grep例子（Grep example）.docVIP

grep例子（Grep example） Grep regular expression element character set: Begin to anchor for ^ such as:^grep, all with grep at the beginning of the line. $anchor end of line such as:grep$, all grep at the end of the line. Matching. A non newline characters such as:gr.p, GR followed by an arbitrary character, then is p. * matches zero or more previous characters such as:*grep, all one or more spaces followed by grep lines. Together with representatives of any character. [], a specified range of characters, such as[Gg]rep, Grep and grep. [^], one that is not in the specified range of characters, such as:[^A-FH-Z]rep, A-R and T-Z at the beginning does not contain a letter, followed by rep lines. (..\) \ tag matching characters, such as \ , love (love\) is marked as 1. To anchor words such as: \ \, contains words starting with grep line. The end of \ anchor words, such asgrep\, contains the grep at the end of the word line. Repeat x\{m\} characters x, m, such as0\{5\}, contains 5 o line. X\{m, \} repeat character x, at least m times, such as:o\{5, \}, there are at least 5 o lines. X\{m, n\} repeat character x, at least m times, not more than n times, such as:o\{5,10\}, 5--10 for O. \w, text and numeric characters, namely the [A-Za-z0-9], such as:G\w*p, G followed by zero or more text or numeric characters, then P. \b word lock symbol, such as:\bgrep\b, grep. The grep option is used: The number of -c output matching line. -i insensitive (only applicable to single character). -h query file does not display the file name. -l query file contains only output character file name. -n display and matching line line number. -s does not exist or no, display the error message text. -v does not contain all the matching text. -V software version information The use of grep, when best to use double quotes to prevent being mistaken for system parameters or special order, also can match multiple words. A matching instance: Grep -c 48 test.txt 48 to all statistical character at the beginning