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1, before the installation of the relevant descriptionEssential Packages and tools1 GCC 5. Starting at 6, you need to compile with g++ . 2 cmake 5. 5 beginning with CMake for project management, CMake requires more than 2.8 versions. 3 bison

1. When a string is used more frequently in a script and the string length is long, you should use a variable instead2. Variables are essential when using conditional statements3. When referencing the result of a command, replace it with a variable4.

Scene:The Redis keys value needs to be monitored, and monitoring scripts are executed using the Crond cycle. If there is an exception, notify by email.First, install the MSMTPDownload softwarewget http://sourceforge.net/projects/msmtp/files/msmtp/1.4

[Email protected] ~]# cd/install/[[email protected] install]# mkdir-p test && CD test-S modification Time:[[Email protected] test]# DateThursday, November 30, 2017 21:55:03 CST[[Email protected] test]# Date ' +%f%T%A 'Thursday, November 30, 2017 21:5

8.1 First Test "/etc/vsftpd", "/etc/hosts" is the directory, and through the "$?" Variable view returns a status value to determine the test result.[Email protected] ~]# [-D/ETC/VSFTPD][[email protected] ~]# echo $?0[Email protected] ~]#

Integer test: Do numeric size and equality comparisons$A-lt $B: Indicates whether it is less than$A-gt $B: Indicates whether it is greater than$A-le $B: is less than or equal to$A-gt $B: is greater than or equal to$A-eq $B: Indicates whether it is

Arithmetic operatorsSet Variable a=10,b=4+ Addition[[Email protected] ~] # echo $[$a + $b]14-Subtraction[[Email protected] ~] # echo $[$a-$b]6* Multiplication[[Email protected] ~] # echo $[$a * $b]40/division, because is divisible, so only equals 2[[

Shell languageScript: Can run, a file, can implement some function (command stacking)[Email protected] ~]# vim/root/stu.shecho Hello WorldCat/etc/redhat-releaseUname-rHostnameIfconfig | Head-2[Email protected] ~]# chmod +x/root/stu.sh[Email

Http://guodayong.blog.51cto.com/263451/d-2 Guo Dayong's Blog1: Modify the configuration fileOpen the comment in front moduleload Ppolicy.lamodulepath/usr/lib/openldapmodulepath/usr/lib64/openldap also precede the database config with these two

Foreword: It is difficult to write all the code in sequential order when it is hard to satisfy the requirements when facing various lists and repeating tasks. Use other program control structures such as loops, branches, and more to make it easier