Shell

First, what is the bean Shell BeanShell is a scripting language that conforms fully to the Java syntax specification and has its own syntax and methods. BeanShell is a loosely typed scripting language (this is similar to JS);

[Email protected] zuoye]#CatQuansges.SH #!/bin/Bash>file[ ! $#-ge3] &&Echo "Please input three number or more number!"&& exit2||Echo$* >file forIinch$* Do Expr$i +1&>/dev/NULL [ $? -ne0] &&Echo "Input is error"&&Exit Donea=`Cat file|Xargs-n1|Sort-

loop control and functionsBreak loop control, continue loop control.Loop control characterThe break loop control can be used to exit the entire loop;After exiting the loop, the following loops are executed, using the Continue loop

1. Shell Script ProgramThe shell is the "shell" of the operating system, and the shell provides users with a human-computer interface. All the user's actions on the computer and the data that the computer obtains are managed by the shell.Shell

Reprint please indicate http://www.cnblogs.com/winifred-tang94/There are three types of variables in the shell environment:A, environment variables; You can refer directly to the shell script in the form of "environment variable name".b,

Shell scripting is one of the skills that Linux OPS engineers have to master, and the use of shell scripts allows us to better operate Linux systems and facilitate our execution.One, the basics of programmingBASIC Programming ConceptsProgramming

Select loopMainly used to create menus, the menu items arranged numerically are displayed on the standard output, and the PS3 indicator is displayed, waiting for the user to enter a number from the user input menu list, execute the corresponding

1.BASH (Bourne again Shell)cmd1; cmd2 equals to CMD1CMD22.echo Music; The semicolon is not printed because the semicolon defaults to the command-bound symbol3. Use Pgrep to identify process environment variables[Email protected] shell]$ pgrep compiz4

Conditional Judgments in shell scripts 1.if [Condition];thenStatementFi2.If [Condition];thenStatementelif [Condition];thenStatementElseStatementFi Note the point:1-1. If and fi are paired, a syntax error occurs when

What are positional variablesCalls the arguments passed to the script through the command line in the script code.What are the positional variables$1,$2,...: Corresponding to the 1th and 2nd parameters, Shift [n] position $: The command itself $*:

Shell variable shell supports three types of variables User-defined variables: User-defined variables, variable names begin with an English letter or underscore, and are case-sensitive. Positional variables: Variables that are passed to

Shell script for disk partition formattingOur shell scripting structure is divided into sequential structure, selection structure and loop structure, we have previously introduced the selection structure including if, case statements, loop structure

Syntax for While loop: While condition testDoCommand AreaDone Example:#!/bin/bashdeclare-i i=1declare-i Sum=0while ((iUse while to read file contentsWhile loop, the classic usage is to go with the switch input, read the contents of the

Read interaction [[[email protected] shell-test]# vim read.sh[[email protected] shell-test]# vim read.sh[[email  Protected] shell-test]# lltotal 52-rw-r--r--1 root root 0 Jul 00:52 012-rw-r--r--1 root root 201 Jul 19:04 2-r w-r--r--1 root root 0

Functions: functionProgram programming: Code reuse;Modular programming;Structured programming;Consider the code of an independent function as a whole, and take a name for it; a named code snippet, which is a function;Definition and use of

The character color of terminal is controlled by escape sequence, it is the system display function in text mode, and the specific language is independent, Shell,python,perl and so on can be called.The escape sequence starts with the ESC and can do

One, Shell scriptPre-placed in a file with a variety of commands to facilitate one-time execution of a program text; some shell syntax and instructions are written inside, and then the functions such as formal notation, pipeline commands, and data

#需求Write a backup script that backs up Samba files for 20 days#!/bin/bashdir= "/samba/operations" backup= "/data" filename= "operations.tar.bzip2" date= ' Date +%y%m%d ' [!-e "$dir"] && echo "Please contact admin" && exit[!-e "$backup" && mkdir

Custom variables: There are variables that are defined by the system user, only valid in the user's own shell environment, also known as local variables, and when shell scripting is programmed, certain custom variables are usually set to suit the

There is a log file on the server Guest.log, each line contains: ID number, name, Internet café Name, the most recent Internet time, Internet hours, the amount of consumption, now requires the file of each row of the sixth column and the second