Shell

1. Create shell script file     Create file, add executable permission to file chmod +x file    format: Specify the shell        #! in the first line of the file /bin/bash    NOTES: #开头的命令 (except  #!/bin/bash  in the first line)     Display message:

#!/bin/sh### globalsimg_ext= "{png,jpg,gif}" sql_file= "My_images_mysql.sql" sql_ins= "INSERT INTO  images values  ("Sql_imageid_range=0sql_imagetype=1sql_name=" "sql_image=" "### ERRORNORMAL=0ERR_ Args=1err_no_dir=2err_no_file=3retval= $NORMAL #####

== : Two strings are equal! =: Two characters not equal> : Whether a string is greater than another string : Whether a string is less than another string- N String : Tests whether the specified string is empty- s string : Tests whether the

Use of arrays$array _var= (1 2 3)--use parentheses to define an array with a column value$echo ${array_var[0]}--The first element of an array$array _var[0]= "Zero"--defines an array using the form of an index and a value$echo ${array_var[@]}--Print

Condition test Type in Bash script: integer testString testFile testExpressions for conditional tests: [Expression][[expression]] expression must have a space before and after itinteger test :-eq: Tests whether two integers are equal and equal to

Shell scripting, there are three kinds of control structure are: sequential structure, conditional judgment structure, loop structure. This article summarizes the use of conditional judgment constructs in shell scripts.The structure of conditional

Shell scripts can also receive script parameters, like commands and applications, as they are executed .An application example:VI addhead.sh:Suaddhead ns=591 $Perform:./addhead.sh Rtm_step10_lap.dat rtm_step10_lap.su (where rtm_step10_lap.dat is

The test command in the shell is used to check if a condition is true, and it can be tested in three aspects of numeric, character, and file. Numerical test Parameters Description -eq Equals is True

Echo ' seq-s ' 10 '--command to use anti-quoteecho $ (seq-s "" 10)(())LetExprBC--Features support for fractional counting$[]----------[Email protected] ~]# ((ruan=1*8-9))[Email protected] ~]# echo $ruan-1---------[Email protected] ~]# b=$

(1) rsync (remote synchronize) is a data synchronization tool that allows you to quickly sync files between multiple hosts via Lan/wan, or use rsync to synchronize different directories on your local hard drive. (2) Rsync is a tool for replacing

This morning a friend suddenly QQ asked, shell programming function why return can only be an integer, how to return the execution of the function and save to a variable. In fact, this problem is very good to solve---only need to seriously

Shell Foundation-environment variable configuration fileSource configuration file or. Configuration file:After the environment variable is written to the configuration file, the user needs to re-login to take effect, but with the source command, it

One: Linux shell string interception and splicingSuppose there is a variable var=http://www.linuxidc.com/123.htm 1 # Intercept, delete the left character, and leave the right character.  Echo ${var#*//}where Var is the variable name and the # is an

1. First, log on to the remote Linux server, such as 192.168.127.222, with the normal password login method;2. Click the Key Generation Wizard in the tool:650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/74/67/wKioL1YcmyPy22e-AAI3RPggo2A573

Transfer from http://www.cnblogs.com/dwdxdy/archive/2012/07/25/2608816.htmlThe style files are often processed on a line-by-row basis, how to get each row of data in the shell, then process the row data, and finally read the next row of data, loop

Linux Login Server Knock command too much, at some point it is inconvenient, so the shell wrote aI. Description Supports both secret and key formats The user name and password are both written and saved in clear text Two. Configuration

FunctionFunctions have the same functionality:Simply put, the function of the program is to call the same part of the code in a number of parts, and then a name, so the function is called the name can be, in the modification of the code, only need

                          Bash of the Base Infrastructure Special Sex21. provides a programming environment Program: Instruction + data program programming Style: Process: command-centric, data-serving instruction; Object type: Data-centric,

1.shell OverviewThe shell is a command-line interpreter that provides the user with an interface system-level program that sends a request to the Linux kernel to run the program, and the user can start with the shell, suspend, stop, or even write

This article is intended to review the definition and assignment of arrays in shell script programming, to read arrays, and to get the length of an arrayKnowledge Reserve Array : Multiple contiguous separate memory spaces, each memory