Shell

2. UseThe grep command in a Linux system is a powerful text search tool that uses regular expressions to search for text and print matching lines. The grep full name is global Regular expression Print, which represents the globally regular

$$: The process ID representing the shell script $!: The process ID representing the last executed shell script $?: Represents the return value of the last executed shell command $*: Represents all parameters in the form "parameter one

For more information, refer to:(iii) Play with Me Linux Network service: master server configuration for DHCP service configuration1#! /bin/Bash2ipsag="10.10.10"3dnsip="10.10.10.10"4dn="ns.gr.org"5Cat >/etc/dhcpd.conf 6ddns-update-style

1. Shell Features:To view the command history using the historical command:[Email protected] ~]# historythe user's history record is located in the user's home directory . Bash_history File:[Email protected] ~]# vim ~/.bash_history Quick Actions

In the case of Red Hat Enterprise Linux versions, the contents of Rhel are as follows,/bin to store commands used by ordinary users/sbin storing commands that administrators can executeHome directory for ordinary users such as Zhangshan home

Shell Practice 11.requireA B C D1 2 3 45 6 7 83 5 8 01 2 4 3After handling:T A B C DA 1 2 3 4B 5 6 7 8C 3 5 8 0D 1 2 4 31.first need read the first line as an array.Then append the element in the proper position for file;oldifs= $IFSIFS =$ ' \ n ';

# #! There is a space followed by a space followed by the full path of the interpreter and must be correct.#! /bin/ashPro_path= ""# Testpro is an executable program to be guarded, which guarantees it is always runningProgram= "Testpro"# This script

Under current directory:Find./-size +2048k |xargs Du-b|awk ' {print $1/1024/1024 ' M "$ $} ' |sort-n。。。。。。2.53318m./images3545s_.jpg2.53318m./images607s_.jpg2.53318m./image26s_.jpg2.53318m./image2153654s_.jpg2.63534m./images58s_. Jpg。。。。。。。。Avoid

A simple requirement: the shell implements the process monitoring watchdog function, with the scheduled task to execute a shell script every minute, monitor the process, if the unexpected interrupt then start him, if normal, do not need to do

-------------------------------------- Shell application Tips------------------------------------------A command completion: Tab completion shell command two: Clear or ctrl+l clean screen ctrl+u Erase all previous contents of the cursor history

Linux file system is the hard disk space format into a number of node and block data blocks, the creation of general files, directory creation, will occupy a node, if the creation of a file, the specific data stored in a number of block data block,

1. Historical Order (History,↓, ↑,!) )The default value for history is 1000, which is specified in/etc/profilecommand history, which is used to query recent command histories;Use the arrow keys (↑) to query the previous command;Use the arrow keys (↓)

#!/bin/bash#shell implementation of the fast sequencing of script programming (with the idea of a meta-point at the far right) a= (8 5 3 2 for 4 1 2 3 + 9 for 8 6) temp=buff= #交换函数swap () {buff=${a[$1]}a[$1]= ${a[$2]}a[$2]= $buff}fun () {i=$ ($1-1)

Shell script programming (merge and sort) #! /Bin/bash # shell script sort by merging a = (1 3 5 7 9) B = (2 4 6 8 10 12 14) c = n = 5 m = 7i = 0j = 0 k = 0 while [$ I-lt $ n-a $ j-lt $ m]; doif test $ {a [$ I]}-gt $ {B [$ j]}; thenc [$ k] =$ {B [$

Fast sorting of shell script programming Sorting Algorithm and shell script Programming Algorithm #! /Bin/bash # implementation of fast sorting in shell script programming (using the rightmost element as the element) a = (8 5 10 3 2 93 4 1 2 3 40 9

Shell script sorting (Bubble Sorting), shell script sorting bubble #/Bin/basha = (9 84 51 0 345 1 2 34 1 0) # define an array temp = for (I = 0; I The above is sorted by a custom fixed array, and the following is a user-defined input array.

Shell script sorting (Bubble Sorting) #/Bin/basha = (9 84 51 0 345 1 2 34 1 0) # define an array temp = for (I = 0; I The above is sorted by a custom fixed array, and the following is a user-defined input array.   #/Bin/basha = 'expr $ # + 1' #

Shell script Sorting Algorithm (Bubble Sorting) #/Bin/basha = (9 84 51 0 345 1 2 34 1 0) # define an array temp = for (I = 0; I The array written above is the array sorting defined in the Code beforehand. The following is the array sorting

Linux commands (while, shell parameter usage), linuxshell #! /Bin/bash while IFS =: read name1 name2 name3 name4 # IFS is the specified delimiter when reading content from a file: the separate parts are assigned to corresponding variables

Linux shell and shell -------------------------------------- shell application tips ------------------------------------ command completion: tab key completion shell command 2: clear or ctrl + l clear screen ctrl + u clear all the content before