Grep advanced application 10

1. grep:

-V: displays rows that are not matched by the pattern;

-I: case insensitive;

-O: only the matched strings are displayed;

For example, ifconfig | grep 'inet addr: [^ [: space:] ';

Ifconfig | grep -- color = auto-o 'inet addr: [^ [: space:] * ';

Ifconfig | grep -- color = auto-o 'inet addr: [^ [: space:] * '| cut-d:

-F2 | grep -- color = auto-v '2017. 0.0.1 ';

-A num: after the specified row is displayed, multiple num rows are displayed;

-B num: after the specified row is displayed, the num row is displayed first;

-C num: displays the num rows before and after the specified row;

2. quotation marks

Grep 'pattern'

Grep "PATTERN"

The difference between the two is that if there is a variable, you can use "" and other single double quotation marks;

3. Exercise

A. display the rows starting with "s" of the/proc/meminfo file with no size difference;

Grep -- color = auto-I '^ s. *'/proc/meminfo;

B. display the rows ending with nologin in/etc/passwd;

Grep -- color = auto'nologin $ '/etc/passwd;

C. The/etc/inittab starts with #, followed by one or more white spaces, followed by any non-

Blank line;

Grep -- color = auto' ^ # [[: space:] $]. * [^ [: space:] '/etc/inittab

D. The/etc/inittab displays the rows of a number (that is, a number between two colons;

Grep -- color = auto': [[: digit:]: '/etc/inittab

E. display the lines starting with one or more blank characters in the/boot/grub. conf file;

Grep -- color = auto' ^ [: space:]. * '/boot/grub. conf;

F. display the/etc/inittab file that starts with a number and ends with a number that is the same as the starting number

Line;

Grep -- color = auto' ^ [0-9]. * [0-9] '/etc/inittab or

Grep -- color = auto' \ (^ [0-9] \). * \ 1 '/etc/inittab;

This article is from the blog "Nick Liu's blog", please be sure to keep this source http://zkhylt.blog.51cto.com/3638719/1302204