Linux

Open EDIT: Vi/etc/sysconfig/iptablesRestart Firewall: Service iptables restart# Firewall configuration written by System-config-firewall# Manual Customization of this file are not recommended.*filter: INPUT ACCEPT [0:0]: FORWARD ACCEPT [0:0]: OUTPUT

The Vmstat command is the most common Linux/unix monitoring tool that can show the status of a server at a given time interval, including server CPU utilization, memory usage, virtual memory exchange, IO Read and write situations. This command is I

#include #include #include #include # Include #include #include #include int main () {const Char *ip= "127.0.0.1"; int port=12345; struct SOCKADDR_IN address; Bzero (&address,sizeof (address)); Address.sin_family=af_inet;

Logical AND, and DOS batch usage exactly the sameThe following command will be executed only if the previous execution succeeds.This corresponds to a logical OR | | |, and only the previous execution failure is performed later.The shell also

Set special permissions)SUIDRole: Temporarily gives the owner of a user binary document permission (primarily for use by ordinary users for certain special commands)Grammar:chmod u+s file (increase s permission)chmod u-s file (minus s

Bzip2-k Services Compression Services files generate services.bz2 files while retaining source files are not deleted (compressed files)Tar-cjf shijiazhuang.tar.bz2 Shijiazhuang compress Shijizhuang directory and create shijiazhuang.tar.bz2 file

In the boot, due to the 80x86 features CS (Code Segment) This register is placed in 1, and IP (instruction Pointer) This register is all put 0, in other words, cs=ffff and ip=0000. At this point, the CPU is based on the value of CS and IP, to ffff0h

Use of anti-quote$ echo ' basename \ ' pwd\ ' # The command substitution based on the anti-quote is embeddable, but the inverted quotation marks of the embedded command need to escape the root $ d=$ (date) #除了反引号可以用于命令替换 with a backslash

1, Deb is the format of Ubuntu, Debian.RPM is the format of Redhat, Fedora, and SuSE.They are not universal (though they can be converted).Deb is a Debian-released packageUbuntu is a Debian-based release of all available. deb is the installation

Linux provides a rich help manual that you do not have to look for when you need to see the parameters of a command, as long as you have a man.The Linux Man Handbook has several chapters: Generation No. Representative contents

① Press the Power key, the computer hardware will read the BIOS to load hardware information (such as: CPU and Interface Device communication frequency, disk size and type, system time, peripheral bus, disk I/O, etc.) and the BIOS self-detection,②

1. Conceptual differences between the user and kernel statesWhat is the user state, what is the kernel state, these two basic concepts have been understood not very clearly, the root cause of the personal feel is because most of the time we write

One linux Command every day (1): more command, linux Command more The more command is similar to cat. The cat command displays the content of the entire file on the screen from top to bottom. More will display one page at a time to facilitate users

What should I do if the LinuxC program exits abnormally? -- core File helps you You must have encountered a program exit exception in Linux. The exit exception seems to have a magical magic, which will make you nervous suddenly. Don't be afraid.

Linux Process Management (c) Understanding the principles of process control is very important for understanding and modifying fio projects. "Fio is an I/O tool meant to be used both for benchmark and stress/hardware verification ."Process Unix

Use of the Linuxman SystemThe man system is a powerful help system in linux. It can provide almost all help information to system users and programmers. The help information mainly comes from the selfless contribution of many document maintainers

Failed to enable server-status. Enable server-status Recently, apache monitoring for monitoring has always encountered errors. After research, we found that: Next, we will give a brief introduction to it to prevent future use. 1. What is

UNIX advanced Environment programming (8) Process Environment (Process Environment)-Process startup and exit, memory layout, Environment Variable list, unixenvironment Before learning about process control, we need to understand the running

CentOS Study Notes-SCSI device hot swapping, centos-scsiCentOS Study Notes-SCSI device hot swapping In the running server, the server may not be allowed to be restarted due to business requirements. How can the newly added SCSI device (mainly hard

Linux-RedHat7/CentOS 7 forget the root password modification, redhat7centos 1. (a) when the grub boot loader boot option menu appears, click any keyboard restart and boot loader will be suspended. (B) Press 'e' to edit the option menu.(C) move