The third operation of Linux operation and maintenance class

First, find the line in the/etc/rc.d/init.d/functions file followed by a set of parentheses, such as: Hello ();

# Cat/etc/rc.d/init.d/functions | grep ' [[: alpha:]].* () '

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Use the echo command to output an absolute path, use grep to remove its base name, and expand: Take out its path name;   

# echo/etc/sysconfig/network-scripts |grep ' ^/[[:alpha:]]\+[^/] '

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# Echo/proc/meminfo | Grep-o ' \b/.* '

Third, find out the ifconfig command results in the number between 1-255;

# ifconfig| Grep-e ' \b ([0-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5]) \b '

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To find files that are not owned by the master or group on the current system;

# find/\ (-nouser-o-nogroup \)-ls

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Find files or directories on the current system that are not owned by the master or group and have been visited in the last 3 days;

# Find/\ (-nouser-o-nogroup \)-a-atime-3-ls

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V. Find all files that are larger than 1M in the/etc directory and are of the normal file type;

# find/etc-type f-a-size +1m-ls |

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Six, the search/ETC/INIT.D directory, all users have execute permissions, and other users have write permission files;

# find/etc/init.d-perm-113-ls

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vii. Find files whose contents have been modified and are not root or Hadoop for the last week in/etc directory;

# find/etc-not \ (-user root-o-user hadoop\)-a-ctime-7-ls

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Copy the/etc/rc.d/rc.sysinit file to the/tmp directory and add # to the beginning of the line at least one whitespace character in the/tmp/rc.sysinit file;

copy files first

# cp/etc/rc.d/rc.sysinit/tmp

Then use the Vim editor, with the expression ":%s/^[[:space:]" in the last-line mode to replace the/#&/

# Vim/tmp/rc.sysinit

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Delete the # and white space characters in the/tmp/rc.sysinit file that begin with # and followed by at least one white-space character;

using the Vim editor, the last-line mode is replaced by the expression ":%s/^#[[:space:]]\ (. *\)/\1/"

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Change the last 0 of all enabled=0 or gpgcheck=0 in the/etc/yum.repos.d/centos-media.repo file to 1;

Replace with expression "%s/\ (. *\) =0/\1=1/"

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Xi. Weekly 2,4,6 backup/var/log/messages file to/backup/messages_logs directory, the saved file name is like messages-20161202;

# crontab-e

0 2 * * 2,4,6 root tar-cjf/backup/messages_logs/messages-' Date +%y%m%d '. tar.xz/var/log/messges

12, every two hours every day to take the current system/proc/meminfo file all the information in the beginning of S to the/stats/memory.txt file;

# crontab-e

0 */2 * * * Root Cat/proc/meminfo | grep ' ^s ' >/stats/memory.txt

13, write a script to create user10-user19; password and user name;

# vim useradd.sh

#/bin/bash

# Test Add ten Users

#

Declare-i I

For i in {10..19}

Do

if (ID user$i &>/dev/null); Then

Echo ' the user$i exist. '

Else

Useradd user$i >/dev/null

echo ' user$i ' | passwd--stdin user$i>/dev/null

Echo ' Adduser finished. '

Fi

Done

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This article is from the "Linux High-end training" blog, please be sure to keep this source http://hhclab.blog.51cto.com/6743827/1900048

The third operation of Linux operation and maintenance class