shell scripting practice programs

Tags: file src print delete a lot. BASHRC Child shell ALT hintMany programs and scripts use environment variables to obtain system information, store temporary data, and configure information.6.1 What is an environment variable:Bash Shell uses a feature called environment variable (environment variable) to store information about

Try to make your work more efficient, write scripts, and use scripts, often with less effort. So, take some time today to learn about shell scripting.--------------ahead of the high-energy warning, this article is written slightly entertain, if you have to look uncomfortable, please go to the top right corner----------------------The shell has two ways of executi

First, using the For loop structureTarget:This case requires writing a shell script chkhosts.sh that uses a for loop to detect the surviving status of multiple hosts, with the following requirements and instructions:1> Ping Detection of 192.168.4.0/24 network segments2> Ping Detection can refer to the pinghost.sh script of the preceding dayThe 3> script can traverse the ping hosts and feed back the surviving statusAfter the test script is executed, th

Bash shell scripting Getting Started (iii) cycleWhat is loop execution?To run a code segment repeatedly multiple timesHow many times to run repeatedly:Number of cycles known beforehandNumber of cycles unknown beforehandThere are entry conditions and exit conditionsRelated commands: For, while, Until,selet,Use for commandRole:Assigns the element in the list to the "variable name" in turn; The loop body is ex

Many people may have thought about using PHP to write some programs such as timed sending, but they have no way to implement PHP on a regular basis. This article was invented once when I went to PHPBuilder, so I want to translate it for you (and make some corrections at the same time). I hope many people may have thought about using PHP to write some programs such as regular sending, but they have no measur

Shell Getting Started Tutorial (1)-shell-JUSTKK's Column-Blog channel-csdn.nethttp://blog.csdn.net/justkk/article/details/43795131 Shell Getting Started Tutorial (2)-Variables and Parameters-JUSTKK-Blog channel-csdn.nethttp://blog.csdn.net/justkk/article/details/44081993 Shell Getting Started Tutorial (3)-command edito

Some good habits of shell scripting 1. Naming rules The script name ends with. SH, and names are as famous as possible. Here are a few of the script naming styles that are available for reference. Through the following fresh and refined style, readers can easily understand the role of the script.clearlog.sh clearlog.sh clearsql.sh snmp_install.sh monitor.sh 2.

overwrite, the original number of filesAccording to LostC: Append the standard output to the file with >> attached to the program >> files to the endD: Piping "|", PROGRAM1 | Program2 the standard output of the PROGRAM1 as a standard input for PROGRAM2More than two programs can be linked together, but also greatly improve the speed of implementationEg:tr-d ' \ r ' Output to a file in the final sequence.(12) Special documents/DEV/NULL and/dev/tty 46Th

Basics of Linux Shell scripting here we first talk about the shell of the basic syntax, the beginning, comments, variables and environment variables, to do a basic introduction, although not related to specific things, but lay the foundation is to learn easily after the premise. 1. Linux Scripting Basics Basic Introduc

The article is for personal opinion, please correct me. Before we introduce the shell script, let's begin by understanding some basic concepts. What is a program? Process? The program is a set of instructions plus data, the following diagram can clearly see the concept of the program The program itself is static and can only become dynamic when it is executed by the CPU. However, the CPU execution speed is very fast, one execution o

What is a shell script sampleLet's look at an example:#!/bin/shcd ~mkdir Shell_tutcd shell_tutfor (i=0; iExample explanation Line 1th: Specify the script interpreter, here is the interpreter with/bin/sh Line 2nd: Switch to the current user's home directory Line 3rd: Create a directory Shell_tut Line 4th: Switch to the Shell_tut directory Line 5th: Cycle conditions, 10 cycles Line 6th: Create a test_1 ... 10.txt file Li

Tags: ges vim editor nginx root user Form bash script expec Ash rsyncObjectiveLearn about the knowledge reserves required for Shell script programming:Vi/vim Editor Command VIMRC set to be proficientBasic commands, more than 100 skilledBasic and common Network Service commands to be: NFS, rsync, INotify, Lanmp, Sersync, SSH keyI. Shell scripting concepts and exam

backupdrwxr-xr-x 2 root root 4096 10:29 confdrwx------ 2 root root 16384 24 16 : Lost+founddrwxr-xr-x 4 root root 4096 10:29 mysqldrwxr-xr-x 8 root root 4096 Oct 8 13:09 so Ftwaredrwxr-xr-x 2 root root 4096 10:41 tmptotal 233600drwxr-xr-x 9 root root 4096 Nov A Pache-tomcat-1drwxr-xr-x 9 root root 4096 Nov apache-tomcat-2drwxr-xr-x 9 root root 4096 22 08: Apache-tomcat-rentaldrwxr-xr-x 3 root root 4096 Jan 8 codedrwxr-xr-x 8 UUCP 143 4096 Nov java-rw-r--

The experience of Shell scripting in developmentThis period of time in the development of a program, program output has a lot of logs. Sometimes you need to log to analyze the problem of the error. Separate viewing efficiency is too low to analyze anything. So I thought of the shell. Log files are on Android's phone!Development environment Fedora, MacOS.Mobile ph

overwritten.Syntax for input redirection: directives Example: For example, we have a file Test.txt with 3 lines of content. We want to count his number of rows, which can be counted by executing commands: Wc-l Result output: 3Well, through the content of section four, we have mastered the basic use of the shell, can write some simple shell program, but there is a gap between the real coding, so we have to

command. You can use Echo to print any variable value in any place where you suspect it is wrong. That's why most shell programmers spend 80% of their time debugging programs. of the Shell programThe advantage is that there is no need to recompile, and it does not take much time to insert an echo command.The shell als

-centric, instantiating data into classes, and deploying directives around the needs of dataClasses, properties, methodsLow-level language:AssemblyShell script ProgrammingAn over-programming language that interprets runs, relies on external program files to run;What exactly is a shell script?1. Plain text Document--the data stored in the file is stored in characters;2. The combination of a large number of commands to solve user problems according to t

'Cat"${timepoint}. Log"| Awk-f' \ t ' ' {if ($8 = = 579) {print substr ($, index ($, "UID") + 5, +)} '| Sort-rn | Uniq-c |sort Cat -- +. log | Awk-f' \ t ' ' {if ($8 ~/^4/) {print $8, substr ($, index ($, "UID") + 5, +)} '| Awk' {if (= = = 404) {a[$2] +=1} else if ($ = =) {b[$2 +=1]} else{}} end{for (i in a) print A[i] "==>" I; for (I I n b) Print b[i] "==>" i} ';;Esac}if[$# -ne 3]; ThenEcho "Usage: $ 519 2014-12-28 11-29";Exit 1;fiGotologfile $ $ $Code