Shell

The shell sorting algorithm was first proposed by the D.L shell in 1959, assuming that the elements to be sorted have n, then each insertion sort is not the same as the elements, but goes to an interval. The shell first sets the interval to N/2,

Function:1. Only in the backup machine, the remote server only need to allow the backup machine with root through the key login;2. Configure which servers to back up on the backup machine, add or subtract the array in need_backup_servers;3.

This email alert script is everywhere, a lot of use of sendmail, Postfix, feel a bit overqualified, and some use Perl net::smtp and AUTHEN::SASL module, but I use Perl is not good, The old send out some baffling mails (for example if (a>1) {print (a)

The generated password and user input can accept duplicate numbers.So the relative general rule of guessing numbers may be much more difficult. This version of the rule: a--numbers are right, position is right.b--excludes the result of a, the

1, the shell variable statement judgment An expression meaning ${var} Variable var with the same value as $var ${var-default} If Var is not declared, then use $default as

Sometimes we need to delete the empty folder recursively, search the internet for a while, did not find a better shell script, so we wrote a Script Copy Code code as follows: #!/bin/bash # Author: Ten years later, Lou's brother #

Copy Code code as follows: [Root@web-server php]#/etc/init.d/httpd Restart Shell-init:error Retrieving current Directory:getcwd:cannot access parent directories:no such file or directory This error indicates that the GETCWD command could

The shell can represent different data in the system without invoking the 3rd party command. The following presentation method is summarized here. The default value of the shell script is handled by the 10 number, unless the number has a special

Copy Code code as follows: #/bin/bash # Creator:lihuibin # date:2014-03-10 16:45 # Desc:upload file to FTP Hosts= "192.168.56.100" Port=21 User=test Pass=testpwd Work_path= "/var/www/cms" Packname= "Publish" #hosts =$1 #port =$2

I am not studying things under Linux, so here is only a description of the use of shell script, I am in the process of using the problem recorded, but also write down some of the rules of the shell script syntax, easy to view later. Let's take a

Basic knowledge of strings Strings are the most commonly used data types in shell programming (except numbers and strings, and nothing else works), strings can be in single quotes, double quotes, or without quotes. The difference between single and

Usually in the CentOS, Rhel OS, we mostly through the chkconfig to manage services, such as the boot automatic service.Here to introduce a very useful nginx startup script. and simple to use, as follows: 1. Execute the following order:

Example one: Drawing special graphics Copy Code code as follows: #!/bin/bash Max_no=0 Echo-n "Enter number between (5 to 9):" Read Max_no if! [$MAX _no-ge 5-a $MAX _no-le 9]; Then echo "WTF ... I ask to enter number

In addition to the "If,else" form, there are other forms of "if" statements: Copy Code code as follows: if [condition] Then Action Fi The statement performs an action only if condition is true, otherwise the operation

First set up a file, very messy, no rule: A positive sort: Inverted sort: Uniq Delete duplicate rows in a file: Use this command to sort the files first. For file redundancy, as long as all duplicate characters of the file are displayed

0. IntroductionEncountered in real-world application development: Storing unformatted file data in a database. For traditional formatted data: Ini/json/xml We all have a ready-made class library to implement. What about non-formatted data like this?

1. Structure　　2. Case studies#!/bin/bashecho "Wayne:input 1" echo "echo : Input 2" echo "We : Input 3" read-t 30-p "Input your choice:" Choca Se "$cho" in "1") echo "Wayne Love echo" ;; " 2 ")

Original: http://apps.hi.baidu.com/share/detail/31263915In the shell, the comparison between the string and the numerical method is different, pay attention to distinguishInteger comparison:-eq equals, such as: if ["$a"-eq "$b"]-ne not equal to,

Any partition used to 90% send a message to the specified recipient, to 95% on the subject of the message Warning (warning), instructions to send mail program email#!/bin/bash#Updated: 2008-03-03 PM by:leif ([email

The problem arises because the current release is used by executing scripts, all of which are mvn packaged, while execution causes problems.The solution checks, locks 、、、 before the script executes#!/bin/bash{flock -n 3 if [ $? -eq 1 ]then    echo