Shell

Take the CentOS system as an example to realize automatic database backup.1. Write a shell: 12 #! /bin/bashMysqldump -cp --user=root --password=' 123 ' dbName | gzip > ~/db/dbname -'date +%y%m%d%H '. SQL. GZ ;

Use the-e parameter of MySQL can perform various kinds of SQL (create, delete, add, erase, change, check) and other operationsUsageMysql-uxxx–pxxx-e "MySQL Command" Of course, you can also use the following notation MYSQL-E-uxxx–pxxx "mysql

Defining variablesA=Assigning values to variablesA=5' Number equals $ ()[Email protected] ~]# hostnameLocalhost.localdomain[Email protected] ~]# a= ' hostname '[Email protected] ~]# echo $aLocalhost.localdomain${-} to determine whether the variable

The nature of the shell The shell of the Linux system is equivalent to the "one shell" of the operating system, which is the command language interpreter, which provides the user with an interface to use the operating system. It does not belong to

Original blog, reproduced please indicate the sourceThe shell is the command interpreter.See which shells are supported by this system1 Tab Command completionThis almost every time can be used, for example, I have a file called file.txt, assuming

Of course this blog original code is reproduced great God's ...Automatically install Nginx script, use case mode, choose the way, you can change to the actual needs of the script you want mynginx.sh #!/bin/sh # # #nginx Install Shell # # #

SummaryThis chapter describes how to use ls and stat to expose files and file meta data , and how to use Touch set the time stamp not seen . Touch can display information about datetime and scope limitations on many existing systems .Shows how to

Today, a friend suddenly asked me in the shell, how to compare floating point and integer, but I asked a Leng, in the work did not encounter this scene. We also know that the calculation of numbers in the shell is usually converted to integers, such

Using SH to write small scripts can make the job easier. Part of the content may be more unfamiliar to everyone (at least I am).is the variable related to the expansion, the following are some simple description and use of the method. To make the

Add 20 users to the CLASS01 group in bulk, the user name begins with STD, ends with a number, format: STD01---STD20Method 1#!/bin/shgroupadd class01a=stdfor ((i=1;iMethod 2:#!/bin/bashgroupadd class01for i in {1..20}doif [$i-lt];thenuseradd "std0$i"-

Cat: View the contents of a file, connect a file, create one or more files, and redirect output to a terminal or file usage: cat [options] [file]1. $ Cat Hello.txtdisplaying content in a hello.txt text file2. $ cat-n File-N option to display the

#!/bin/bashRead-t 30-p "Please input user name:" NameRead-t 30-p "Please input user number:" numRead-s-T 30-p "Please input user password:" PassEcho-e "\ n"if [!-Z "$name"-A!-Z "$num"-A!-Z "$pass"]ThenY=$ (echo "$num" | sed-e ' s#^[0-9]# #g; s#[0-9]*

File comparison Operators-e filename true if filename exists [-e/var/log/syslog]-D filename True if filename is a directory [-d/tmp/mydir]-F filename True if filename is a regular file [-f/usr/bin/grep]-L filename True if filename is a symbolic link

For loopapplist= (App1 app2 app3); for apps in ${applist[@]};d o echo $app;d one; Get IP AddressIfconfig |grep-po ' (? Ifconfig|awk-f "[:]+" ' $4~/[0-9].+[^0-9]+/{print $4}/lo/{exit} 'Ifconfig|sed-nr ' s/^[[:space:]]+inet addr: (. *) bcast.*/\1/p '

Sometimes the shell has a variable number of arguments, want to get the 2nd bit after the argument, as a new entry to invoke other scripts the usual way to think of this is to use traversal, for example, the following method:For ((i=2;i DoEcho $i

Today to write blog only to find before there is no written, my God, I was asleep ...1, what is a shell?The shell is a unix/linux system with software that acts as an interface between the kernel and the user, reads the user's input command, sends

1. Regular expressions1) ^ Start * Previous character repeats more than 0 times+ More than 1 times? 0 or 1 times. An arbitrary character (. *){m,n} m to n times[0-9] [A-z] any number or letter$ end Character2) sed and awk commandsSed ' match

1 /**2 * Run shell scripts3 * @paramShell scripts that the shell needs to run4 */5 Public Static voidExecshell (String shell) {6 Try {7Runtime RT =runtime.getruntime ();8 rt.exec (shell);9}Catch(Exception e) {Ten

#SIZE 10Direct Insert Sortvoid Insert_sort () {int i,j;int array[size+1];ARRAY[]={0,12,23,11,55,2,34,18,20,48,22};for (i=2;iArray[0]=array[i];J=i-1;while (Array[0]ARRAY[J+1]=ARRAY[J];j--;}ARRAY[J+1]=ARRAY[0];}}Binary Insert Sortvoid

#SIZE 10Direct Insert Sortvoid Insert_sort () {int i,j;int array[size+1];ARRAY[]={0,12,23,11,55,2,34,18,20,48,22};for (i=2;iArray[0]=array[i];J=i-1;while (Array[0]ARRAY[J+1]=ARRAY[J];j--;}ARRAY[J+1]=ARRAY[0];}}Binary Insert Sortvoid