shell scripting practice programs

1, #!/bin/shThe first line tells the operating system that the interpreter for this script is/bin/sh this executable file2. While loop:#!/bin/shSleep 1; echo "User"; \Sleep 1; echo "Password"; \While true; Do \echo "Output"Sleep 1; \Done3, the shell script realizes the automatic input of Telnet, implements with the pipeline, the last while loop is used to give the last command full execution time(Sleep 1; echo "user"; \Sleep 1; echo "Password"; \Sleep

Integer two-dollar comparison operator The comparer used in [] and test The comparer used in (()) and [[]] Description -eq = = or = Equal abbreviations, equal -ne != Not equal abbreviations, unequal -gt > Greater than greater than -ge >= Greater than or equal to greater equal -lt Less than than similar -le Less than or equal to

The shell itself is a program written in C language, which is a bridge for users to use Linux. Shell is both an imperative language and a programming language. As the command language, it interprets and executes the commands that the user enters interactively; As a programming language, it defines various variables and parameters, and provides many control structures that are available in high-level languag

First part: Linux command line"Linux command line and Shell Scripting Encyclopedia" chapter I: the first knowledge of Linux shell"Linux command line and Shell Scripting Encyclopedia" chapter II: Into the shell"Linux command line a

• Line 6th: Create a test_1 ... 10.txt file • Line 7th: End of loop body CDs, MKDIR, and touch are all programs that come with the system, typically in the/bin or/usr/bin directory. For, does, done is the keyword of the SH scripting language. The concept of shell and shell

What is a shell script sample Let's look at an example: #!/bin/sh cd ~ mkdir shell_tut cd shell_tut for ((i=0; i Example explanation Line 1th: Specify the script interpreter, here is the interpreter with/bin/sh Line 2nd: Switch to the current user's home directory Line 3rd: Create a directory Shell_tut Line 4th: Switch to the Shell_tut directory Line 5th: Cycle conditions, 10 cycles

Learn Shell to now, always thought that they will not commit a very two problems, the result of this book last time made a very 2, integrity not protect AH!!! I'm under the test file path except wildcard * and? What can be used outside the same thing, the result of the $home under the implementation of RM. All right, the egg hurts for the whole afternoon! Return the wood to any one of the configuration files. Warn posterity, do not use RM Test wildcar

Shell Script Introduction Shell is a scripting language You can use logical judgments, loops, and other syntax Functions can be custom-defined The shell is a collection of system commands Shell scripts enable automated operations, which can greatly i

script rotatefile can solve this problem. This script can rename the message to save the file (assuming outmail) is OUTMAIL.1, and for outmail.1 it becomes outmail.2 and so on ... The code is as follows: #!/bin/sh # vim: set sw=4 ts=4 et: ver="0.1" help() {   cat How does this script work? After detecting a file name provided by the user, we perform a 9 to 1 loop. File 9 is named 10, file 8 is renamed to 9, and so on. After the loop is complete, we name the original file 1

# input Check:If [-Z ']; ThenError "Error:you must specify a file, use-h for help"FiFilen= "$"# Rename any. 1,. 2 etc File:For N in 9 8 7 6 5 4 3 2 1; DoIf [-F ' $filen. $n "]; Thenp= ' expr $n + 1 'echo "MV $filen. $n $filen. $p"MV $filen. $n $filen. $pFiDone# Rename the original file:If [-F "$filen"]; Thenecho "MV $filen $filen. 1"MV $filen $filen. 1Fiecho Touch $filenTouch $filenHow does this script work? After detecting a file name provided by the user, we perform a 9 to 1 loop. File 9 is na

detecting a file name provided by the user, we perform a 9 to 1 loop. File 9 is named 10, file 8 is renamed to 9, and so on. After the loop is complete, we name the original file 1 and create an empty file with the same name as the original file.DebugThe simplest debug command, of course, is to use the echo command. You can use Echo to print any variable value in any place where you suspect it is wrong. That's why most shell programmers spend 80% of

1. Linux Scripting Basics1.1 Basic Introduction to grammar1.1.1 StartThe program must start with the following line (must be placed on the first line of the file):#!/bin/shThe symbolic #! is used to tell the system that the parameters behind it are the programs used to execute the file. In this example we use/BIN/SH to execute the program.When you edit a good script, you must also make it executable if you

The role of the shell: between the system kernel and the user, is responsible for interpreting the command line. · Shell programs that are used by default after logging in, typically/bin/bash Different shell internal instructions, operating environment, etc. will differ [Email protected] ~]# Cat/etc/shells /bin/sh /bin

Student's score is 0-100, please enter again! [[emailprotected]shell]#shtest7.sh Please enter student's score: dagfag This is not a number please enter it again!! [[emailprotected]shell]#shtest7.sh Please enter student's score: 89 good!Using the example above can see the use of case judgment, although the example is not very good, but a more comprehensive practice