Simple continous build script for XeLaTeX document

build.sh

#!/bin/bash

declare -r MAIN=main
declare -r SOURCES=main.tex
declare -r OUTPUT_DIR=build

# Options
declare CONTINUOUS

function launch() {
    declare -r COMMAND="${@}"
    if [[ -n "${CONTINUOUS}" ]]; then
        echo "Building continously..."
        declare ITERATION=1
        ${COMMAND}
        while inotifywait ${SOURCES}; do
            echo -e "${ITERATION}\t Building..."
            ${COMMAND}
            ITERATION="$((${ITERATION} + 1))"
        done
    else
        ${COMMAND}
    fi
}

function usage() {
    echo "$0 [OPTIONS...]"
    echo ""
    echo "    OPTIONS:"
    echo "        -c: Enable continuous build (build on file change)"
}

while getopts "ch" OPTION; do
    case $OPTION in
        c)
            CONTINUOUS="true"
            ;;
        h)
            usage
            exit 0
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            exit 1
            ;;
    esac
done

mkdir -p "${OUTPUT_DIR}"
launch xelatex -halt-on-error -output-directory="${OUTPUT_DIR}" "${MAIN}"