Linux

1.Linux Link ConceptThere are two types of Linux links, one called hard links, and the other called Symbolic links (symbolic link). By default, the LN command produces a hard link.1.1 Index nodesAn index node refers to a data structure in many

====================================================When the Linux nginx reaches a high number of concurrency, the number of TCP time_wait sockets often reaches 20,000 or 30,000, so the server can easily be dragged to death.In fact, we can simply

Issue:ping:unknown HostRoot Cause:linux cannot resolve DNSAction:1. Check the network card settingscommand:root user under ifconfig-aRoot user under vi/etc/sysconfig/network-scripts/ifcfg-eth02. Ping the gateway to confirm that it can ping the 3.

 Vi/etc/sysconfig/iptables-A input-m state–state new-m tcp-p tcp–dport 80-j ACCEPT (allow 80 ports through the firewall)-A input-m state–state new-m tcp-p tcp–dport 3306-j ACCEPT (Allow 3306 ports through the firewall)Special tips:Many netizens

1. IntroductionDu view the directory size, DF to view disk usage.2. DuDisk usage(1) Basic functions Recursively view the size of all files under a folder(2) Common parameters: -h,–human-readable display dimensions in a more readable manner (e.g. 1K 2

Now you can improve the client program so that it can connect to any host that has a name, this time not connecting to the sample server, but connecting to a standard service, so that you can demonstrate the port number extraction operationThe.Most

The MV command is the abbreviation for move, which can be used to move files or rename files (rename), which is a common command under Linux, often used to back up files or directories.1. Command format:MV [option] source file or directory

in Linux, use the pwd command to view the full path to the current working directory. Simply put, you will have a current working directory every time you operate in a terminal. When unsure of the current location, PWD is used to determine the exact

Linux awk command DetailsIntroductionAwk is a powerful text analysis tool, with the search for grep and the editing of SED, which is especially powerful when it comes to analyzing data and generating reports. To put it simply, awk reads the file

1. PWD: Show working directory path -P: Show actual physical path -L: Show link path 2. CD: Change the working directory path CD: Go to User's home directory cd~: Go to User's home directory cd-: Returns the

1. View several CPU and CPU cores# Cat/proc/cpuinfo2. View system load, load averageW,top the average load in 1 minutes, 5 minutes, 15 minutes.Meaning of R/b/si/so/bi/bo in 3.vmstatR the number of processes running and waiting for CPU time slices is

OverviewIn contact with network programming, we often deal with various IO-related concepts: synchronous (synchronous), asynchronous (asynchronous), blocking (blocking), and non-blocking (non-blocking). On the difference of concept see a friend

To view text:1.cat: Connect and display textInverted display of the Tac:cat-N: Add rows at the beginning of each line display-E: line breaks displayed per row-A: Displays all, including text and various special symbolsThe text newline character for

A detailed description of compression decompression commands under LinuxZip-r myfile.zip./*All files and folders under the current directory are compressed into myfile.zip files, and-R indicates that all files in the subdirectory are compressed

1.linux File System Architecture/root directory root|--mnt/| |--sdcard/mount point| |--usb0| |--cdrom|--home| |--soft01 2. Absolute path:/start pathAbsolute path is the location starting from the directoryRelative path: Not the/start pathThe

After the PIP upgrade to 7.0, when using the HTTP image for package installation and upgrade, there are often the following tips: Collecting BEAUTIFULSOUP4The repository located at Mirrors.aliyun.com are not a trusted or secure host and is

chmod Command[Email protected] ~]# ls-lTotal 104Drwxr-xr-x. 3 root root 4096 Jul 2 22:34 222See here Drwxr-xr-x , R=4,w=2,x=1, so rwx=4+2+1=7,r-x=4+1=5, r-x=4+1=5, Therefore, the file permission can be represented as 755[email protected] ~]# chmod 74

When doing Android, want to make GIF to demonstrate the effect. Find a simple and feasible way:The app runs in the simulator, recording with the recorder software, and then turning the video into GIF.System: Ubuntu 15.04Screen Recorder software:

Experience Visual Studio 2015 Windows Forms Application Development and Maintenance I had not waited for Visual Studio 2015 in the middle of the night, so I had to take a rest. The Time Zone in North America is later than that in Beijing. This

Four tips for Linux mkdir, tar, and kill commands We have been doing a task in a regular way until we know there are better solutions. As a follow-up of the Linux tips and tricks series, I will introduce four tips that can help you in various