotate odd pages.
pdftk A=infile.pdf shuffle Aoddnorth Aevensouth output outfile.pdf

sepastian

# Touch a file containing self-signed certificates to be used by git.
touch ~/.git-certs
chmod 600 ~/.git-certs

# Append the certificate to the file created aboe. 
# https://stackoverflow.com/questions/7885785/using-openssl-to-get-the-certificate-from-a-server#comment26410932_7886248
echo \
  | openssl s_client -connect my.server.com:443 2>&1 \
  | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' \
  >> ~/.git-certs

sepastian

# Match .msg against case-insensitive regex;
# output .name and .time of matching documents.
jq 'select(.msg|test("aggregating variable";"i")) | .name,.time' input.json

# Output single line, as CSV.
jq -c 'select(.msg|test("aggregating variable";"i")) | .name,.time' input.json | tr -d '[]'

# Output value, default to 0, if field is missing.
jq '.value // 0' input.json

sepastian

# https://stackoverflow.com/questions/49839028/how-to-upgrade-docker-compose-to-latest-version

sudo apt remove docker-compose
VERSION=$(curl --silent https://api.github.com/repos/docker/compose/releases/latest | jq .name -r)
DESTINATION=/usr/local/bin/docker-compose
sudo curl -L https://github.com/docker/compose/releases/download/${VERSION}/docker-compose-$(uname -s)-$(uname -m) -o $DESTINATION
sudo chmod +x $DESTINATION

sepastian

# Assuming there's a Docker container runninng Mongo, named `mongo1`,
# fire up another container `mongo2`,
# mounting a directory containing data to import,
# and execute `mongoimport` inside `mongo2`,
# to import data into `mongo1`.

# Start `mongo2`:
# link it to the running `mongo1`;
# open a bash session;
# mount pwd to /import;

sepastian

ls | rev | cut -d '.' -f 1 | rev | sort | uniq -c

sepastian

Purpose

Avoid typing username/password for every push.

See https://git-scm.com/docs/git-credential-store#_examples

$ git config credential.helper store
$ git push http://example.com/repo.git
Username: