mount_drive

#!/bin/bash

## Bash settings
set -uo pipefail

## Script globals
script_name=$(basename "${BASH_SOURCE[0]}")
script_dir=$({ cd "$(dirname "${BASH_SOURCE[0]}")" || { echo "Failed to access script file directory" >&2; exit; } } && pwd)
script_dir_abs=$({ cd "$(dirname "${BASH_SOURCE[0]}")" || { echo "Failed to access script file directory" >&2; exit; } } && pwd -P)
script_file="${script_dir}/${script_name}"
if [ -L "${BASH_SOURCE[0]}" ]; then
    script_file_abs=$(readlink "${BASH_SOURCE[0]}")
else
    script_file_abs="${script_dir_abs}/${script_name}"
fi
export CURRENT_PARENT_BASH_SCRIPT_FILE="$script_file"
script_args=("$@")

## Script imports
lib_dir="${script_dir}/../lib"
bash_functions_script="${lib_dir}/bash_script_func.sh"

## Source imports
source "$bash_functions_script"


## Arguments
drive_arr=()
dryrun=false

## Custom globals
re_drive_letter='[a-zA-Z]'


## Script usage
read -r -d '' script_usage << EOM
Usage: ${script_name} DRIVE_LETTER...

Permanently mount Windows network/removable drive(s) by making
additions to the /etc/fstab file. Primarily useful for setup of
the Windows Subsystem for Linux Bash terminal.

Options:
-db,--debug
-dr,--dryrun
        Print commands used to mount drive(s), without executing.
EOM
if (( $# < 1 )); then
    echo_e "$script_usage"
    exit_script_with_status 1
fi


## Parse arguments
set +u
while (( $# > 0 )); do
    arg="$1"

    if [ "$(string_startswith "$arg" '-')" = false ]; then
        if [ "$(re_test "$re_drive_letter" "$arg")" = true ]; then
            drive_arr+=( "$arg" )
        else
            echo_e "Unexpected argument: ${arg}"
            exit_script_with_status 1
        fi

    else
        arg_opt="$(string_lstrip "$arg" '-')"
        arg_opt_nargs=''
        if [ "$(string_contains "$arg_opt" '=')" = true ]; then
            arg_val=$(printf '%s' "${arg_opt#*=}" | sed -r -e "s|^['\"]+||" -e "s|['\"]+$||")
            arg_opt="${arg_opt%%=*}"
            arg_opt_nargs_do_shift=false
        else
            arg_val="$2"
            arg_opt_nargs_do_shift=true
        fi
        arg_val_can_start_with_dash=false

        if [ "$arg_opt" = 'h' ] || [ "$arg_opt" = 'help' ]; then
            arg_opt_nargs=0
            echo "$script_usage"
            exit 0

        elif [ "$arg_opt" = 'db' ] || [ "$arg_opt" = 'debug' ]; then
            arg_opt_nargs=0
            dryrun=true

        elif [ "$arg_opt" = 'dr' ] || [ "$arg_opt" = 'dryrun' ]; then
            arg_opt_nargs=0
            dryrun=true

        else
            echo_e "Unexpected argument: ${arg}"
            exit_script_with_status 1
        fi

        if [ -z "$arg_opt_nargs" ]; then
            echo_e "Developer error! "'$arg_opt_nargs'" was not set for argument: ${arg}"
            exit_script_with_status 1
        fi

        if [ "$arg_opt_nargs_do_shift" = true ] && (( arg_opt_nargs >= 1 )); then
            for arg_num in $(seq 1 $arg_opt_nargs); do
                shift
                arg_val="$1"
                if [ -z "$arg_val" ]; then
                    echo_e "Missing expected value (#${arg_num}) for argument: ${arg}"
                    exit_script_with_status 1
                elif [ "$arg_val_can_start_with_dash" = false ] && [ "$(string_startswith "$arg_val" '-')" = true ]; then
                    echo_e "Unexpected argument value: ${arg} ${arg_val}"
                    exit_script_with_status 1
                fi
            done
        fi
    fi

    shift
done
set -u


## Validate arguments

if (( ${#drive_arr[@]} == 0 )); then
    echo_e "At least one drive letter argument must be provided"
    exit_script_with_status 1
fi


## Mount drives

for drive in "${drive_arr[@]}"; do
    drive_lower=$(string_to_lowercase "$drive")
    drive_upper=$(string_to_uppercase "$drive")
    echo -e "\nConfiguring ${drive_upper} drive"

    drive_path="/mnt/${drive_lower}"

    if [ -d "$drive_path" ]; then
        cmd="sudo chmod 777 ${drive_path}"
    else
        cmd="sudo mkdir -m 777 ${drive_path}"
    fi
    echo -e "-> Initializing drive path with command:\n    ${cmd}"
    if [ "$dryrun" = false ]; then
        eval "$cmd"
    fi

    fstab_drive_line="${drive_upper}: /mnt/${drive_lower} drvfs defaults 0 0"
    fstab_line_exists=$(grep "$fstab_drive_line" "/etc/fstab")
    if [ -n "$fstab_line_exists" ]; then
        echo -e "-> Drive setting already exists in /etc/fstab:\n    ${fstab_drive_line}"
    else
        cmd="sudo bash -c 'echo ${fstab_drive_line} >> /etc/fstab'"
        echo -e "-> Adding drive setting to /etc/fstab with command:\n    ${cmd}"
        if [ "$dryrun" = false ]; then
            eval "$cmd"
        fi
    fi
done
echo

cmd="sudo mount -a"
echo -e "Mounting all drives with command:\n    ${cmd}"
if [ "$dryrun" = false ]; then
    eval "$cmd"
    echo -e "\nDone!"
fi