shell programming

#!/bin/bash. Hellofunset"now going to thefuction Hello" hello# here will output the message:. /"back from thefunction Hello"6.6. function return Status valueExample 1:#!/bin/bashfunction Hello () { "Hello, today is ' date '" return 0 now going to thefunction Hellohello# next to output the return status value, with $? represents echo $? "back from thefunction Hello"Example 2: #!/bin/bashfunction Hello () {echo hello, today is ' date ' " return 0 }echo " now going to the functio

Redirection, environment variables, and Shell functions of advanced shell script Programming Shell is not limited to simply executing commands line by line. One of the more powerful functions is the ability to create functions and function libraries. You want to customize the command line interaction mode or automate

Linux System-shell programming-several shell scriptsone kill the userkilluser.sh#!/bin/sh# The script to kill login userUser_name= "$"/bin/ps aux | /bin/grep $user _name | /bin/awk ' {print $} ' >/tmp/temp.pidKill_id= ' Cat/tmp/temp.pid 'For PID in kill_iddo/bin/kill-9 $PID 2>/dev/nullDonetwo adding users in bulkuseradd.sh#/bin/shecho "Input name"Read nameecho "

Reference book "VC + + Windows Shell Programming" Here is just a record of the resource, recommended to the connection listed below for viewing with VC + + for Windows shell extension compiled by CCC compiler preamble: Seen Some extensions to the Windows shell, which generally use the Windows

The knowledge points in this article are related to conditional testing of shell scripts.Often in shell scripts we need to do a variety of conditional judgments, such as testing whether a file exists, whether it is a file or directory, whetherhas execute permissions and so on, so in a shell script, conditional judgment is still critical. Next we get to the point:

redirected file descriptor number in front of the load > operator. Because the file descriptor for the standard error output is 2, use the 2> operator. This method is useful when you need to discard the error message and prevent it from appearing on the screen.PipelineYou can use the pipe operator | To connect to a process, unlike MS-DOS, where the process of connecting through a pipeline can run at the same time, and can be reconciled automatically as the data flow passes between them. For exa

http://blog.51cto.com/zt/267 Original works, allow reprint, please be sure to use hyperlinks in the form of the original source of the article, author information and this statement. Otherwise, the legal liability will be investigated. http://johnwang.blog.51cto.com/474770/326073 Shell Introduction The shell is in the outer layer of the kernel, which is responsible for receiving commands entered by the user

First shell script--helloworld[Email protected] ~]# VI sh01.sh#!/bin/bash #! Indicates which shell# this is my first shell script #注释部分echo-E "Hello world!" Exit 0[[email protected]~]# SH sh01.sh # execute SH file Hello world! using bash or SH commandSecond shell script--Receives user input from the terminal into the

Turn from: The world of the Intelligence ReporterThis article combines a number of examples to illustrate how to write a shell script.Why Shell ProgrammingIn Linux systems, although there are a variety of graphical interface tools, sell is still a very flexible tool. The shell is not just a collection of commands, but also a great

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 look at the usage of the conditional statement if, and use this simple syntax to illustrate what the shell script does

"ExitProcess" 2hold1=/tmp/hold1.$ $HOLD 2=/tmp/hold2.$ $function exitprocess () { echo-e "\ Nrecived Interrupt .... " echo-n" Do you really wish to exit? ( y/n) " read ANS case $ANS in y|y) rm_tmp_file ;; N|n) ;; *) exitprocess ;; Esac}function Rm_tmp_file () { echo "2.4.evalBrief introductionThe eval command will first scan the command line for all permutations before executing the command. This command applies to variables that sca

Variable assignment Variable access Variable input 4.1 variable assignment In shell programming, all variable names are composed of strings and do not need to be declared. To assign a value to a variable, the format is as follows: Variable name = Value Note: No space before and after equal sign (=) For example: X = 6 A = "how are you" Assign the value of 6 to variable X, and assign the value of

This article is in the study of "with the old boy learning Linux Koriyuki Shell Programming Practical" the knowledge points recorded in this book. I have benefited greatly from reading this book, but this is only my personal opinion. Now let's get to the bottom of the shell script.The shell itself is a command interpre

Shell programming: before running shell script tracing and debug scripts, the most feared problem is the syntax error! So how can we debug it? Is there a way to determine whether there is a problem without directly running the scripts? Haha! Of course! Let's take the bash-related parameters for determination! C code [root @ www ~] # Sh [-nvx] scripts. sh option a

Location parameters Internal Parameters Just as the LS command can accept directories and other parameters as its parameters, parameters can also be used in shell programming. Parameters in Shell programs include location parameters and internal parameters.3.1 Location Parameters The parameter provided by the system is calledLocation parameters. The value of th

, if different, the group logical operation result is true, if the same, then the result of the logical operation is FalseShell script Programming:What is programming: Writing Program source codeIn order to enable users to use the computer, you can let the computer to do some tasks in a fee-interactive way, you need to make these tasks into a file, so that the computer sequential acquisition, so as to complete the taskProgramming Languages:Advanced La

This article is also the second of the book note in Chapter 4 Basic shell programming of learning the bash shell 3rd edition, but we will not limit it to this. String operation In the following description, ":" Can be deleted. "Yes" means "exist but cannot be null". ":" means "exist ", this parameter can be left blank: $ { Varname :- Word } : If varname exists

the last deletion Ctrl+d: Deletes the letter where the cursor is located; Note the difference between backspace and ctrl+h, these 2 are the characters before the cursor is deleted CTRL+F: The cursor moves right Ctrl+z: Move the current process to the background and use the ' FG ' command to recover. Like Top-d1 and then ctrl+z, to the backstage, then FG, and back ESC Combination Esc+d: Delete A word after the cursor Esc+f: Jump Right One word Esc+b: Jump to the left one word Esc+t: Two

4. Several examples of common shell scripts4.0. When writing scripts (also for programming), it is best to write well-developed annotations4.1.kill_processes.sh (a script that kills the process)#!/bin/bashcurrent_pid=$ $ps-aux | grep "/USR/SBIN/HTTPD" | Grep-v "grep" | awk ' {print $} ' >/tmp/${current_pid}.txtfor PID in ' cat/tmp/${current_pid}.txt ' do{ echo "kill-9 $pid" Kill -9 $pid}9donerm-f/tmp

Tags: file external shell Script programming intermediate run Info GPO Language POS1. Like other languages, the shell can also contain external scripts, which makes it easy to encapsulate some common code as a standalone fileExample: The testshellfileinclude.sh script is as follows:the #!/bin/Bash#shell file contains t