Template for new bash scripts without getopts

bash_template.sh

#!/usr/bin/env bash
# The following variables are used to describe this script in detail
description="$(basename $0): DESCRIPTION"
version="0.0.1-dev"
author="AUTHOR"
usage_info="
Usage: $(basename $0) ARGS

Arguments: 
    ...

Environment variables: 
    ...

Version: $version
"
############ Development notes ...
# ...

############################################################################### 

################################ Describe the environment

# Base directory of this script 
basedir="$(dirname "$(readlink -f "$BASH_SOURCE")")"

# .... space for other variables ... 


################################ Helper Functions 

######## execv
## Print the executed command
## Usage: execv <command line>
## Note: 
##   Quotations are not printed. Therefore, 
##   the printed command is not completely safe to be re-executed. 
##   Set _execv_disabled=true to disable the verbose output
#
function execv
{
    prompt="## "
    [ "$_execv_disabled" = true ] || echo "${prompt}$@"
    "$@"
}

######## raise_error
## Print error message and exit with status code 1
## Usage: raise_error <error message>
#
function raise_error
{
    prompt=""
    echo "${prompt}$@" 1>&2
    exit 1
}

######## show_usage
## Print the usage information 
## Usage: show_usage [error message]
## Note: 
##   If the error message is passed, then the message 
##   is printed to stderr and the program terminates with 1. 
#    
function show_usage 
{
    error_msg="$1"
    if [ -z "$error_msg" ]
    then 
        echo "$description"
        echo "$usage_info" 
        exit 0
    else 
        echo "Error: $error_msg" 1>&2
        echo "$usage_info" 1>&2
        exit 1
    fi
}

######## .... space for other functions ... 

######## FUNCTION_NAME
## INFO_MESSAGE
## Usage: 
#
function print_the_answer
{
    the_question="$1"
    : ${the_question:?"is empty"}
    echo "42"
}

################################ MAIN

#### Without any arguments: 
# show the usage information and exit with status code 0 [success]
[ $# -eq 0 ] && show_usage 


#### Validate $1: the question
the_question="$1" 
[ -n "$the_question"  ] || show_usage "The question is missing"
[ $# -eq 1            ] || show_usage "The question has to be passed as a single argument."

# ... space for more validation ...


################ do the stuff
print_the_answer $the_question