shell scripting practice programs

output from the shell is directed to the standard output.Output redirection (>) can also be used to change outputs. The output redirection symbol allows you to redirect output that would otherwise be displayed on the monitor to the specified file.>> represents appending to a fileNote: With output redirection, the shell does not redirect error messages to the output redirection file. The error message will

Tags: shell scriptOne, Shell scriptScript: Can execute the file, after running can implement some function (command stack, non-interactive)Standardize the general composition of shell scripts#! Environmental Statement (Sha-bang)# comment TextExecutable codeSecond, simply write a shell script, according to international

Getting Started with Shell scripting--NextThis article introduces the following: Logical operators (, | 、!、 ^), test commands, script execution procedures1. Logical operators(1) and short circuit andTrue, False1 0And:1 1 = 11 0 = 00 1 = 00 0 = 0For , if the left condition is false, the value of the right condition is also evaluated. Features as long as a false is assumed to be falseShort Circuit with:

0. IntroductionPrepare to open a new pit and update a shell practice every day. Because shell scripts belong to the kind of skills that are unfamiliar or even forgotten when you're not practicing, I can only keep on practicing in order to resist the drag of forgetting.1. First day Practice topicsTopicPlease generate a

: Traverse: For ip_t in ${servers[*]};d o If ["$" = "$ip _t"];then is_ip_correct=true break FidoneCall other programs: Use ', and get the output result: ps3= "Please choose a branch:" Select Branch in' svn list svn://;d o if [$branch];then svn_dir= "svn:// using $ (), and obtain the output result: today=$ (Date+%y-%m-%d/%h:%m:%s)svn_version=$(SVN info $SVN _dir | grep "Last Changed Rev:" | awk ' {print $4} ')

Engine, you must modify the registry data of the Windows Script Engine component for the Microsoft Visual Basic Scripting Edition (VBScript) file. ChangeHkey_classes_root/vbsfile/Shell/Open/commandAnd set% 1Add to value% 11%/wscript.exe, SuchFigure 1. Figure 1. Change Windows Registry Value of the script engine component After creating key3, you can log on to the user account again and view the new

Overview:Overview:This section describes the array of shell scripting in Linux, advanced string processing, advanced variables, and configuring the user's environment.One, function and positional parameter extension1. TheShift command implements the jump in the position parameter, which squeezes the leftmost parameter650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M01/86/5B/wKiom1e9EFvAun-AAABG0xL4ac

1. Write more comments in the script This is a recommended practice that can be applied not only in shell scripts, but also in all other types of programming. commenting in a script can help you or others to read your script Learn about the different parts of the script. Comments are defined with a # number.2. when the script exits when the run fails Sometimes, even if some commands fail, bash may c

and so on one by one corresponds; case $MENU In Jiaozi) The echo "Your Choose is $REPLY" # # variable REPLY dedicated to storing the results of user input echo "$MEN U Price is 20 ";; Lamian) echo "Your Choose is $REPLY" Echoes "$MENU Price is 15";; Mifan) echo "Your Choose is $REPLY" Echoes "$MENU Price is 18";; Daoxiaomian) echo "Your Choose is $REPLY" Echoes "$MENU Price is 12";; Quit) echo "Your Choose is $REPLY" break;; *) echo "Your Choose is $REPLY" echo "Choose a

requires the output on the screen to be "1+2+3+4+5+6+7+8+9+10= calculation results", which is a good example. [[emailprotected] tmp]# echo $ (seq -S " + " 10 " = ' seq -S " + " Ten | BC " 1 +2 +3 +4 +5 + 6 +7 +8 +9 +10 = 55 Echo $ (seq"+") =$ (('seq'+ "ten"))1+2+3+4+5+6 +7+8+9+Ten=[Email protected] tmp]#Echo$(seq-S"+" Ten)=$(seq-S" + " Ten|Xargs Expr) # Note"+"And" + "1+2+3+4+5+6+7+8+9+Ten= -Back to series article outline:http://www.cnblogs.com/f-ck-need-u/p/7048

well. >example.txt Input Sample$ sed ' s/tolstoy/camus/' Camus reads well. Tolstoy writes well.$ sed ' s/tolstoy/camus/g ' Camus reads well. Camus writes well.$sed ' S/TOLSTOY/CAMUS/2 ' Tolstoy reads well. Camus writes well.Sed-n ' 10,42p ' foo.xml print only 10-42 lines3.3 Field HandlingThe Cut command is used to cut down a selected character range or field, and a join is a file that combines a field with a common key value in the record.Awk is mostly used for simple "command-line

Tags: Configuration ideas nbsp Script Practice post awk bash judgment comparison#!/bin/Bash while : DoRead-P">>>"user [["$user"="Q"]] || [["$user"="Q"]] Break [[-Z $user]] ContinueID$user >/dev/NULL [[ $? -eq0]] Cat/etc/passwd|awk-F:'{print $, $NF}'|grep$user | |Echo "User not exist" DoneThe script implements the target to determine whether the user existsMain ideasThe while do statement implements the loopAdd variable $user exit mechanism use "| |

the same as [].(4) between multiple [] and multiple [[]], or any of the mixed intermediate logical operators are or | |.1.5 General Examples:(1) Compare the size of the two integers by defining variables, script arguments, and read-in in a conditional expression (prohibit using if) and alerting the user to the results in the form of a screen output. A total of 3 scripts developed, when using script to pass the parameter and read in the way you need to be a variable is a number, and not to give

for the second partition;(3) for Rootfs to provide bash, LS, cat programs and the library files that depend on;(4) Provide the configuration file for grub;(5) The new hard disk is set as the first boot item and can start the target host normally;8. Write a script(1) can accept four parameters: Start, stop, restart, statusStart: Output "starting script name finished."...(2) Any other parameters, all error exits;9, write a script to determine whether a

-interactive editor, and SED is suitable for editing files in scripts because Vim cannot be used in scripts. Sed the main usage of the increase and deletion of the search, this can see the man manual, there is a lot of practice. Tomorrow I will provide an sed file that will summarize all the uses of SED basically. I hope you will pay attention!Summarize:Today mainly on the shell

I want to practice PHP programs on Linux, environment configuration, which operating system is good? Some say with red hat, I used to own Ubuntu nothing, compile anything need C + + support, Dude, what kind of Linux do you recommend? Reply to discussion (solution) I'm using a centos5.5.Nothing has happened yet.I think this system is good. Debian centos6.4 If you have Ubuntu experience, and just do

=^\ ([^:]*\): [^/]*/[^/]*/\ ([^/]*\] =\1:\2= ')Jones:555-01235. Variable assignment and environment5.1, ReadOnly and ExportTwo similar commands provide management of face-changing, one is readonly, it can make variable read-only mode, and assignment to them is forbidden. In shell programs, this is a good way to create symbolic constants.hour_per_day=24 Assignment valueReadOnly Hour_per_day is set to read-

First, the basic writing process of the practice script:1. Determine the task and the command to complete the task2. Scripting Integration Tasks3. Authorization and test executionSecond, exercise:A. First I create a directory, put the script we write into, so it's not too messy[Email protected] ~]# mkdir-p/root/bin[Email protected] ~]# Cd/root/binB. Start compiling below[Email protected] bin]# VI sysinfo.sh

Learn from this section the main control statements, loop statementsComments, Shell Multiline commentsThe Shell line comment is simple, just add # at the beginning of each line, but he does not provide a special multi-line comment method, so we use a clever way to multi-line comments, using the EOF delimiter to multi-line comments, as follows: 1 #! /bin/sh 2 3 file= "/desktop/file.test" 4 5 5-17 lines

This article explains the advanced knowledge of shell variables.The following is a summary of the knowledge points, about the practice, this article does not involve, but also the small partners to practice their own!For special positional parameter variables in 1.shell, see the following table:650) this.width=650; "Wi