Shell

One, view memoryAndroid program memory is divided into 2 parts: native and Dalvik,dalvik are the Java heaps we normally call, the objects we create are assigned here, and bitmap are allocated directly on native, and the limit for memory is native+

#!/bin/bash# Beijing Linux Technology Exchange Group: 76109360n=0s=0for ((i=1; I /dev/null; Then Echo-e "\033[31m192.168.1. $i yes\033[0m" Let n= $n +1 else Echo-e "\033[32m192.168.1. $i No 33[0m "Let s= $s +1 fidone echo" $n Yes, $s no "Note: The

1. {} curly braces:usage One: Wildcard extensionEg:ls my_{finger,toe}sThis command is equivalent to a combination of the following commands:ls my_fingers my_toeseg:mkdir {Usera,userb,userc}-{home,bin,data}we will get Usera-home, Usera-bin,

1. Enter the HBase command line./hbase Shell2. Display the list of tables in HBase3. Create a user table with info, data two column familiesCreate ' user ', ' info1 ', ' data1 'Create ' user ', {NAME = ' info ', VERSIONS = ' 3 '}4. Insert the

(1) Distributed File systemAs the amount of data is increasing and the scope of an operating system is not enough, it is allocated to more operating system-managed disks, but it is not easy to manage and maintain, so a system is urgently needed to

Linux Auto-install JDK shell scriptA: This script runs the machine, LinuxB: The machine to install the JDK, LinuxFirst, on machine a where the script is running, you can log on to the machine B where the JDK is to be installed without SSH password,

Linux under Install configuration msmtp and mutt send mailAuthor: In-field Date: December 11, 2014 Comment (0) View CommentsLinux under Installation configuration msmtp and MuttLinux has the need to send mail, mail is uncertain, because many mail

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

The function of quotation marks1 double quotation marks ("")1) Use "" To reference any character or string except the character $ (dollar sign), ' (anti-quote), \ (backslash). Double quotation marks do not prevent the shell from special handling of

Shell Tutorial Shell echo commandShell variablesWhen defining a variable, the variable name does not have a dollar sign (required for variables in the $,php language), such as:Your_name= "w3cschool.cc"Note that there can be no spaces between the

When we write functional scripts, we tend to place functions that are similar in operation or similar in parameters into the same shell script, which is easy to manage, easy to maintain, and clear. In this case, the usual approach is to define all

In the Linux production environment, there are the following such a common operations need to work.Every once in a while, such as two hours, the log file to generate the log per second (this is assumed to be testfile.out, the absolute path

CPU Information Acquisition CPU UsageAcquisition algorithmCollect and calculate total CPU usage or single core utilization with/proc/stat files. Take cpu0 as an example, the algorithm is as follows:1. Cat/proc/stat | grep ' cpu0 ' gets cpu0 's

You often have to connect to Windows remotely, so rdesktop is a must.Recently installed the Gnome interface of the CENTOS7, found that the Rdesktop command has been used to become rdesktop-vrdp, but can be used on the line.To add a GUI to the

1. Manually parse parameters, position parameters(1) $#: Number of parameters(2) $1...$9: first parameter ... 9th parameter2. Built-in command parsing, getopts, long parameter format not supportedCommand format: getopts option_string variableThe

In the shell, arguments can be passed to a function when it is called. Inside the function body, the value of the parameter is obtained in the form of a $n, for example, $ $ for the first argument, and $ = for the second argument ...Examples of

ArrayConceptA pair of parentheses indicates an array, and the elements of the array are separated by a "space" symbol in the form: array= (value0 value1 value2 value3 ...), when the subscript of the array defaults to 0Basic operations1.arr= (1 2 3 4

Shell ProgrammingA. for Loop Build List {start number: End number} Command generation list ' seq [number of start] [step length] End number ' For L in {1..5};d oFor L in ' seq 5 ';d o1 to 100 of the cumulative sum and1

The terminal on Mac uses the Bourne-again shell command, bash for short. Bash is a project developed and promoted by GNU and is an extension of the Bourne shell. Bourne shell is the original shell used by UNIX, author Steven Bourne Bash is the

Use an automated shell script to find detailed thread information used by the CPU. After some interceptor code is added to the project, the CPU alarm shows that the CPU usage exceeds 100%; If you want to find out which code consumes too much