Shell

If you manage a large number of sites and servers, it is quite painful to modify the configuration file every time. So I thought of using shell scripts to generate bulk configuration files and configuration data. The following script is a shell

1. Write the shell script, calculate 1-100 's and;#!/bin/bashsum=0;for((i=0;i100$sum$i ))}echo$sum2) Write the shell script, ask to enter a number, and then calculate from 1 to the input number and, if the input number is less than 1, then re-enter

Source:http://zhidao.baidu.com/question/322131711.htmlFile comparison Operators-e filename true if filename exists [-e/var/log/syslog]-D filename True if filename is a directory [-d/tmp/mydir]-F filename True if filename is a regular file

.: Denotes any character*: Matches the previous character, A * indicates: 0 or more A+: Matches the preceding character to represent 1 or more preceding characters?: matches the preceding character to represent 0 or more preceding characters#！

1.history Save History Command 1000, history-c empty;2.! String calls the most recently used command,! Vim's most recently used vim,! N calls the last Ming ' l,!242 that begins with N to invoke the No. 242 command in history.3.alias Rename, alias h5=

Tag: IP address #!/bin/bash#author: #date: 2015-6-13#filename:ip.sh############################ #ifconfig_cmd = ' which  Ifconfig ' $ifconfig _cmd > ifconfig.me################################## #function  obtain_ip_ Information () { if grep -q  '

[Condition 1-a Condition 2] When 1 and 2 are true [condition 1-o condition 2] when 1 and 2 one is true [! condition] Take counter && and | | 　　Or! unsigned [-D name] && Echo ' is dir ' is true when the name is directory, then the input has the

1. Value Format: Test "NUM1" OPR "num2" ["Num1" OPR "num2"] OPR Value: Equality:-EQ Unequal:-ne

path=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/mysql/binexport  Java_home=/usr/java  export classpath=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar   export path= $PATH: $JAVA

Sometimes a shell script is written to execute a sequence of programs. Some programs do not exit immediately after they are stopped, such as a tomcat hanging, even if the kill-9 command is not instantaneous.So if the shell does not wait for it to

1.Cut: Command Select cut-d ' delimited character '-F fields-D: followed by delimited characters, used with-f-F: Cutting a piece of information into several segments according to the delimited character of-D-C: Remove a fixed character range in

awk command# awk ' Condition 1{action 1} Condition 2{action 2} .... ' FilenameGeneral use of relational expressions as criteriaAction: 1, formatted output 2, Flow control statement column that handles the cut command cannot intercept spacesExample:

basic regular expression metacharacters role * matches the previous character 0 or more times . match any character except newline

Shell Script (v)4. Sed and awk(1) SEDA, common parameters#文件编辑工具, text files and standard input can be edited, the standard input is keyboard input,#文件重定向, string, variable, and pipe text.#-n: Do not print all rows to standard output;-e: Resolves

$ who can know how many landings on the system$who |wc-l count the number of usersNote: | is a pipe symbol that can be used to establish a pipeline between two programs (pipeline): The WHO output, a WC input, the result of the WC is the number of

Http://c.biancheng.net/cpp/view/6998.htmlOpen a text editor, create a new file, the extension sh (sh for Shell), the extension does not affect the execution of the script, see the name is good, if you write a shell script in PHP, the extension is

The various operating meanings of the shell in this, can refer to my three years ago this

More field servers, password 3 months expired, at the expiry of the need to change the password.Write with expect, try to log in 2 times after the exit (Prevent password error when the account lockout), time-out retry.The shell script calls and

SHELL script-1, shell-1 .: Represents any character *: Matches the preceding character. a * Indicates zero or multiple. +: Match with the previous character to indicate one or more previous characters. ? : Matches with the previous character to

Shell script to delete the folder N days ago ----- the difference between the date command on linux and mac Background:Every day you build things and put them in different folders by date. For example, today's construction is put in, tomorrow's will