Shell

Shell is a command interpreter. It is an insulation layer between the operating system kernel and the user. To be precise, it is alsoA powerful computer language. A shellProgramIt is called a script and is a very easy-to-use tool.Combine system

Shell is an interactive command interpreter. Shell is independent of the operating system. This design allows you to flexibly choose the appropriate shell. Shell You can type a command in the command line,After being explained by shell, it is

The $ symbol in Bash is used to replace the parameter name with the value represented by the parameter. For $, braces are optional, that is, $ A and $ {A} represent the same parameter. $ {} There are several expressions with colons: $

Shell script debugging-run log 1   This article mainly describes how to output debug logs in shell scripts.   C/C ++ debug log In C/C ++, _ file __, _ FUNC __, _ line _ indicates which log of the current row comes fromSource codeWhich

Shell scripting is an interpreted language; The essence of shell scripts is an ordered set of shell commands; 1. Basic shell programming process 1) create a shell file 2) grant executable permissions to chmod A + x filename 3) execute the shell file.

Chapter 2: handling user input Command Line ParametersRead ParametersBASH Shell assigns some special variables called positional parameter to all the parameters entered by the command line.Even include the program name$0: Program name (Absolute

Chapter 2: using structured commands Use the if-then statement if commandthen commandsfi If the exit status code of the command after if is 0, execute then. Another Form if command; then commandsfi   If-then-else statement if commandthen

Shell sorting is a form of change in insert sorting. Because insert sorting compares each element and compares the current element with all the previous elements, in the worst case. Therefore, DL. shell proposed shell sorting in 1959, that is,

  Some terminal shortcut keys: CTRL + F Forward one character CTRL + B Move one character behind CTRL + E Move to end of line CTRL + L Clear Screen CTRL + d Delete current

1. condition test Two formats: test condition or [condition] (Note that spaces are added on both sides)Condition can be a logical operation of multiple sub-conditions. The logical operator numbers include: -A logic and -O logic or ! Logic No &, | 2.

I don't know when I wrote something, But I was found by archaeology when I sorted out the documents. I just smiled at those people who were bored. If the errors in this article cause all mental losses to you, contact the insurance company! Of course

 FindSearch for files or directories. Syntax: Find [directory...] [-Amin ] [-anewer ] [-atime ] [-Cmin ] [-cnewer ] [-ctime ] [-daystart] [-depyh] [-empty] [-exec ] [-false] [-FLS ] [-follow] [-fprint ] [-fprint0 ] [-fprintf ] [-fstype ] [-gid ]

Shell script Learning (1): Shell variables and some common commands Shell allows you to create variables to store data, but does not support basic data type variables (such as int, float .....), shell interprets any value assigned to a

Iv. Loop Structure statements Common shell loop statements include for loop, while loop, and until loop. ForLoop Syntax: for variable in list Do Operation Done Note: The variable is used inside the loop to refer to the object in the List currently

@ Rigorous use of set @ Set-eux -E. If the command returns a non-zero value, exit immediately. -U when the execution parameter is included, the unset variable is used as the error handling (if the extension attempt appears in the unset variable, the

Is there the same command as NBTSTAT in Linux! View other information through IP: Host Name, Mac, etc. You can use nmblookup-a ip address. You can also use nbtscan. ARP command: ARP iPad. Local or ARP 192.168.1.108 or ARP-A or ARP VI search string:

Shell script used to detect Processes 10:38:08 | category: centos | font size subscription Script 1: #! /Bin/sh Program = XXXX # process name Sn = 'ps-Ef | grep $ program | grep-V grep | awk '{print $2} ''# obtain the process port numberIf ["$ {sn}"

#! /Bin/sh # Filename: 2.sh B = 9 E = 15 Tmpb = $ B While [$ tmpb-Le $ E] Do Echo $ tmpb # Tmpb = 'expr $ tmpb + 1' // OK Tmpb = $ (expr $ tmpb + 1) Done After the script is executed, the output result is: 9101112131415   Note: The

To determine whether the variables in a script are empty, I wrote a shell script like this: #! /Bin/sh # Filename: Test. Sh Para1 = If [! -N $ para1]; then Echo "is null" Else Echo "not null" Fi Then run the Script: test. sh uses

Linux system resource load is too high and Apache shell script is automatically restarted   When we routinely maintain Apache Web servers in Linux, the endless loop caused by crawler crawling cannot jump out, or the collection of data from peers