Shell

CopyCode The Code is as follows :#! /Bin/sh # Determining whether a file exists # Link: www.jb51.net # Date: 2013/2/28 Mypath = "/var/log/httpd /"Myfile = "/var/log/httpd/access. log" # Here, the-x parameter determines whether $ mypath exists

CopyCodeThe Code is as follows: #/bin/bash # History # Paste the following code directly to/etc/profile. User_ip = 'Who-u am I 2>/dev/null | awk '{print $ NF}' | sed-E's/[()] // g'' Histdir =/var/log/. hist If [-Z $ user_ip] Then User_ip =

Shell logical operators involve the following types. Therefore, you only need to make proper selection to solve many complicated judgments and get twice the result with half the effort.   I. logical operators       Logical

Previous We all know that Linux Shell is very powerful in text processing. There is a powerful set of text processing tools: grep, sed, awk. Grep is often used for searching and matching text and SEDCompositionThis edited replacement and awk are

Original article link While read wone wtwo wthreeDo[-Z $ wone] & continue # test whether the content of this row is emptyXxx = $ wone # extract contentDone Echo "$ XXX" # The variable obtains the content in the file. The following methods cannot

## Check the PID of such program#Checkpid (){If [-z "'ps X | grep $1 | grep-V grep | grep-V $0 | awk '{print $1}'' "]; thenEcho "the $1 program cant run well ."Fi}       Simple Description: PS reportProgramStatus. Ps x shows all programs,

1. Count the total number of rows of all common files in a directory # Practical scenarios: when designing a graduation project, you need to calculate your ownCodeNumber of rows # Solution 1:Find.-Type F-name"*. C"-Exec cat {}\; | grep-V'^ $'|

[Root @ localhost ~] # Echo $ {mail}/Var/spool/mail/root[Root @ localhost ~] # Echo $ {mail ###/*/} # pre-Greedy match DeletionRoot[Root @ localhost ~] # Echo $ {mail #/*/} # pre-match DeletionSpool/mail/root[Root @ localhost ~] # Echo $ {mail %/*} #

1. http://edsionte.com/techblog/archives/3712 echo and backslash Group records:2. This is only a variable. Double quotation marks will prevent shell tokens from echo "a B" and echo a B. 3 -------- 4 "a B" is a parameter of echo, while echo a B is

When it comes to shell wildcard (wildcard), it is often used. The following is an example: #1 [chengmo@localhost ~/shell]$ lsa.txt b.txt c.old#2 [chengmo@localhost ~/shell]$ ls *.txta.txt b.txt#3 [Chengmo @ localhost ~ /Shell] $ ls d *.

It may have been a long time to stay in the shell, so that the current world is almost confused.This is the case when developers are busy with development and do not know the changes in the environment around them all day long. Maybe in

The Shell script is mainly used to initialize the new Linux server system, including: Disable IPv6 ModuleDisable SELinuxShow vim colorsSet system language EncodingOptimize system servicesKernel Parameter optimization.It can be modified according to

Shell also has a real debugging mode. If an error occurs in the script "strangescript", you can debug it as follows: Sh-x strangescript This will execute the script and display the values of all variables. Shell also has a mode that only checks

Copy codeThe Code is as follows :#! /Bin/bash If [! -F/tmp/down_count]; then Echo "0" & gt;/tmp/down_count Fi Curl-I tomcat-host-o "/tmp/status" & gt;/dev/null 2 & gt; & amp; 1 Code = 'awk' NR = 1 {print $2} '/tmp/status' If ["$ [code]"-ge 500]

Copy codeThe Code is as follows: # include Using namespace std; Void ShellQin (int A [], int n) { Int gap = n/2; Int I, j; For (; gap> 0; gap = gap/2) // set the initial gap, group by gap, and decrease by gap/2 { // After the gap is set, insert and

This e-mail alert script is widely used. Many of the sendmail and postfix scripts are used, and some of them are used in perl's NET: SMTP and Authen: SASL modules, but I am not using perl well. I always send some inexplicable emails (such as if (a> 1

Copy codeThe Code is as follows :#! /Bin/sh # Obtain the date interval from the first day of the quarter to yesterday # Link: www.jb51.net # Date: 2013/2/28 Day = 'date-d "1 days ago" "+ % Y % m % d "';Year = 'expr substr $ {day} 1 4 ';Month =

1. Methods of raw violence Copy codeThe Code is as follows: myLinux:/home/zhanhailiang/public_html # killall nginx 2. gentle approachFind the pid of the specified process and kill | kill-USR1 Copy codeThe Code is as follows:

Bash shell supports only one-dimensional arrays, but there is no limit on the number of parameters. Declare an array:Declare-a array(In fact, you don't need to declare it. You just need to assign values to variables in the array mode. BASH knows

Copy codeThe Code is as follows :#! /Usr/bin/CT-f Set ipaddress [lindex $ argv 0] Set passwd [lindex $ argv 1] Set timeout 30 Spawn ssh root @ $ ipaddress # CT "yes/no" # Send "yesr" Reset CT "password :" Send "$ passwdr" CT "] *" Send