Linux OPS Engineer Essentials (command)

1. How to filter out all the first level directories in the following directory

[email protected] ~]# LL

Total 16

-rw-r--r--1 root root 0 Jul 5 11:43 111

-rw-r--r--1 root root 0 Jul 5 11:43 222

-rw-r--r--1 root root 0 Jul 5 11:43 333

Drwxr-xr-x 2 root root 4096 Jul 5 11:43 AAA

Drwxr-xr-x 2 root root 4096 Jul 5 11:43 BBB

Drwxr-xr-x 2 root root 4096 Jul 5 11:43 CCC

Drwxr-xr-x 2 root root 4096 Jul 5 11:43 DDD

Method 1:ls-l The result is a directory that begins with D

D[[email protected] ~]# ls-l |grep ^d drwxr-xr-x 2 root root 4096 Jul 5 11:43 aaadrwxr-xr-x 2 R by filtering the start file with long format output  oot root 4096 Jul 5 11:43 bbbdrwxr-xr-x 2 root root 4096 Jul 5 11:43 cccdrwxr-xr-x 2 root root 4096 Jul 5 11:43 ddd Hint: ^ : To ... Beginning

Method 2: Filter out the directory by labeling the directory and filtering the identity

[[email protected] ~]# ls-f #把目录结尾加上 "/", easy to distinguish and filter out, ls-p can also let the directory with a slash 111 222 333 Aaa/bbb/ccc/ddd/[[email protected ] ~]# ls-f|grep/$ #把包含斜线 "/" filtered out is the catalogue aaa/bbb/ccc/ddd/

Application of 3:find method

[[email protected] ~]# find. -type D #. Represents the current directory./aaa./ccc./bbb./ddd

Method 4:tree

[Email protected] ~]# tree-dl.| --aaa|--bbb|--CCC '--DDD

Filter lines that start with a blank line and #

[Email protected] ~]# Grep-ev "^#|^$"/etc/init.d/sshd [[email protected] ~]# egrep-v "^#|^$"/etc/init.d/sshd Comment:-E # Egrep-v #过滤 ^# #井号开头 ^$ #空行

Method 5:sed

[[email protected] ~]# Ls-l|sed-n/^d/pdrwxr-xr-x 2 root root 4096 Jul 5 11:43 aaadrwxr-xr-x 2 root root 4096 Jul 5 11 : bbbdrwxr-xr-x 2 root root 4096 Jul 5 11:43 cccdrwxr-xr-x 2 root root 4096 Jul 5 11:43 ddd Note:-N #拒绝默认输出p #打印

Method 6:awk

[[Email protected] ~] #ls-l|awk '/^d/{print $} ' drwxr-xr-x 2 root root 4096 Jul 5 11:43 aaadrwxr-xr-x 2 root root 4096 J UL 5 11:43 bbbdrwxr-xr-x 2 root root 4096 Jul 5 11:43 cccdrwxr-xr-x 2 root root 4096 Jul 5 11:43 DDD

2. If the current directory is

[Email protected] ~]# pwd #这是打印当前目录/root

Now because you need to enter the/TMP directory to operate, the following commands are executed:

[[email protected] ~]# pwd/root[[email protected] ~]# Cd/tmp/[[email protected] tmp]# CD-/root[[email protected] ~]#

Principle:

[Email protected] ~]# env|grep-i oldpwd #是这个变量记录着上一次的目录OLDPWD =/tmp

3. There are a lot of files in a directory (LS viewing a lot of screen), want to see the fastest speed to the most recent files. If you look?

Answer:

[[email protected] etc]# LS-LRT #执行这个命令后最新的文件会在最下面 # Reverse the modified time file and directory in long format so that the recently created or modified file or directory-T #按修改时间-R #翻转

4. When configuring Apache, execute the./confiure--prefix=/application/apache2.2.17 to compile Apache after make Installl is finished, you want the user's access path to be simpler, need to give/ The application/apache2.2.17 directory makes a soft link/application/apache that allows internal developers or managers to access the/apache installation directory via/application/apache application/apache2.2.17 the content, please give the implementation of the command (hint: Apache for an HTTP Web service)

[[email protected] ~]# ln-s/application/apache2.2.17/application/apache #-s parameter is represented as creating a soft link

5. The access logs for Apache services are known to be logged by day in the server local directory/data/logs, and because of the tight disk space, it is now required to keep only the last 7 days of access logs! How can I resolve this? Please provide a workaround or configure or process the command.

-rw-r--r-- 1 root root   0 jun 28 00:00 2017-06-29_00-00. backstage_access.log-rw-r--r-- 1 root root   0 jun 28 00:00  2017-06-29_00-00.backstage_error.log-rw-r--r-- 1 root root   0 jun 29  00:00 2017-06-30_00-00.backstage_access.log-rw-r--r-- 1 root root   0  jun 29 00:00 2017-06-30_00-00.backstage_error.log-rw-r--r-- 1 root root    0 jun 30 00:00 2017-07-01_00-00.backstage_access.log-rw-r--r-- 1  root root   0 jun 30 00:00 2017-07-01_00-00.backstage_ error.log-rw-r--r-- 1 root root   0 jul  1 00:00  2017-07-02_00-00.backstage_access.log-rw-r--r-- 1 root root   0 jul   1 00:00 2017-07-02_00-00.backstage_error.log-rw-r--r-- 1 root root   0 jul  2  00:00 2017-07-03_00-00.backstage_access.log-rw-r--r-- 1 root root   0  Jul  2 00:00 2017-07-03_00-00.backstage_error.log-rw-r--r-- 1 root root    0 jul  3 00:00 2017-07-04_00-00.backstage_access.log-rw-r--r--  1 root root   0 jul  3 00:00 2017-07-04_00-00. backstage_error.log-rw-r--r-- 1 root root   0 jul  4 00:00  2017-07-05_00-00.backstage_access.log-rw-r--r-- 1 root root   0 jul   4 00:00 2017-07-05_00-00.backstage_error.log-rw-r--r-- 1 root root    0 jul  5 00:00 2017-07-06_00-00.backstage_access.log-rw-r--r-- 1  root root   0&nbsp jul  5 00:00 2017-07-06_00-00.backstage_error.log[[email protected] ~]#  find ./ -type f -name  "*.log"  -mtime +7|xarge rm -f      #删除7天

Find finds time-related parameters:

-atime n #n为数字, meaning the file that was accessed by access in "one day" prior to n days;

-ctime n #n为数字, meaning a file that has a change in "one day" prior to n days

-mtime N #n is a number, meaning a file that was modification in "one day" before N days

-newer file #file As an existing file, meaning that as long as the file is newer than file, it will be listed.

Find./Type F-name "*.log"-mtime +7|xargs rm-f

6. When debugging the system service, want to be able to view the system log/var/log/messages update in real time, how to do?

Law One:

[[email protected] ~]# tail -f /var/log/messages    jul   6 14:51:40 localhost yum[29341]: installed: gnome-vfs2-devel-2.24.2-8.el6.x86_ 64jul  6 14:51:41 localhost yum[29341]: installed:  dmz-cursor-themes-0.4-4.el6.noarchjul  6 14:51:41 localhost yum[29341]:  installed: system-gnome-theme-60.0.2-1.el6.noarchjul  6 14:51:41 localhost yum[ 29341]: installed: libgnome-2.28.0-11.el6.x86_64jul  6 14:51:41 localhost  yum[29341]: installed: libgnome-devel-2.28.0-11.el6.x86_64jul  6 14:51:41  Localhost yum[29341]: installed: libbonoboui-2.24.2-3.el6.x86_64jul  6 14:51:42  localhost yum[29341]: installed: libbonoboui-devel-2.24.2-3.el6.x86_64jul  6  14:51:42 localhost yum[29341]: installed: libgnomeui-2.24.1-4.el6.x86_64jul  6 14:51:42 localhost yum[29341]:  installed: libgnomeui-devel-2.24.1-4.el6.x86_64jul  6 14:51:43 localhost yum[ 29341]: updated: glib2-2.28.8-9.el6.i686

Law two:

[[email protected] ~]# tail -f /var/log/messages  jul  6  14:51:40 localhost yum[29341]: installed: gnome-vfs2-devel-2.24.2-8.el6.x86_64jul   6 14:51:41 localhost yum[29341]: Installed:  dmz-cursor-themes-0.4-4.el6.noarchjul  6 14:51:41 localhost yum[29341]:  installed: system-gnome-theme-60.0.2-1.el6.noarchjul  6 14:51:41 localhost yum[ 29341]: installed: libgnome-2.28.0-11.el6.x86_64jul  6 14:51:41 localhost  yum[29341]: installed: libgnome-devel-2.28.0-11.el6.x86_64jul  6 14:51:41  Localhost yum[29341]: installed: libbonoboui-2.24.2-3.el6.x86_64jul  6 14:51:42  localhost yum[29341]: installed: libbonoboui-devel-2.24.2-3.el6.x86_64jul  6  14:51:42 localhost yum[29341]: installed: libGnomeui-2.24.1-4.el6.x86_64jul  6 14:51:42 localhost yum[29341]: installed:  libgnomeui-devel-2.24.1-4.el6.x86_64Jul  6 14:51:43 localhost yum[29341]:  updated: glib2-2.28.8-9.el6.i68

Law Three:

[[email protected] ~]# tailf /var/log/messages jul  6 14:51:40  localhost yum[29341]: installed: gnome-vfs2-devel-2.24.2-8.el6.x86_64jul  6  14:51:41 localhost yum[29341]: installed: dmz-cursor-themes-0.4-4.el6.noarchjul   6 14:51:41 localhost yum[29341]: Installed:  system-gnome-theme-60.0.2-1.el6.noarchjul  6 14:51:41 localhost yum[29341]:  INSTALLED: LIBGNOME-2.28.0-11.EL6.X86_64JUL  6 14:51:41 LOCALHOST YUM[29341]:  Installed: libgnome-devel-2.28.0-11.el6.x86_64Jul  6 14:51:41 localhost  Yum[29341]: installed: libbonoboui-2.24.2-3.el6.x86_64jul  6 14:51:42 localhost  yum[29341]: installed: libbonoboui-devel-2.24.2-3.el6.x86_64jul  6 14:51:42  localhost yum[29341]: installed: libgnomeui-2.24.1-4.el6.x86_64jul  6 14:51:42 localhost yum[29341]: installed:  libgnomeui-devel-2.24.1-4.el6.x86_64jul  6 14:51:43 localhost yum[29341]:  updated: glib2-2.28.8-9.el6.i686

7. How do I print the line number and content of the nginx.conf content of the configuration file?

Act 1:

[Email protected] conf]# NL nginx.conf 1 user nginx;     2 worker_processes 4;     3 4 #pid/var/run/nginx.pid;     5 6 Events {7 Worker_connections 5000;     8 #use Epoll; 9} ........ .......

Act 2:

[Email protected] conf]# cat-n nginx.conf 1 user nginx;     2 worker_processes 4;     3 4 #pid/var/run/nginx.pid;     5 6 Events {7 Worker_connections 5000;     8 #use Epoll; 9} 10 ..... .............

Act 3:

[[Email protected] conf]# less -n nginx.conf      1  user  nginx;      2 worker_processes 4;       3       4  #pid  /var/run/nginx.pid;       5       6 events {       7     worker_connections  5000;       8      #use  epoll;      9 }      10      11 http {      12     include       mime.types;      13     default_type  application/octet-stream;      14

The 4:vi file is then executed: Set NU,: Set Nonu to cancel line number

This article is from the "Little Rookie" blog, please be sure to keep this source http://baishuchao.blog.51cto.com/12918589/1945114

Linux OPS Engineer Essentials (command)