#!/bin/bash
default_version=$(cat "$(dirname "$0")/../.version")
usage() {
cat <<EOF
Usage: $0 [version(= $default_version) | --help, -h]
Example:
  For a changelog with the following content:
    # A doc
    ## 0.12.1
    text
    ## 0.12.0
    other text
  The command:
    $ $0 0.12.1
  Would display:
    text
EOF
}
version=${1:-$default_version}
[ "$1" = "--help" -o "$1" = "-h" ] && { usage ; exit 0; }
changelog="$(dirname "$0")/../changelog.md"
awk \
  -v section="## $version" \
  '
  $0 ~ section { in_section=1; next }
  in_section && /^## / && $0 != section { in_section=0 }
  in_section { print }' \
  "$changelog"