Bash coproc and SQLite

#! /bin/bash
# Testing 'coproc' feature in Bash with SQLite

SQL_DB=${1:-test.db}

coproc sqlproc {
    # non-existig file "none" ignores reading ~/.sqliterc
    sqlite3 -init none
}

SQL_IN=${sqlproc[0]}
SQL_OUT=${sqlproc[1]}


Sql ()
{
    local stmt=$1

    if [[ $stmt =~ ^\. ]]; then
        : # Skip, SQLite internal ".command"
    elif [[ ! $stmt =~ \;[[:space:]]*$ ]]; then
        # Add missing semicolong
        stmt+=";"
    fi

    printf '%s\n' "$stmt" '.shell printf \\0' >&"$SQL_OUT"
    IFS= read -r -d '' -u "$SQL_IN"  # output in $REPLY
}


SqlClose ()
{
    Sql ".quit"
    wait
}

Main ()
{
    Sql ".open $SQL_DB"
    echo "$REPLY"

    Sql ".tables"
    echo "$REPLY"

    Sql "SELECT * FROM emp;"
    echo "$REPLY"
}


# Close coproc on exit
trap SqlClose EXIT

Main "$@"

# End of file