Linux

chgrp Change Group changes the user group that the file belongs to eg. Chgrp-r User 1.txt[[email protected] test]# ll   Query the files and properties under the test directory total 0                   is now empty, no files [[email protected ] test]

Analysis of memory relationship between Linux and JVMIntroductionOn some servers with physical memory of 8g, the main running of a Java service, the system memory allocation is as follows: Java service JVM heap size is set to 6g, a monitoring

1. IntroductionThe Wireless Client Configuration tool under Linux has wireless tools for Linux and WPA supplicantThe difference between the two is that the former support network is not encrypted or WEP encryption, the latter supports the WPA

Reproduced:The following is a list of Linux system calls that contain most of the common system calls and functions derived from system calls. This is probably the only list of Linux system calls you can see on the Internet, even if it's a simple

The top command is a common performance analysis tool under Linux that shows the resource usage of individual processes in the system in real time, similar to the Task Manager for Windows. Here is a detailed description of how it is used. Top is a

The first is the fork () function.  Apue 8.3. A clearer explanation can be http://blog.csdn.net/lingdxuyan/article/details/4993883 and http://www.oschina.net/question/195301_62902.One thing to add: After the fork returns, each file or socket in the

Execute strlwr function times wrong. The source program such as the following:#include #include void main () {char s[10]={"China"}; printf ("%s\n", STRLWR (s)); return 0 ;}Error content such as the following:eg6527a.c:in function ' main ':Eg6527a.c:

Raid0: StripPerformance boost: Read, write nRedundancy capability (fault tolerance): noneSpace utilization: NSAt least 2 pieces of disk1: MirrorPerformance improvement: Write performance decreased, read performance improvedRedundancy capability:

Chown the owner of the specified file to the specified user or group, the user can be either a user name or a user ID; a group can be a group name or a group ID; a file is a space-separated list of files to change permissions, and wildcard

Linux from program to processVamei Source: Http://www.cnblogs.com/vamei Welcome reprint, Please also keep this statement. Thank you!How does the computer execute the process? This is the core issue of computer operation. Even if the program has been

The Linux du command also looks at the space used, but unlike the DF command, the Linux du command is a view of the space used by the file and directory disks, or some difference from the DF command.1. command format:du [Options] [file]2. Command

let's look at a more basic usage:Tcpdump-i eth0Among them, eth0 is the parameter value, which indicates the network port that needs to grab the packet, this is a necessary parameter oh.Specific parameters and meanings of tcpdump:-I: Specifies the

GRUB Full name GNU GrubVersion: Grub (GNU grub 0.97)GRUB2 is the rewritten version of Grub, which can be said to be different.Wiki:https://zh.wikipedia.org/wiki/gnu_grubGrub has a total of 3 phases:bootloader:1st StagePartition:filesystem driver, 1.5

Operations and research and development staff, login server operation is becoming more and more common, in order to secure, it is necessary to log on every operation of the system, in order to facilitate later understanding, mastery, audit.Simple

Content Introduction1, Part IV lesson five: source compilation, installation convenience 2 , Part VI lesson: dns and domain name, what to do source code compilation, installation

Console Terminal: Tty1-tty6Virtual Terminal: ptsConsole Toggle Shortcut: CTRL + (SHIFT) +alt + F2-F6 (some notebooks require FN)Switch to another terminal: Alt + F1-f6 + (Fn)The open terminal can be viewed via the filter command: PS aux | grep ptsPS

Run native Debian (non-chroot) on Android devices) Recently, we found that it is feasible to switch_root access Debian by modifying the initramfs file of the android kernel and adding a BusyBox. In BusyBox, you can directlyinsmod *.koThe kernel

Zookeeper permission management and Quota management The ACL and Quota mechanisms of Zookeeper have less information on the Internet. Here is a summary for your reference. 1 Zookeeper ACL The permission management of ZooKeeper, that is, the ACL

Spring Boot + Nginx + Tomcat + SSL configuration notes If your tomcat application requires ssl to enhance security, one way is to configure tomcat to support ssl, And the other way is to use nginx reverse proxy tomcat, then, configure nginx as https

RedHat Performance Tuning Performance Optimization aims to improve performance and reduce the impact of resource consumption and applications on the system. If it is implemented prematurely or without performance evaluation, performance optimization