Shell

First, awk uses ordinary variables in the shell Method 1: Use the quotation mark method Aa= "Hello" awk ' BEGIN {print ' $aa '} ' Output $AA awk ' BEGIN {print ' $aa '} ' Output Hello awk ' BEGIN {print ' ' $aa '} ' Output empty Aa= "hello!

If the file is a. css file or a. js file, it is processed. File=$1 if ["${file##*.}" x = "css" x]| | ["${file##*.}" x = "JS" x];then Do something Fi Attention: 1> extract file suffix name: ${file##*.} # #是贪婪操作符, matching from left to right,

Problem description A few days ago, a friend needs real-time monitoring of a Linux system under a process, when the program is running to continue to monitor, when the program is finished to the end of a word to the end, and do follow-up. Problem

Source: Public StaticString CreateFile () {String cmd ="Echo\"Hhahah\"> F:\\AAA\\Azzz.txt "; File File =NewFile ("C:\\Windows\\System32 "); StringBuilder result =NewStringBuilder ();Try{//execute the specified string command in a separate process

LINUX SHELL parsing JSON format 1. Use tool JQ https://stedolan.github.io/jq/ Download version Linux version Jq-linux64 Ubuntu Direct sudo apt-get install JQ can be. 2. Parse JSON [Root@cas script]# cat Test.json {"Tasks": [{"id":

I wrote a Java program with the main method entry, already packed a jar and already started running under UNIX, but I wanted to write a script file to make it easier for managers to start and shut down my Java process. Similar to Tomcat

When executing a pre-existing shell script file under a Linux system, it prompts you that the file does not exist. The general reason for this is that your shell script is written in a system that is inconsistent with your execution script, such as

Unlike Java, PHP and other languages, the process control of SH is not NULL, such as: public class test{public static void Main (string[] args) { int a = ten; if (a > 5) { System.out.println ("A is greater than 5");

Redirect Method When the shell sees #!/bin/bash GDB Help Quit Eof Pipe mode The combination of the Echo, Sleep command, and pipe operator (|). #!/bin/bash (Echo ' root '; sleep 1; Echo ' root ') | passwd Modify the root user's

#!/bin/sh #backup tomcat1 log lastdate= ' date-d "-7 Day" +%y-%m-%d "logfile=/tomcatlog/localhost_access_log.$ Lastdate.txt if [-F "$logfile"]; Then echo ' exist file ' mv $logfile/tomcatlog/localhost_access_log. $lastdate. Txt.bak Tar

One, the read command reads the file automatically removes the space before and after the line. A.txt: (There are spaces before and after each line) 11111 222222 3333333 A.sh: #!/bin/bash While Read Oneline;do echo "$oneline" Done Execution

The filter condition for the scan command in the Hbase Shell Prefixfilter is to filter the Rowkey. The difference between scan and get is that get gets the data from a row, and scan gets the data from several row, so you can set the filter

In shell scripts, the variables are global by default. So recursive calls require the local keyword to be used to display identity locals so that recursive calls to functions can be implemented. Wrote a recursive calculation of factorial script,

Impala-shell Import and Export Parameter description: -q Query (--query=query) executes queries from the command line without entering Impala-shell -d default_db (--database=default_db) Specify database -b (--delimited) to format the

HBase provides users with a very convenient way to use it, which we call "HBase Shell."The HBase shell provides most hbase commands, which can be easily created, deleted, and modified by HBase shell users, as well as adding data to tables, listing

#!/bin/shA=1 a=$ (($a + 1)) a=$[$a +1] A= ' expr $a + 1 ' Let a++ Let A+=1 ((a++)) Echo $a 1. Classical methodsLength= ' expr length + 1 '2. Bash only$ ((length++)) 1. i= ' expr $i + 1 ';2. Let i+=1;3. ((i++));4. i=$[$i +1];5. i=$ (($i + 1))

Listen to people say that text classification when processing 100G text files, incredibly without big data, processing method is to use the shell split to split into a number of small files. Split command NAME split-split a file into pieces

测试操作符 Common Test Operators English name Description -F file file files exist and are normal files True, that is, test expressions are set -d file Direct Ory

#!/bin/bashsrc_path=/data/www/logsdst_path=/data/www/logs_bakfor rfile in ' Find $SRC _path/-depth-maxdepth 1-type F | Awk-f '/' {print $NF} ' DOTAR-ZCPVF $Dst _path/$rfile. tar.gz $Src _path/$rfiledonefor dir in ' Find $SRC _path/*-type D|awk -F '/

Most basic: Remember the previous:#!/bin/bash, and the file suffix name is generally. shVI HelloWorld. SH #!/bin/bashecho"helloworld"Then remember to add permissions to the script, because the default is read and write permissions, default to all