Shell

[Author]: KwuBased on the Sparksql call shell script run Sql,sparksql provides an option similar to-e,-F,-I in Hive1. Timed Call Script#!/bin/sh # Upload logs to HDFs yesterday= ' date--date= ' 1 days ago ' +%y%m%d

Script execution1. Give execution permission to run directlychmod 755 hello.sh./hello.sh #需要使用文件的绝对路径或相对路径2. Execute script via bash callEcho Output commandSyntax: Echo [-e] [output CONTENT]-E: Character conversions that support backslash controlEG1:

One, branch control statements1. If: Fi conditionif condition; ThenActionFi2. If: else.. Fi conditionIf Condition;thenActionElseActionFi3. If: else if: else.. Fi conditionIf Condition;thenActionelse if Condition;thenActionElseActionFiNote: If and

The TR command is used to replace the contents of the standard input. For example# echo ' HELLO World!!! ' | TR "A-Z" "A-Z"Hello World!!!Here the "A-Z", "A-Z" all represent the collection, the shell script defines the collection type is very simple,

Defining functionsfunction fname (){statements;}OrFName (){statements;}Pass parameters to the function:fname arg1 arg2;Exfunction parameter definition:FName (){echo $, $;echo "[email protected]";echo "$*";return 0;}Detect whether the command

Problem: Now there are two scripts, I want to match the contents of File1 by File2[email protected] home]# cat file13-1-1 potv=1,pota=0,potp=21-4-76 potv=1,pota=0,potp=12-1-2 potv=1,pota=1,potp= 13-1-4 potv=1,pota=1,potp=24-1-5 potv=1,pota=1,potp=27-

sudo equivalent to root permission execution commandGive executable permissions to all user files: chmod a+x script.shExecute script:./script.sh#./represents the current directoryCommand 1:echo "Welcome to Bash"Command 2:printf "Hello

[Email protected] ~]# history # View command history, command history exists in ~/.bash_history file ~]# !! # Indicates the execution of the previous command ~]# ls!$ # represents the last parameter of the previous command ~]#!950

You want to use a shell script to convert all the images in a folder to a pixel.Here are some of the wrong places:1. When defining a variable, the variable name does not add a dollar sign ($), such as:　　VariableName="value" Note that there can be no

This could be a disk detection error, especially after an unsecured shutdown or a damaged disk.Workaround:1. When selecting the startup item, select the first item, such as:Ubuntu 8.04kernl.2.6.22-16-generic2, press E to enter the editing state, in

Getting Started with Shell programmingOne, variable assignment and arithmetic operationDemo Sample code:A=1echo $alet b= $a +1echo $bc =$[a+b]echo $cd =$[c*2]echo $dlet e=d*2echo $ef =$[e%5]echo $fNote the "=" number must not have spaces on either

Several possible causes:1 The user's home directory belongs to a group that has been renamed Root, and the solution uses root to perform Cd/home/;chown username:username username2 The user's home directory was modified, this time if you want to

Guide In Linux, shell commands are efficient at running concurrent processing tasks, and shell scripts are not tedious, not only for the magic sound but also for the shell's color display. Now we'll use the color in the shell to improve the

First, what is the shellThe shell typically represents two levels of meaning, one is the command interpreter, such as bash, and the other is the shell script. In this section we stand on the command interpreter's point of view to illustrate the

Shell BasicsFirst, the variables in bash1, the definition of the variable: The variable is the memory unit of the computer, where the stored value can be changed.2, the variable's setting rule: The variable name cannot begin with the number, the

&&,| |, () application of the five symbols of,{},&When a shell script executes a command, it sometimes depends on whether the previous command succeeded. and && | | is used to determine the effect of the previous command execution.1 &&How to use:

Today, when you run the If judgment in the script, you always get into the corresponding branch and check the regular expression without errors. In the shell alone to execute or show no match. Rather strange, it was searched, it was found in the =~

This article ljh2000Author Blog: http://www.cnblogs.com/ljh2000-jump/Reprint please specify the source, infringement must investigate, retain the final interpretation right!Title Link: HDU5730Positive solution: divide and Cure $fft$Problem Solving

Method: Kill–9 ' pgrep Java ' Use the above command to kill all Java processes running on the server at once. Extension: The role of child shells and anti-application in shell scriptsLet's look at an example of a child shell:# Cat

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