update elements and fix some bugs

lib/src/prism/components/prism-bash.js

-Prism.languages.bash = Prism.languages.extend('clike', {
-        'comment': {
-                pattern: /(^|[^"{\\])#.*/,
-                lookbehind: true
-        },
-        'string': {
-                //allow multiline string
-                pattern: /("|')(\\?[\s\S])*?\1/,
-                inside: {
-                        //'property' class reused for bash variables
-                        'property': /\$([a-zA-Z0-9_#\?\-\*!@]+|\{[^\}]+\})/
-                }
-        },
-        // Redefined to prevent highlighting of numbers in filenames
-        'number': {
-                pattern: /([^\w\.])-?(0x[\dA-Fa-f]+|\d*\.?\d+([Ee]-?\d+)?)\b/,
-                lookbehind: true
-        },
-        // Originally based on http://ss64.com/bash/
-        'function': /\b(?: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|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)\b/,
-        'keyword': /\b(if|then|else|elif|fi|for|break|continue|while|in|case|function|select|do|done|until|echo|exit|return|set|declare)\b/
-});
+(function(Prism) {
+        var insideString = {
+                variable: [
+                        // Arithmetic Environment
+                        {
+                                pattern: /\$?\(\([\w\W]+?\)\)/,
+                                inside: {
+                                        // If there is a $ sign at the beginning highlight $(( and )) as variable
+                                        variable: [{
+                                                        pattern: /(^\$\(\([\w\W]+)\)\)/,
+                                                        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.insertBefore('bash', 'keyword', {
-        //'property' class reused for bash variables
-        'property': /\$([a-zA-Z0-9_#\?\-\*!@]+|\{[^}]+\})/
-});
-Prism.languages.insertBefore('bash', 'comment', {
-        //shebang must be before comment, 'important' class from css reused
-        'important': /^#!\s*\/bin\/bash|^#!\s*\/bin\/sh/
-});
+        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,
+                                inside: insideString
+                        },
+                        {
+                                pattern: /("|')(?:\\?[\s\S])*?\1/g,
+                                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|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);