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Your question will be closed as it’s not a real question but you’ll find a lot documentation about regular expression (abbreviated regex or regexp) on Internet and on StackOverflow but here a beginning.<\/p>\n
Following information comes from Wikipedia<\/a>… . matches any single character<\/strong> [ ] matches a single character that is contained within the brackets<\/strong> [^ ] matches a single character that is not contained within the brackets<\/strong> ^ matches the starting position within the string.<\/strong> In line-based tools, it matches the starting position of any line.<\/p>\n $ matches the ending position of the string or the position just before a string-ending newline.<\/strong> In line-based tools, it matches the ending position of any line.<\/p>\n ( ) defines a marked subexpression.<\/strong> The string matched within the parentheses can be recalled later (see the next entry, \\n).<\/p>\n \\n matches what the nth marked subexpression matched<\/strong>, where n is a digit from 1 to 9.<\/p>\n * matches the preceding element zero or more times<\/strong> {m,n} matches the preceding element at least m and not more than n times<\/strong>
\nhttp:\/\/regexone.com<\/a> will help you learning regex with lessons.<\/p>\n
\nMetacharacters:<\/h1>\n
\nFor example a.c matches “abc”, etc., but [a.c] matches only “a”, “.”, or “c”.<\/p>\n
\nFor example, [abc] matches “a”, “b”, or “c”. [a-z] specifies a range which matches any lowercase letter from “a” to “z”. These forms can be mixed: [abcx-z] matches “a”, “b”, “c”, “x”, “y”, or “z”, as does [a-cx-z].<\/p>\n
\nFor example, [^abc] matches any character other than “a”, “b”, or “c”. [^a-z] matches any single character that is not a lowercase letter from “a” to “z”.<\/p>\n
\nFor example, ab*c matches “ac”, “abc”, “abbbc”, etc. [xyz]* matches “”, “x”, “y”, “z”, “zx”, “zyx”, “xyzzy”, and so on. (ab)* matches “”, “ab”, “abab”, “ababab”, and so on.<\/p>\n
\nFor example, a{3,5} matches only “aaa”, “aaaa”, and “aaaaa”. This is not found in a few older instances of regular expressions. BRE mode requires {m,n}.<\/p>\n
\nExamples:<\/h1>\n
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