Shell

This article takes the shell from getting started to giving up the first stepThus, continue from small white to give up the second part of @[email protected] First, the shell operator The shell supports a number of operators, including:

The first part,1. View TCP connection StatusNetstat-nat |awk'{print $6}'|sort|uniq-c|sort-Rnnetstat-N | Awk'/^tcp/{++s[$NF]}; END {for (a in S) print A, S[a]}'netstat-N | Awk'/^tcp/{++state[$NF]}; END {for (key in) print key, "\ T",

Suppose we define a variable as:File=/dir1/dir2/dir3/my.file.txtWe can replace each other with ${} to get different values:${file#*/}: Take out the first/its left string: dir1/dir2/dir3/my.file.txt${file##*/}: Take out the last/and left string:

7.1 Creating and executing shell programs 1487.2 Variables 1497.2.1 Assigning a value to a variable 150The shell uses "=" To assign a variable, or you can change or initialize the value of a variable with an equal sign.7.2.2 Access Variable 1507.3

1. View the native supported shell types, cat/etc/shells. /bin/bash is the default shell for Linux2.bash Shell function Command memory function history (file address ~/.bash_history) tab command complement function alias command aliases set function

1. ENV (environment abbreviation) and export Show all environment variables 2. Description of Environment variables environment variable home" user home folder equivalent to "~" shell

1) How do I pass parameters to a script?./script argumentExample : Show file name script./show.sh File1.txtcat Show.sh#!/bin/bashcat $2) How do I use parameters in a script?First parameter: $ $, second argument: $ AExample: The script will copy the

Quick start from official Hbase HBase (main):003:0> create ' test ', ' CF ' 0 row (s) in 1.2200 secondshbase (main):003:0> list ' test ': 1 row (s) in 0.0550 secondshbase (main):004:0> put ' test ', ' row1 ', ' cf:a ', ' value1 ' 0 row (s) in 0.

After learning the shell script to get started, slowly try to write some scripts to practice practiced hand, in this first simple learning to write a system memory monitoring.1, first of all to determine the need to take a look at the memory usage

the role of the shell is to convert a user-entered text command into an internal nuclear identification data instruction to the kernel for execution, and the kernel needs to be translated into binary to be executed by the CPU bottomthe user

Debugging a serial port under Linux is a hassle, especially in an embedded environment, and many times it is time to debug with another device.Here to figure out a feasible serial debugging method, you can simply check whether the serial port is

1. Regular expressionsIn fact, it is a specification, that is, the pattern, constraint string, and so on what kind of format, such as the requirement that the string must begin with a, t end, strings that meet such conditions will use the regular

Shell programming variables a bash variable and variable classificationBash is a standard shell in Linux, so it's often called bash as a shell.1. Variable naming rules Variable names can consist of letters, numbers, underscores, but must

Variable name: Use English, Numbers and _ (underscore), the beginning can not be a number, length unlimited, strictly case-sensitiveVariable settings: variable name = variable ValueNote: No spaces on both sides of the equals signYou can enclose the

Deletion of shell variables:[Email protected]:~$ Path=${path} # #设置path和PATH相同内容 [email protected]:~$ echo $path/usr/local/sbin:/usr/local/bin:/ Usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games[email protected]:~$ echo ${path#/*sbin:} # #加上 '

I see Shell the first eye1 , script interpreter settingsfirst line of the script: #!/bin/sh[email protected] sun]# cat test.sh#!/bin/shFirst Firstrows can be split into two parts,#!and absolute paths,#!It's just a special notation,#!The interpreter

Suppose we define a variable as:File=/dir1/dir2/dir3/my.file.txtDifferent values can be replaced with ${}, respectively:${file#*/}: Delete the first/its left string: dir1/dir2/dir3/my.file.txt${file##*/}: Remove the last/and left string: my.file.txt$

There are several ways to bash a shell script, and now make a summary. Suppose we write a good shell script with the file name hello.sh, the file location in the/data/shell directory and have execute permissions.Method One: Switch to the directory

The color of the text terminal can be generated by using the ANSI unconventional character sequence. Example:Echo-e "\033[44;37;5m ME \033[0m COOL"The above command sets the background to blue, foreground white, blinking cursor, output character "ME"

Definition of the array:Array name = (element 1 element 2 element N) # A pair of parentheses indicates an array, and the elements of the array are separated by a "space" symbol.Example: myarray= (1 3 5 7 9) # Note the method defined, parentheses,