[bash 4+] fill .gitignore with popular templates (from GitHub)

gitignore.sh

#!/bin/bash

function is_present () {
  command -v "$1" &>/dev/null
}

if ! is_present curl; then
  echo "curl not found"
  exit 1
fi

function ignore () {
  if ! curl --fail -H "Accept: application/vnd.github.raw" \
  "https://api.github.com/gitignore/templates/${1^}" 2>/dev/null; then
    (>&2 echo "not found")
  fi
}

if test $# -gt 0; then
  ignore $1 >> .gitignore
fi