Compiles a binary in a temporary sandbox and moves the binaries to \$HOME/.cabal/bin or to the path set by SANDBOX_INSTALL_DIR.

cabal-sandbox-install

#!/usr/bin/env bash

# Utility functions

## Logging
log_debug()   {
  if [ "$OPT_VERBOSE" = true ]; then
    echo "$(tput setaf 5)Debug:  $(tput sgr 0)" "$@"
  fi
}

log_info()    { echo "$(tput setaf 6)Info:   $(tput sgr 0)" "$@"; }
log_warning() { echo "$(tput setaf 3)Warning:$(tput sgr 0)" "$@"; }
log_success() { echo "$(tput setaf 2)Success:$(tput sgr 0)" "$@"; }
log_error()   { echo "$(tput setaf 1)Error:  $(tput sgr 0)" "$@" 1>&2; }

## Assertions
check_path() {
  if [[ ! ":$PATH:" == *":$1:"* ]]; then
    log_warning "'$1' is not in your PATH"
    log_warning "You should add '$1' to your PATH and restart your terminal"
  fi
}

check_installed() {
  command -v "$1" >/dev/null
  return $?
}

assert_installed() {
  log_debug "Checking for '$1'"
  check_installed "$1"
  if [ $? -ne 0 ]; then
    log_error "$1" "not installed."
    exit 1
  fi
}

update_cabal() {
  log_info "Updating Cabal's list of packages"

  cabal update
  if [ $? -ne 0 ]; then
    log_error "Failed updating Cabal's list of packages"
    exit 1
  fi
}

warn_if_exists() {
  if [ -f "$1" ] && [ "$OPT_FORCE" = false ]; then
    log_warning "$1 already exists. This may cause the copying binaries to fail. Use --force to overwrite."
  fi
}

assert_home() {
  if [ -z "$HOME" ]; then
    log_error "HOME environment variable is not set."
    exit 4
  fi
}

## Trap management

### Appends `trap` calls instead of overwriting
trap_add() {
  # By Richard Hansen, from http://stackoverflow.com/a/7287873
  trap_add_cmd=$1; shift || fatal "${FUNCNAME} usage error"
  for trap_add_name in "$@"; do
    trap -- "$(
        # helper fn to get existing trap command from output
        # of trap -p
        extract_trap_cmd() { printf '%s\n' "$3"; }
        # print existing trap command with newline
        eval "extract_trap_cmd $(trap -p "${trap_add_name}")"
        # print the new trap command
        printf '%s\n' "${trap_add_cmd}"
    )" "${trap_add_name}" \
        || fatal "unable to add to trap ${trap_add_name}"
  done
}

declare -f -t trap_add

## Temporary directory that automatically cleans up
make_temp_dir() {
  TEMP_DIR=$(mktemp -d 2>/dev/null || mktemp -d -t 'mytmpdir')
  trap_add "log_debug Removing temporary directory \'$TEMP_DIR\'; rm -rf $TEMP_DIR" EXIT

  log_debug "Using temporary directory '$TEMP_DIR'"
}

## Change to directory and return on script exit
run_from() {
  trap_add 'popd &>/dev/null' EXIT
  pushd . &>/dev/null
  cd "$1"
}

# sandbox-install
get_install_dir() {
  if [ -z "$SANDBOX_INSTALL_DIR" ]; then
    log_debug "SANDBOX_INSTALL_DIR not set. Using default install location."
    assert_home
  fi

  SANDBOX_INSTALL_DIR=${SANDBOX_INSTALL_DIR:-$HOME/.cabal/bin}

  log_info "Installing to '${SANDBOX_INSTALL_DIR}'"
}

init_sandbox() {
  log_info "Initializing Cabal sandbox"
  cabal sandbox init

  if [ $? -ne 0 ]; then
    log_error "Failed to initialize sandbox"
    exit 1
  fi
}

install() {
  log_info "Installing '$1'"
  cabal install "$1"

  if [ $? -ne 0 ]; then
    log_error "Failed to install '$1' into sandbox"
    exit 1
  fi
}

create_install_dir() {
  if [ ! -d "$SANDBOX_INSTALL_DIR" ]; then
    log_warning "Installation directory '${SANDBOX_INSTALL_DIR}'' does not exist"
    log_info "Creating '${SANDBOX_INSTALL_DIR}'"

    mkdir -p "$SANDBOX_INSTALL_DIR"
    if [ $? -ne 0 ]; then
      log_error "Failed to create '$SANDBOX_INSTALL_DIR'"
      exit 1
    fi
  fi
}

copy_binaries() {
  log_info "Copying binaries from '$TEMP_DIR/.cabal-sandbox/bin'"
  log_info "                 to   '$SANDBOX_INSTALL_DIR'"

  for f in $TEMP_DIR/.cabal-sandbox/bin/*
  do
    log_info "Copying '${f##*/}'"

    if [ "$OPT_FORCE" = true ]; then
      cp "$f" "$SANDBOX_INSTALL_DIR/"
    else
      cp -n "$f" "$SANDBOX_INSTALL_DIR/"
    fi

    if [ $? -ne 0 ]; then
      log_error "Failed to copy '${f##*/}'"
      exit 1
    fi
  done
}

usage() {
  cat << EOF

Compiles a binary in a temporary sandbox and moves the binaries to
\$HOME/.cabal/bin or to the path set by SANDBOX_INSTALL_DIR.

Usage: $(basename "$0") [options] [package-name]

  -f, --force    Overwrites existing files on install
  -h, --help     Print this message
  -v, --verbose  Turn on verbose output

Current install location: $SANDBOX_INSTALL_DIR

EOF

  exit 0;
}

get_install_dir

# Parse options
OPT_FORCE=false

OPT_SPEC=":fhv-:"
while getopts "$OPT_SPEC" optchar; do
  case "${optchar}" in
    -) case "${OPTARG}" in
         force)   OPT_FORCE=true;;
         help)    usage;;
         verbose) OPT_VERBOSE=true;;
       esac;;
    f) OPT_FORCE=true;;
    h) usage;;
    v) OPT_VERBOSE=true;;
  esac
done

shift $(expr $OPTIND - 1 )

# Default run options
if [ -z "$1" ]; then usage; fi

log_info "Attempting to install" \'"$1"\'
create_install_dir
warn_if_exists "$SANDBOX_INSTALL_DIR/$1"
make_temp_dir
assert_installed cabal
run_from "$TEMP_DIR"
init_sandbox
update_cabal
install "$1"
copy_binaries
log_success "Installed '$1'"
check_path "$SANDBOX_INSTALL_DIR"