Use of grep (GO)

grep parameters

1. -C: Displays the number of matching rows (that is, how many rows match);
2. -N: Displays the line number of the document where the match is located;
3. -I: ignore case when matching;
4. -S: Error message not output;
5. -V: output mismatched content;
6. -O: output exactly match content;
7. --color: Color display of matched content
8. \: Ignore expression in Word Fu Yuan has meaning;
9. ^: The start line of the matching expression;
10. $: Matches the end line of an expression;
11. \<: Starting from the line that matches the expression;
12. \>: End of line to match expression;
13. []: Specifies the range of a single character (such as [a] that a meets the requirements);
14. [^]: matches any single character outside the specified range
15. [-]: range, such as [A-z] that is a,b,c to Z all meet the requirements;
16. . : all single characters;
17. *: All characters, length can be 0;
18. Catalog ll with-W for an exact match

description of the regular expression meta-character :

. : Matches any single character

*: Matches its preceding character any time

. *: Any character of any length

？ : matches the preceding character 1 or 0 times

\{n,m\}: Matches characters preceding it at least n times, up to M times

Location anchoring:

^: Anchor the beginning of the line, the content after this character must appear at the beginning of the line

$: Anchor the end of the line, the content before this character must appear at the end of the row

^$: Blank Line

\< or \b: Anchor word, any character following it must appear as the first word

\> or \b: anchors the ending, any character preceding it must appear as the tail of the word

Use of Grep-a,-B,-C:

1)-A NUM #grep-a 1 aa test.txt Description: Searches from Test.txt for a line with a AA style and displays the following 1 rows of the row

2)-B NUM #grep-b 1 AA test.txt Description: Search from Test.txt for a line with a AA style and display the first 1 rows of the row

3)-C NUM #grep-C 2 AA test.txt Description: Lists file in addition to the line containing the panda style and out of its top and bottom 2 lines

Use of grep (GO)