Shell

Several cases of sqlplus and shell passing value to each otherScenario One: The simplest invocation of sqlplus in the shell$cat test.sh#!/bin/shSqlplus Oracle/[email Protected]>file.log SELECT * from Test;ExitEOF #注意EOF要顶格写$sh test.sh$cat

Sed is a good file processing tool, itself is a pipe command, mainly in the behavior of the unit processing, you can replace the data rows, delete, add, select and other specific work, the following first understand the use of SEDThe SED command

What is a function?A function is a collection of commands, represented by a name, called a function name. The function name has the same naming convention as the variable.Once the function is defined, execute the name as if it were a bash command

Edit command: Ctrl–a move cursor to beginning of line Ctrl–e move cursor to end of line Ctrl–l Clear screen (function with clear command) Ctrl–d Delete the character at the cursor location Ctrl–t the character in the position of

Due to a large number of customers under the core of the room, which unavoidably many large customers, is so-called tall tree catches, the recent computer room some customers are always traffic attacks, the prevention method can only be found

IntroductionThe shopt command allows you to set optional parameters for the shell.shopt [-PSU] [optname ...]-S turns on an option.-U turns off an option.-p lists all the options that can be set.Extglob OptionsIf the EXTGLOB option is turned on, the

1.Linux composition kernel, shell, tool program has Sh.bashAn example!#/bin/bashEcho 'Before execution chmod +xExecution./2. a little trick cp/dev/null/var/log/apache2/access.logUse/dev/null to apache2 log files in the clear sky Note: Think of

In this case, it is usually a shell script written under window and copied to the Linux machine for execution to occur.The reason is:The end of each line under Windows is \n\r, and the end of the file under Linux is \ nThis allows window to write an

The type of shell that stands in terms of user login:Log-in Shell:Log in normally via a terminalSu-usernameSu-l USERNAMENon-logon Shell:Su USERNAME (using su to switch users without any parameters)Open Command Window under GUIShell scripts that are

FS ShellThe call file system (FS) shell command should use the form Bin/hadoop FS . All of the FS shell commands use URI paths as parameters. The URI format is Scheme://authority/path. For the HDFs file system, Scheme is HDFS, to the local file

Learn from this section the main control statements, loop statementsComments, Shell Multiline commentsThe Shell line comment is simple, just add # at the beginning of each line, but he does not provide a special multi-line comment method, so we use

The difference between 1.hadoop1.0 and hadoop2.0:　　hadoop1.0 ecology such as:　　hadoop2.0 Ecology:　　2.HDFS Description: HDFs is an open source clone of Google's GFS, and the architecture of HDFs is as follows:　　1) NameNode: Manages the namespace of

Case ... Esac is similar to the switch ... case statement in other languages, and is a multi-branch selection structure.The case statement matches a value or a pattern, and if the match succeeds, the matching command is executed. The case statement

Echo is an internal command of the shell that prints the specified string on the screen. Command format: Echo Arg You can use echo to achieve more complex output format control.Show escape characters echo "\"It is a test\ ""

echo Display in shell script with color display, echo display with color, need to use the parameter-e format as follows: Echo-e "\033[word background color; text color m string \033[0m" Example: Echo-e "\033[41;36m something Here \033[0m "where 41

1. Exit statusIn a Linux system, every time a command executes, the system returns an exit state, which is stored in the variable, which is an integer value that we can determine whether the command is running correctly.Typically, the exit status

Variable Variablename=value Cannot have spaces around equals sign Variable content has a space to use "or", but v= "Hello $name" $ to maintain the original function, single quotation marks do not, v= "Hello ' $name '" plain text Use

The shell is much more programmatic in terms of programming than Windows batch processing, both in loops and operations.Bash supports one-dimensional arrays (which do not support multidimensional arrays) and does not limit the size of arrays.

Some common Shell commands and common Shell commands Common system commands] Passwd [hostname]Change Password Useradd [hostname]Add User Su-Switch to the root user Ssh [hostname]Ssh connection Cd [directory]Go to the directory Sudo chown

Shell encryption-shc Vulnerability Recently, I have been compiling Shell scripts for customers to use. I will inevitably encounter some sensitive information that I don't want them to know. So I used Shc script encryption to compile binary files