linux practice test

base name; Further use Egrep to remove its directory name (note(1)directory name, not directory path);(1)echo/etc/rc.d/init.d | egrep-o "[^/]+/?$"(2)echo/etc/rc.d/init.d | egrep-o "/.*/"6. Find all files that are not root, bin or hadoop under the/usr directory;find/usr-not-user root-a -not-user bin-a-not-user hadoop 7, one day the system was invaded, hackers in your system to leave the Trojan file:you now need to find all the files on the current system that are not owned by the master or grou

In Red Hat Enterprise Linux 5.0 server, if NFS fails, you can check the problem from the following aspects. 1.1 troubleshooting ideas 1) whether the NFS client and server load is too high, and whether the network between the server and the client is normal. 2) the file/etc/exports is correct. 3) restart the NFS or portmap service if necessary. Run the following command to restart portmap and NFS: Service portmap restart feedom.net Service nfs start 4

as its shell name; # Useradd Ngnix# Useradd Zabbix# Useradd Tomcat# Useradd Hadoop# Useradd-s/sbin/nologin Nologin# cut-d:-F 1,7/etc/passwd |grep "^\ ([[: Alpha:]]\{1,\}\):. *\1$"4, find A word in the/etc/rc.d/init.d/functions file (the middle of the word can be underlined) followed by a set of parentheses line;#grep-O "\ ([[: alpha:]]\+_*[[:alpha:]][[:space:]]* (. *) \)"/etc/rc.d/init.d/functions5, use echo to output a path, and then egrep find its path base name; further use egrep to remove i

large as"else errorFiThe test results are as follows:[Email protected] shell]# bash 6.sh+--------------------------------------------------------+| Function of the script is to compare, numbers size || Instructions:num_compare.sh NUM1 num2 || Example:num_compare.sh 11 22 |+--------------------------------------------------------+[[email protected] shell]# bash 6.sh a 1+--------------------------------------------------------+| Function of the script

/bin/backup.sh, can be implemented daily/etc/directory backup to/root/etcyyyy-mm-dd4. Write script/root/bin/disk.sh, showing the maximum space utilization value in the current hard disk partition5. Write Script/root/bin/links.sh, show the IPV4 address and connection number of each remote host connecting to this host, and sort by the number of connections from large to small' Ifconfig |egrep-o ' \6. Write script/root/bin/sumid.sh, calculate the sum of the ID of the 10th user and the 20th user in

serious as you think. You can consider using it in an online environment. DRDB + Heartbeat is a mature application and we recommend that you master it. I have used this combination to replace EMC shared storage in many occasions. After all, more than 0.3 million of the price is not acceptable to every customer.18. No matter how mature the design scheme is, we recommend that you configure the Nagios monitoring machine to monitor our servers in real time. Email and SMS Alarms can be enabled. Afte

"Print Current Task info\n"); -Printk"pid\ttgid\tprio\tstate\n"); - for_each_process (pcurrent) { thePrintk"%d\t",pcurrent->pid); -Printk"%d\t",pcurrent->tgid); -Printk"%d\t",pcurrent->prio); -Printk"%ld\t",pcurrent->State ); + } - return 0; + } A Static void__exit Print_exit (void) at { -PRINTK (Kern_info"Module finished!\n"); - - } - - Module_init (print_init); inModule_exit (Print_exit);3. Compile the moduleNext write Makefile.1 obj-m:=printname.o2 current_path:=$ (shell pwd)3 linux

1, describe the CENTOS6 system boot process;1) Load the hardware information of the BIOS and self-test, and obtain the first bootable device according to the configuration;2) Read and run the boot Loader (grub, Spfdisk, etc.) of the MBR in the first boot device;3) According to the configuration of boot loader loading Kernel, Kernel will start to detect hardware and load drivers;4) After the hardware driver is successful, Kernel will actively call the

Linux Process understanding and practice (4) wait function processing botnetsWait background When a child process exits, the kernel sends a SIGCHLD signal to the parent process. The exit of the child process is an asynchronous event (the child process can be terminated at any time when the parent process is running) When a child process exits, the kernel changes the child process to a zombie state. This pro

Linux multithreading practice (4) specific data of threads In a single-threaded program, we often use "global variables" to share data among multiple functions. However, in a multi-threaded environment, because the data space is shared, therefore, global variables are shared by all threads. However, sometimes it is necessary to provide a global variable private to the thread in the application design, which

Linux practice engineer study Note 2: common system management commands redhat-config-network-tui is a unique configuration tool for redhat. After configuring network parameters with this command, writes to the/etc/sysconfig/networking/profiles/directory, and takes precedence over network-scripts/ifcfg-eth0 1. useradd redhat 2. passwd redhat 3. su- 4. exit 5. df-h partition 6. du-sh/* size of the space used

sent, call the function gethostbyname () to resolve Host B, and convert the hostname to a 32-bit IP address. This process is called DNS domain name resolution .Step b:ping program sends an ICMP echo packet to the destination IP addressStep c: Convert the destination host's IP address to a 48-bit hardware address , send ARP request broadcasts within the LAN, and find the hardware address of Host B.Step d: After the ARP protocol layer of Host B receives the ARP request from host A, the hardware a

:/sbin/shutdownHalt:x:7:0:halt:/sbin:/sbin/haltBash:x:505:505::/home/bash:/bin/bashNologin:x:508:508::/home/nologin:/sbin/nologin 5. Display the default shell and UID of root, CentOS, or User1 user on the current system (please create these users beforehand, if not present) [[email protected] ~]$ grep-e ' ^ (root|centos|user1) '/etc/passwd | Cut-d:-f1,3,7Root:0:/bin/bashCentos:509:/bin/bashUser1:510:/bin/bash 6, find a word in the/etc/rc.d/init.d/functions f

is able to receive a **/Comprehensive case1) Create child process and parent process;2) Register SIGINT non-real-time signal and sigrtmin real-time signal, and add these two signals to the process shielding signal Group;3) Register user-defined signals;4) The sub-process sends 5 non-real-time signals and sends 5 real-time signals;5) The sub-process then sends the SIGUSR1 to unblock the sigint,sigtrmin signal.6) Observe the difference between real-time and non-real-time signalsprogram example vo

int) int{Return X+y}Func Sub (x, y int) int{return x-y}Func swap (x, y String) (string, string) {return y, X}Func split (sum int) (x, y int) {x = SUM*4/9y = sum-xReturn}var c, Python, Java boolFunc Main () {Fmt. Printf ("Now you have%g problems.\n", Math. SQRT (7))Fmt. Println ("My favorite number is", Rand. INTN (10))var u64 uint64 = 1Fmt. Printf ("%d%d\n", U64, Int64 (U64))Fmt. Println (Add (42, 13))Fmt. Println (Sub (42, 13))A, B:=swap ("Hello", "World")Fmt. Println (A, B)Fmt. Println (Split

interrupt wait. Write 0 Clear flag.The generation and processing of interrupts is explained in detail in the 488-page low-end Comment:As above, by the 2nd, the interrupt source has 3:1 bytes (8bit) of data sent or received, the host (at this time the 2,440-bit slave) call or slave (2440 host) address to the address sent by the host match; arbitration failure (specific follow-up instructions).Combined with interrupt and host send, receive block diagram, the agreement has a whole grasp, now the p

System ubutnu12.04-php 5.2General steps:Download the corresponding PHP version of the extension sourceUnzip and enter the directoryPerform phpize precompilation (generic and PHP execution files in one directory)./configure--with-php-config=php Path/php-config (If an error occurs installing autoconf)Make MakeinstallConfiguring the php.ini file to open the corresponding extensionRestart PHP Service (PHP-FPM or Apache)——————————————————————————————Lifting Li:Now compile and install the MySQL exten

Tags: regular practiceRegular practice1.通过awk获取IP地址[[emailprotected] ~]# ifconfig eth2 | grep inet inet addr:10.3.151.25 Bcast:10.3.151.255 Mask:255.255.255.0 inet6 addr: fe80::250:56ff:fe80:6e7e/64 Scope:Link[[emailprotected] ~]# ifconfig eth2 | grep "\binet\b" inet addr:10.3.151.25 Bcast:10.3.151.255 Mask:255.255.255.0[[emailprotected] ~]# ifconfig eth2 | grep "\binet\b" | awk ‘{print $0}‘ inet addr:10.3.151.25 Bc

[Email protected] ~]#/w29.sh 2/12.00[Email protected] ~]#/w29.sh 10/52.00[Email protected] ~]# VI w29.sh[Email protected] ~]#[Email protected] ~]#./w29.sh./w29.sh:line 3:syntax error near unexpected token ' fi './w29.sh:line 3: ' fi [$#-ne 3]; Then[Email protected] ~]# VI +3 w29.sh[Email protected] ~]#[Email protected] ~]#./w29.shPlease input 3 parameter[Email protected] ~]#30. Ask for the sum of all even numbers within 100 and the sum of odd numbers.For:#!/bin/bash#Sum1=0Sum2=0For I in $ (SEQ 1

tle | | echo "Error"For:If the little user and his or her home directory do not exist, the output "Error", or delete the user, and his home directory, the loop delete.If the little user and his or her home directory do not exist, create the user and force the creation of their home directory/home/little; otherwise output "Error"Useradd command:-D: Create home directory-M: Create User with home directoryCases:[[email protected] ~]# LS/Backup boot etc lib lost+found misc net proc sbin SRV tmp var