Shell

The shell itself is a program written in C, which is a bridge for users to use Unix/linux, and most of their work is done through the shell. the shell is both a command language and a programming language. as a command language, it interprets and

Resolve Bash Shell pin this newspaper error ': not a valid identifierWhen you edit the script in the shell, the runtime appears "': not a valid identifier", or it will appear (: Command not found, many inexplicable symbols) is likely you to edit

#!/bin/bash# Test color for scriptred_color= ' \e[1;31m 'green_color= ' \e[1;32m 'yellor_color= ' \e[1;33m 'blue_color= ' \e[1;34m 'pink= ' \e[1;35m 'res= ' \e[0m 'if [$#-eq 2] Thenecho "Usage: ' basename $ ' content {Red|blue|yellow|pink|res|green}"

In Shell learning, we encounter these two symbols: anti-quote (') and $ (), what are the differences between them?We all know that in bash, anti-quotes and $ () are used for command substitution, and command substitution is used to reorganize the

Usage of the Linux Cut commandFont: [Increase decrease] Type: Reprint time: 2013-10-03 I want to commentCut is a selection command that analyzes a piece of data and takes out what we want. In general, the selection of information is usually for

Http://blog.chinaunix.net/uid/21411227/cid-63616-list-1.html1. Determine the file type –b Returns True when file exists and is block　　-C Returns True when file exists and is a character　　-D returns True when pathname exists and is a directory　　-E

The first part,1. View TCP connection StatusNetstat-nat |awk'{print $6}'|sort|uniq-c|sort-Rnnetstat-N | Awk'/^tcp/{++s[$NF]}; END {for (a in S) print A, S[a]}'netstat-N | Awk'/^tcp/{++state[$NF]}; END {for (key in) print key, "\ T",

In the Linux shell programming, the process control structure and the statement, also is the shell script the emphasis, does not understand the friend, follows the script small compilation together to study.Linux control flow structure learning.One,

AwkI. Introduction of AWKscripting languageVariable..... Process Control array functions        use awk for Data statistics        1 Number of users in the statistical system, number of built-in users          2 statistics Site Server traffic for

Some time ago in the study shell script, the last mention of the SED mode space and maintain the concept of space, but has not studied well, these two days studied, so it sent, not very comprehensive, just for your reference.Keep the space sed under

The code is as follows:Url= "/VAR/WWW/HTML/RRA/150/9517.RRD/VAR/WWW/HTML/RRA/256/11345.RRD/VAR/WWW/HTML/RRA/150/9518.RRD" fff= ' echo   $url  | awk  ' {print nf} ' for ((i=1;i> /tmp/test${x}done                            ff= '

#!/bin/bash# Test color for scriptRed_color= ' \e[1;31m 'Green_color= ' \e[1;32m 'Yellor_color= ' \e[1;33m 'Blue_color= ' \e[1;34m 'pink= ' \e[1;35m 'res= ' \e[0m 'If [$#-eq 2]Thenecho "Usage: ' basename $ ' content

There was a time when the shell was not written, and today I occasionally see a shell file content. There are some special usage, only feel the impression but can not say the specific function, and then checked. By the way record down, prepare for

Print variables[Email protected] shell]# echo $PATH/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/binCustom variables[[email protected] shell]# a=1 custom variable [[email protected] shell]# echo $a print variable 1Write a script

Single quotes:What you see is what you get: The contents of the single quotation mark are output as-is, or what you see in single quotes is what you output.Double quotes:Output the contents of the double quotation marks: If there are commands,

1. Create 10 files in the/test directory using a For loop such as: Test-1,test-2,... test-10mkdirsh.sh#!/bin/bashFor i in ' seq 10 'Do[!-d/test] && mkdir-p/testtouch/test/test-$iDonechmod +x mkdirsh.sh2, in the/test directory to quickly create 10

This article describes the most common tools for using the shell to process text under Linux:Find, grep, Xargs, Sort, uniq, tr, cut, paste, WC, sed, awk;The examples and parameters provided are the most commonly used and most practical.I use the

Often read some of the books about Linux still feel unable to fully grasp this knowledge can not be fully mastered as long as you can achieve proficiency in the use of after all, do research and development is able to quickly make products to sell

Both Echo and printf in the shell can be used as output, and printf is an enhanced version of EchoShow escape charactersecho \ "Abcdef\" ">>> "ABCdef"Show variablesAge=23echo "My Age is $age">>>my name is 23In the process of use, in order to avoid

This lesson content:1.      Two dispatching modes of taskschedulerbackend and Schedulerbackend2.     fifo and fair 3.     task allocation of data local resources I. Scheduler run process (Spark-shell angle) 1. Start spark-shell When we spark-shell