-i sum=0For I in {1..100}; DoIf [$[$I%3]-eq 0]; ThenLet sum+= $IFiDoneecho "The sum is: $sum"2. Calculate all the odd and all the even and all the numbers within 100 andCopy CodeThe code is as follows:#!/bin/bash# echo "Exercise"Declare-i sum1=0Declare-i sum2=0For I in {1..100}; DoIf [$[$I%2]-eq 0]; ThenLet sum1+= $IElseLet sum2+= $IFiDoneecho "The even sum is: $sum 1"echo "The Oddnumber sum is: $sum 2"3. Determine the type of file under/var/log:If it
Label: des style HTTP color Io ar strong for SP ### Continue to fix the bash vulnerability in the debian7 wheezy version by performing the following operations: 1. Test whether upgrade is required # Env x = '() {:;}; echo vulnerable 'bash-c "echo this is a test"# The following figure is displayed. Upgrade required. Vulnerable This is a test 2. Offline upgrade ### Many servers cannot go out of the Inter
Red Hat finds a security vulnerability named bash bug in bash shell. When a user accesses the vulnerability normally, the vulnerability allows attackers to execute code like in shell, this opens the door for various attacks. It is reported that its severity exceeds the previous "heartbleed" vulnerability. Detection Method
$ env x=‘() { :;}; echo vulnerable‘ bash
The default shell of hp ux is POSIX, which is not easy to use. Replace it with bash!
Confirm hp ux version and architectureRun uname-a, the version number (such as B .11.31) and the architecture (such as ia64) are displayed, and then search for bash at the address below.Http://hpux.connect.org.uk/hppd/hpux/Download the bash version with the same version and arc
Linux bash script for one-click installation of PowerShell
Description
Currently, PowerShell in Linux is equivalent to pash. I hope you will focus on mono and pash. One-click installation scripts include for CentOS6, centos7, and Ubuntu 14.04 ubuntu 14.10.
The installation script is installed using yum or apt. mono is the latest official version. Compile and install the latest version of pash and generate two commands:
Mybuild is used to compile pash
basis for many derivative shells, many of which are now applied in typical Linux systems. Figure 1 demonstrates the series of important shells. Bourne shell leads to the development of Korn shell (ksh), almshells (ash), and popular Bourne Again shell or Bash. C shell (csh) is under development when the Bourne shell is released. Figure 1 shows the main series, but does not show all the influences, and does not show shell with significant contributions
1 shell overviewThe shell is a command interpreter that provides the user with an interface system-level program that sends a request to the Linux kernel to run the program. The user can start, suspend, stop, or even write some programs with the shell.The shell is a powerful programming language that is easy to write, easy to debug, and highly flexible. The shell is a scripting language that interprets execution and can invoke Linux system commands directly.The shell is usually divided into two
Deletes the specified variable. The variables are not actually deleted, but are not exported to the execution environment of the subsequent directives.
-p lists all the environment variables that the shell assigns to the program.
You can view all current environment variables by typing export only. If you want to add some new paths (such as/bin/bash) to an environment variable (such as path), you can use the following command formatExport Pa
Vulnerability backgroundA very serious security vulnerability (vulnerability reference https://access.redhat.com/security/cve/CVE-2014-6271) has been found in the Linux official built-in bash. Hackers can exploit this bash vulnerability to fully control the target system and launch an attack, in order to prevent your Linux server from being affected, based on the Linux official solution given on September 2
pressure too much baggage. Weekly weekend to give yourself a little vacation, complete indulgence. Don't want to study, just want to play. No, it's pretty good, too.Always believe that no brain nonsense: love to laugh, the luck will not be too bad. Happy people, bad luck will be far away.
An operating system includesHardwareKernelShellHardware is just a bunch of non-thought parts. Only the hardware, the computer is completely unable to work. Ju
A know bash this shell
1 management of the entire computer hardware is actually the operating system's core, this kernel needs to be protected, so our average user can only through the shell to communicate with the kernel, so that the kernel to achieve the work we want to hit.
2 as long as the interface of the application can be manipulated can be called shell
3 Bash
Apple said in late Thursday that the vast majority of Mac users would not be at risk because of the "Shellshock" of recently confirmed bash software vulnerabilities, Reuters reported. Security experts have previously warned that Shellshock will affect operating systems including Mac OS X. "Most OS X users are not at risk," said Bill Evans, an Apple spokeswoman, Bill Evans. He said that since Apple shipped the comp
First, understand the computer hardware components:Von. Neumann architecture defines the computer has the arithmetic, the controller, the memory, the input device, the output device five major parts, also has one principle is: must be the binary program to be able to run in the system, it can only process the binary file. Therefore, the source code of the program needs to be compiled into binary.Second, the
Associated question: www. zhihu. comquestion20244763 if the programming language can be used as a system Shell and is positively related to its popularity, why does Python not become a standard system Shell? Is it more economical to use Python (or other) as the system Shell than Bash or POSIXShell? Associated Issues: http://www.zhihu.com/question/20244763
If the programming language can be used as a system Shell and is positively related to its popul
RedHat 6.4x64 and x86 update bash
X64 Installation
Download bash
Bash-4.1.2-15.el6_5.2.x86_64.rpm
Http://mirror.centos.org/centos/6/updates/x86_64/Packages/bash-4.1.2-15.el6_5.2.x86_64.rpm
Install a new bash package
Chmod U + x b
CVE-2014-6271 Bash Security Vulnerability mac OS X 10.9 repair process, cve-2014-6271bash# DetectionOpen the command line and enter the following content:
env x='() { :;}; echo vulnerable' bash -c "echo this is a test"
If the following is returned, upgrade as soon as possible.
vulnerable this is a test
# Upgrade
Check the current version. Mine is 3.2.51 (1)
Bash shell Command (1), bashshell command
Address:Http://www.cnblogs.com/archimedes/p/bash-shell1.html, Reprinted, please specify the source address.Ls command
Ls is used to list the contents of a directory. It is one of the most commonly used commands. The format of ls is as follows:
Ls [Option] [directory name or file name]
Main parameters:
. Options Main Parameters-A, -- all: Do not hide any items starti
BASH: Procedural programming, in order to accomplish more complex tasks, support sequential execution, select execution, loop executionSequential execution: From left to right, execute command sequentially.Select Execute: Select to execute a different code fragment based on the execution status result of the condition (condition).Loop execution: Determines whether to enter the loop according to the execution status result of the condition (condition).
The technical skills here were originally from Google's "testing on the Toilet" (Tott). Here is a revised and amplified version. Script Security
All of my bash scripts start with the following lines:
#!/bin/bash
set-o nounset
set-o errexit
Doing so avoids two common problems: referring to an undefined variable (the default is "") the command that failed is ignored
It should be noted that some o
Http://zhidao.baidu.com/link?url=bwwK8H_9R06Kw8qpu5puh_s0Bb50YrOi9qsNvBe8ZKOteC_zfV8hJUPqIcQWJohLcH5jBgSlNJ5_ 5hqf-e1w-tlrpqnoa_zbcxdyvyzmopm
The default shell of the Linux operating system is the Bourne Again Shell, an extension of the Bourne shell, called Bash, which is completely backwards compatible with the Bourne shell and adds and enhances many features based on the Bourne shell. The/bin/sh in the Gnu/linux operating system is a symbolic link
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