SEARCH KEYWORD -- linux


  Check whether a remote server port is open on Linux

As a system administrator or network engineer or application developer, there is a need to check whether a port on remote server is open so that you can tell whether the service under check is running or not. In this post, we would cover a few methods to check whether a remote server port is open or not on Linux. telnet telnet is the most frequently used command on both Windows and Linux to check port. The simple usage for this command is  telnet [host] [port] When the port is open, the o...

   LINUX,TELNET,PORT,NC,NMAP     2017-12-23 11:45:20

  Configure a PHP web server on CentOS

Are you used to use cPanel or Plesk on VPS for your PHP website management? If for some reason you don't want to use them? What can you do? How do you maintain your website? How do you access Emails, use FTP to upload files or use phpMyAdmin to manage your databases? You may need to configure all these services yourself on a VPS without cPanel or Plesk or other similar apps.But to configure all these services on a Linux server is not an easy job. You may spend many nights but still fail to get s...

   Cron,Linux,CentOS,Email,FTP,MySQL     2012-07-08 06:01:56

  Use rsync to delete mass files quickly in Linux

Yesterday I encountered an issue to delete many log files in my Linux workstation, there were around 100,000 files to be deleted. These are log files and they grow very fast, and we need to delete them frequently. Usually we would use rm -rf * to delete these files, but we may need to wait for a relative long time if there are too many files. So we must adopt some unusual way. Fortunately, we can use rsync to delete mass files in one shot. 1. Install rsync yum install rsync 2. Create a new empty...

   rsync,delete file, demo     2012-11-13 10:44:50

  Linux Clock : CST,UTC and NTP setup

1. There is an option when you set up clock on installing Linux: system clock users UTC, so what does UTC mean? It's Universal Time Coordinated(UTC), there are two different times in GPS system: one is UTC , the other one is LT(Local Time). The difference between these two is just the timezone difference, UTC is the time in timezone 0. If the local time in Beijing is 8 o'clock in the morning, then UTC time is 0 o'clock, which is a 8 hour difference. 2. In Linux, when we use date to check the tim...

   Linux,Clock,UTC     2013-03-21 12:19:30

  Install Kubernetes with minikube and docker on Ubuntu

When someone just wants to play around Kubernetes on its local environment without accessing to Cloud provider resources, one can set Kubernetes up on local environment with minikube with single node mode. This post will provide a simple guideline on how to set up KUbernetes with minikube and docker on Ubuntu. Before all the steps can be started, you may need to first set up kubectl which is a command line tool to operate on Kubernetes resources. Post that, can ensure that docker is installed on...

   KUBERNETES,MINIKUBE,DOCKER,UBUNTU     2021-06-01 05:37:40

  Mount DD image on Linux

Yesterday, my Raspberry Pi running Arch Linux was not able to boot with error: Kernel Panic, not syncing: no init found. I spent a night on it, but could not find a working solution. The last option is easy: reinstall the system. That is really the last resort, for I do not want to re-setup everything I have done: samba server, Time Machine server, Xunlei Offline Downloader… Unable to mount the SD card The system does not boot, so I need to find a way to get into the file system to identi...

   LINUX,DD IMAGE     2014-06-24 07:49:14

  Embrace open source

In past few days, there are many tech news which are related to open source. For example, Microsoft enables Linux on its Windows Azure cloud, Facebook open sourced its C++ library Folly and Samsung joined Linux foundation. Now more and more big companies realize the power of open source and are willing to contribute to the open source community. It will benefit not only developers but also these big companies as well.By providing some open source libraries or projects, developer may reduce their...

   Open source,Microsoft,Samsung,Facebook,Linux     2012-06-06 05:37:59

  do {...} while (0) in macros

If you are a C programmer, you must be familiar with macros. They are powerful and can help you ease your work if used correctly. However, if you don't define macros carefully, they may bite you and drive you crazy. In many C programs, you may see a special macro definition which may seem not so straightforward. Here is one example: #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) There are many this kind of macros which uses do{...}while(0)...

   C,macro,C++     2014-01-23 07:16:13

  /dev/null and /dev/tty in Linux

In Linux, there are two special files /dev/null and /dev/tty. /dev/null will drop all the data written to it, i.e, when program writes data to this file, it means the program has completed the data write operation. But in  fact it does nothing, if you just want the status of a command but not the output of a command, this feature will be very useful. See below shell codes:     /> vi test_dev_null.sh        #!/bin/bash    if grep...

   Linux,/dev/null,/dev/tty     2013-03-04 02:23:23

  Linux的早期岁月

我的名字是 Lars Wirzenius，我曾经见证了Linux的起点。Linux现在是一个全球成功的操作系统，但它的开始却非常谦逊。这些是我对Linux最早的日子、它的创造以及它走向今天的记忆。 我于1988年秋季开始在赫尔辛基大学攻读计算机科学，并认识了 Linus Torvalds，他也是当年计算机科学专业的新生之一，而且和我一样说瑞典语。在那个学年的末尾，我们得到了一台Unix服务器的访问权限...

   LINUX,HISTORY,STORY     2023-05-18 07:23:18

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