tbytes 0.1.0

#!/usr/bin/env bash
#
# CLI processing inspired by François Saint-Jacques's `semver-tool`:
#   https://github.com/fsaintjacques/semver-tool
#

set -o errexit -o nounset -o pipefail

PROG=pkg-version
PROG_VERSION="0.1.0"

USAGE="\
Usage:
  $PROG --package <package>
  $PROG --all
  $PROG --help
  $PROG --version

Arguments:
  <package>  Cargo package name.

Options:
  -p, --package          Print version for specific package.
  -a, --all              Print versions for all packages within a workspace.
  -v, --version          Print the version of this tool.
  -h, --help             Print this help message.
"

function error {
  echo -e "$1" >&2
  exit 1
}

function usage_help {
  error "$USAGE"
}

function usage_version {
  echo -e "${PROG}: $PROG_VERSION"
  exit 0
}

function is_empty {
  [ $# -eq 0 ]
}

function specific_package {
  is_empty "$@" && { error "ERROR! Package name should be specified.\n\n$USAGE"; }
  local package=$1;

  cargo metadata --no-deps --format-version 1 | \
        jq '.packages[] | select(.name == "'"$package"'") | .version' | \
        tr -d '"'
  exit 0
}

function all_packages {
  cargo metadata --no-deps --format-version 1 | \
        jq '.packages[] | [.name, .version] | join(" ")' | \
        tr -d '"'
  exit 0
}

case $# in
  0) echo "Unknown command: $*"; usage_help;;
esac

case $1 in
  --help|-h) echo -e "$USAGE"; exit 0;;
  --version|-v) usage_version ;;
  --package|-p) shift; specific_package "$@";;
  --all|-a) all_packages ;;
  *) echo "Unknown arguments: $*"; usage_help;;
esac