Overengineered and overly-portable script for doing stuff in a temporary pgsql database

tmp_pg.sh

#!/bin/sh -e
# Adapted from the Hashbang userdb testing script:
#  https://github.com/hashbang/userdb/blob/master/test.sh


run() {
    normal='\e[0m'
    yellow='\e[33m'
    printf "${yellow}%s${normal}\n" "$*" >&2

    "$@"
}

# Some distros support multiple installed versions of PostgreSQL
if ! command -v initdb 2>/dev/null; then
    for dir in /usr/lib/postgresql/*; do
	      export PATH="${dir}/bin:${PATH}"
    done
fi

if ! command -v initdb 2>/dev/null; then
    echo "No PostgreSQL utilities in PATH" >&2
    exit 1
fi

trap 'pg_ctl -D "${WORKDIR}" stop; rm -rf -- "${WORKDIR}"' EXIT
WORKDIR=$(mktemp -d)

run initdb -D "${WORKDIR}"
run pg_ctl -D "${WORKDIR}" start -w -o "      \
	-c unix_socket_directories=${WORKDIR} \
	-c listen_addresses=''                \
"

# Set the environment to use the temporary pgsql by default
export PGHOST="${WORKDIR}"
export PGDATABASE="postgres"

# Do your things here
## Either run a user-provided command...
if [ $# -gt 0 ]; then
    "$@"

## ...or a fancy Postgres terminal UI...
elif command -v pgcli 2>/dev/null; then
    pgcli

## ...or a not-fancy one.
else
    psql
fi