#!/usr/bin/env bash
  
  # We want to catch any unexpected failure, and exit immediately
  set -e
  
  # Download helper for cvs, to be called from the download wrapper script
  #
  # Call it as:
  #   .../cvs [-q] OUT_FILE CVS_URL REV PKG_NAME BASENAME
  #
  # Environment:
  #   CVS      : the cvs command to call
  
  verbose=
  while getopts :q OPT; do
      case "${OPT}" in
      q)  verbose=-Q;;
      \?) printf "unknown option '%s'
  " "${OPTARG}" >&2; exit 1;;
      esac
  done
  shift $((OPTIND-1))
  
  output="${1}"
  repo="${2}"
  rev="${3}"
  rawname="${4}"
  basename="${5}"
  
  # Caller needs to single-quote its arguments to prevent them from
  # being expanded a second time (in case there are spaces in them)
  _cvs() {
      eval ${CVS} "${@}"
  }
  
  if [[ ${rev} =~ ^[0-9] ]]; then
      # Date, because a tag or a branch cannot begin with a number
      select="-D"
  else
      # Tag or branch
      select="-r"
  fi
  
  # The absence of an initial : on ${repo} means access method undefined
  if [[ ! "${repo}" =~ ^: ]]; then
     # defaults to anonymous pserver
     repo=":pserver:anonymous@${repo}"
  fi
  
  export TZ=UTC
  _cvs ${verbose} -z3 -d"'${repo}'" \
       co -d "'${basename}'" ${select} "'${rev}'" -P "'${rawname}'"
  
  tar czf "${output}" "${basename}"