linux scripting basics

operating system. Operating systems have a vested right to them. It also provides the necessary environment for its execution.2. What are the salient features of Linux? compatible with UNIX free software. Source code exposes high performance, strong security easy to customize and re-develop interoperability high full multitasking and true 32-bit operating system Widely used in the server market and embedd

)Command WC to statistic text information-L only count rows-W only count words-C only counts bytes-M only counts the number of charactersCommand sort to sort text content-R for reverse order-N Sort By numbers-F ignores case-U Delete Duplicate rows-T C uses C as a delimiter to sort columns-K x specifies which column to sort based on when the column is sorted based on the specified characterCommand sort-u can be used to delete duplicate rowsCommand Uniq to delete duplicate rows (only adjacent dupl

问题来自Linux教材，答案自我整理难免会有不足之处。这是我Linux期末的总结1. Can there be several types of partitions on a hard drive? How many can each have? (Can each partition install an operating system?) ） The hard disk partition has three types of partitions: primary partition, extended partition, logical partition, one hard disk can divide up to 4 primary partition, or 3 primary partition plus one extended partition, the ext

(that is, permission to access the directory ). Therefore, the default file permission is 777, that is, rwxrwxrwx. But this is not complete yet. See the following (2 ). (2) initial permissions The above is the default permission for files or directories in Linux, while umask in Linux indicates that files or directories are masked at the beginning of creation (mask) permissions. Therefore, if umask is 022,

Basics of Linux 1. computer components and functions.Computer systems are mainly divided into hardware systems and software systems. (1) The hardware system consists of five parts, including: Controller: scheduling program, Data, address, coordination of various computer work and access to memory and peripherals; Host: data processing; Memory: storage program, signal, command, data and other information, a

numbers? Represents a letter or a number"Case" ls A * ls a? LS f080[1-6].tifescape character \ "Case" ls/mnt/win1/my\documentssingle quotation marks: Do not process any variables and commands "Case" Echo ' Welcome $NAME, the date is date 'double quotes: Handling variables but not processing commands"Case" echo "Welcome $NAME, the date is date"Reverse quotation marks: Each word in the quotation mark as a command, if the variable is evaluated first and then treated as a command "Case" echo "Welco

a file, the following describes the file type.* Use the LS command and the file command to view the files type(1)-: normal file.(2) d: Directory, directory is also a file, directory is the mapping of file paths.(3) B: One of the device file types, called the block device, the device Access feature is randomly accessed by block.(4) C: One of the device file types, known as the character device, the device access characteristics are linear access, that is, sequential reading of data.(5) L: Symbol

I. Introduction of SELinuxSELinux (Secure enhanced Linux) security-enhanced Linux is a new Linux security policy mechanism developed by NSA for computer infrastructure security. SELinux allows system administrators to be more flexible in defining security policies. SELinux is a security architecture that is integrated into the

Article Title: Linux script basics. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. 1. Linux script compiling

server software, such as Apache (WWW server), Sendmail (mail server), VSFTPD (FTP server), Squid (proxy server), etc., so there is no need to purchase additional software, Can directly use Linux as a full-service network server.4.the kernel version number of Linux is composed of three numbers , generally expressed as x.y.z, such as 2.4.18. Where:X represents the major version number, which is usually relat

]:~/test$ chmod +x start[emailprotected]:~/test$ *bash: start: command not found[emailprotected]:~/test$ PATH=$PATH:$PWD[emailprotected]:~/test$ *helloFirst enter the test directory to do the experiment, do the experiment when we create a new directory, in the inside to do is very safe, to prevent the destruction of the outside directory structure or misoperation caused by the hidden trouble.After writing the echo Hello string to the start file, it means that the test directory has a file start,

+++++++++++++++++++++++++ +++++shell Foundation +++++++++++++++++++++++++++++++1. Shell overviewShell definition:The Shell is a command-line interpreter that provides users with an interface system-level program that sends a request to the Linux kernel to run the program, allowing the user to start, suspend, stop, and even write programs with the shell. The shell is also a very powerful programming language, easy to

the logs directory. Note that if the logs directory does not exist, the command renames info to logs.MV Info/logsIf you move all files and directories under/usr/student to the current directory, the command behavior:mv/usr/student/* .RM Command : Delete a file or directoryRM [Options] NameParameters: -I ask for confirmation before deleting. -F Even if the original file attribute is set to read-only, it is deleted directly without confirmation. -R the directory and the followin

Linux network server configuration basics-Linux Enterprise Application-Linux server application information. The following is a detailed description. To create a Secure Linux server, you must first understand the meaning of the configuration files related to network services

with Multi-user.target. The 5th run level is replaced with Graphical.target. Runlevel3.target and Runlevel5.target are symbolic links that point to Multi-user.target and Graphical.target, respectively.Switch to the 3rd run level[Email protected]~]# systemctl isolate Multi-user.targetOr[Email protected]~]# systemctl isolate Runlevel3.targetSwitch to the 5th run level[Email protected]~]# systemctl isolate Graphical.targetOr[Email protected]~]# systemctl isolate Runlevel5.target"Set default ru

Tags: ctime linux Basics----understanding of atime MtimeThere are often cases where the file's time attribute is used, and there are three file-related time attributes under Linux. Atime,ctime,mtime. I also often confused, each encounter will be human flesh search, leisure time to prepare this knowledge thoroughly understand. Read the authoritative documents, wri

Linux Getting Started Basics command (iv)File system and Directory structure:650) this.width=650; "Src=" http://upload-images.jianshu.io/upload_images/6144185-41b85fb3a44d5f8a?imageMogr2/ auto-orient/strip%7cimageview2/2/w/1240 "style=" Border:0px;vertical-align:middle;height:auto; "alt=" 1240 "/>1, the file and is organized into a single inverted tree structure2, file system from the root directory, with "

Linux Basics (ii)Actions related to user groups and permissionsOne, useradd command options:–u: Specifies the UID of the user useradd–u mu #指定mu的UID为100–g: Specifies the group to which the user belongs useradd–g Mark Mu #指定mu的所属群组为mark–d: Specifies the user's home directory useradd–d/home/family mu #指定mu家目录为/home/family–c: Specify user's note information useradd–c "mu_test" mu #mu的备注信息为 "mu_test"–s: Specifi

Linux basics-shutdown and restart commands such as shutdown and reboot, shutdownrebootI. Functions of the shutdown and restart command I believe that people who have been in touch with computers, especially for windows systems, will feel a little stuck if they have been using it for a long time without restarting. However, after the entire system is restarted, it seems that the system is no longer running.

Http://blog.chinaunix.net/uid-20564848-id-73208.htmlKernel Documentation:[Email protected] documentation]# pwd/usr/src/kernels/linux-2.6. +/documentation[[email protected] documentation]# lsxx-INDEX I2O Parport.txtabi IA64 Pciaccounting ics932s401 PCMCIAACPI IDE Pi-Futex.txtaoe InfiniBand pnp.txtapplying-patches.txt initrd.txt powerarm input POWERPCA Tomic_ops.txt Intel-IOMMU.txt ppsauxdisplay intel_txt.txt prctlbad_memory.txt i