(function(Prism) {
    var insideString = {
        variable: [
            // Arithmetic Environment
            {
                pattern: /\$?\(\([\s\S]+?\)\)/,
                inside: {
                    // If there is a $ sign at the beginning highlight $(( and )) as variable
                    variable: [{
                        pattern: /(^\$\(\([\s\S]+)\)\)/,
                        lookbehind: true
                    },
                        /^\$\(\(/,
                    ],
                    number: /\b-?(?:0x[\dA-Fa-f]+|\d*\.?\d+(?:[Ee]-?\d+)?)\b/,
                    // Operators according to https://www.gnu.org/software/bash/manual/bashref.html#Shell-Arithmetic
                    operator: /--?|-=|\+\+?|\+=|!=?|~|\*\*?|\*=|\/=?|%=?|<<=?|>>=?|<=?|>=?|==?|&&?|&=|\^=?|\|\|?|\|=|\?|:/,
                    // If there is no $ sign at the beginning highlight (( and )) as punctuation
                    punctuation: /\(\(?|\)\)?|,|;/
                }
            },
            // Command Substitution
            {
                pattern: /\$\([^)]+\)|`[^`]+`/,
                inside: {
                    variable: /^\$\(|^`|\)$|`$/
                }
            },
            /\$(?:[a-z0-9_#\?\*!@]+|\{[^}]+\})/i
        ],
    };

    Prism.languages.bash = {
        'shebang': {
            pattern: /^#!\s*\/bin\/bash|^#!\s*\/bin\/sh/,
            alias: 'important'
        },
        'comment': {
            pattern: /(^|[^"{\\])#.*/,
            lookbehind: true
        },
        'string': [
            //Support for Here-Documents https://en.wikipedia.org/wiki/Here_document
            {
                pattern: /((?:^|[^<])<<\s*)(?:"|')?(\w+?)(?:"|')?\s*\r?\n(?:[\s\S])*?\r?\n\2/g,
                lookbehind: true,
                greedy: true,
                inside: insideString
            },
            {
                pattern: /(["'])(?:\\\\|\\?[^\\])*?\1/g,
                greedy: true,
                inside: insideString
            }
        ],
        'variable': insideString.variable,
        // Originally based on http://ss64.com/bash/
        'function': {
            pattern: /(^|\s|;|\||&)(?:alias|apropos|apt-get|aptitude|aspell|awk|basename|bash|bc|bg|builtin|bzip2|cal|cat|cd|cfdisk|chgrp|chmod|chown|chroot|chkconfig|cksum|clear|cmp|comm|command|cp|cron|crontab|csplit|cut|date|dc|dd|ddrescue|df|diff|diff3|dig|dir|dircolors|dirname|dirs|dmesg|du|egrep|eject|enable|env|ethtool|eval|exec|expand|expect|export|expr|fdformat|fdisk|fg|fgrep|file|find|fmt|fold|format|free|fsck|ftp|fuser|gawk|getopts|git|grep|groupadd|groupdel|groupmod|groups|gzip|hash|head|help|hg|history|hostname|htop|iconv|id|ifconfig|ifdown|ifup|import|install|jobs|join|kill|killall|less|link|ln|locate|logname|logout|look|lpc|lpr|lprint|lprintd|lprintq|lprm|ls|lsof|make|man|mkdir|mkfifo|mkisofs|mknod|more|most|mount|mtools|mtr|mv|mmv|nano|netstat|nice|nl|nohup|notify-send|npm|nslookup|open|op|passwd|paste|pathchk|ping|pkill|popd|pr|printcap|printenv|printf|ps|pushd|pv|pwd|quota|quotacheck|quotactl|ram|rar|rcp|read|readarray|readonly|reboot|rename|renice|remsync|rev|rm|rmdir|rsync|screen|scp|sdiff|sed|seq|service|sftp|shift|shopt|shutdown|sleep|slocate|sort|source|split|ssh|stat|strace|su|sudo|sum|suspend|sync|tail|tar|tee|test|time|timeout|times|touch|top|traceroute|trap|tr|tsort|tty|type|ulimit|umask|umount|unalias|uname|unexpand|uniq|units|unrar|unshar|uptime|useradd|userdel|usermod|users|uuencode|uudecode|v|vdir|vi|vmstat|wait|watch|wc|wget|whereis|which|who|whoami|write|xargs|xdg-open|yes|zip)(?=$|\s|;|\||&)/,
            lookbehind: true
        },
        'keyword': {
            pattern: /(^|\s|;|\||&)(?:let|:|\.|if|then|else|elif|fi|for|break|continue|while|in|case|function|select|do|done|until|echo|exit|return|set|declare)(?=$|\s|;|\||&)/,
            lookbehind: true
        },
        'boolean': {
            pattern: /(^|\s|;|\||&)(?:true|false)(?=$|\s|;|\||&)/,
            lookbehind: true
        },
        'operator': /&&?|\|\|?|==?|!=?|<<<?|>>|<=?|>=?|=~/,
        'punctuation': /\$?\(\(?|\)\)?|\.\.|[{}[\];]/
    };

    var inside = insideString.variable[1].inside;
    inside['function'] = Prism.languages.bash['function'];
    inside.keyword = Prism.languages.bash.keyword;
    inside.boolean = Prism.languages.bash.boolean;
    inside.operator = Prism.languages.bash.operator;
    inside.punctuation = Prism.languages.bash.punctuation;
})(Prism);
