SEARCH KEYWORD -- file system


  Create temp file in Bash using mktemp and trap

When working on Linux Bash, sometimes there is need to create temporary file. A common way of creating temp file on Linux is creating some file in /tmp directory. However there is security risk when creating temp file in /tmp directory. This post will show how to securely create temp file in Linux Bash. When creating file in /tmp directory, there are some security risks. This directory can be accessed by any user on the system, any user can write data into this directory as well. The files creat...

   LINUX,MKTEMP,TRAP,TEMP FILE     2019-12-30 23:28:23

  GoLang to build smaller executable file

Normally the executable file built with go is a bit large, it is always desired that a smaller executable file should be generated though. In this post, a couple of ways to reduce the size of the executable will be introduced. The end effect is that the executable file size would be much less than the normal generated one. The file which is built normally has below size. Mode LastWriteTime Length Name ---- ------------- ------ ---- -a---- 12/14...

   GOLANG,EXECUTABLE     2019-12-13 20:10:45

  Install flash plugin in Ubuntu

Step 1 : Get the libflashplayer.so file from Adobe offical websiteStep 2 : Extract the libflashplayer.so file to a folder Step 3 : Go tp the folder which sores the libflashplayer.so fileStep 4 : Run the following command in terminal             sudo ln -s libflashplayer.so /etc/alternatives/libflashplayer.soStep 5 : Start the Firefox and now can watch flash...

   Ubuntu,Flash,Install,Procedures,Plugin     2011-04-25 02:01:03

  How to reset root password in MySQL 8

The user password in MySQL is stored in the user table, the password reset is actually to change the value of record in this table. To change the password in case the password is forgotten, the idea is to bypass the authentication of MySQL and get into the system and update the record password value with SQL command. In MySQL 5, one can start MySQL service with --skip-grant-tables option, this option will tell the service to skip loading the grant tables when starting, hence the root user can lo...

   MYSQL,PASSWORD,MYSQL 8     2018-12-24 21:27:13

  Fix issue where no Java virtual machine found when launching Eclipse

In cases where a new Eclipse is installed or the location of the Java virtual machine binaries has been changed, you may face issue when launching Eclipse. The error would look like. And if you go to the location specified in the error message, there is no such path indeed.  And when clicks OK, the program just exits. The issue here is that it tries to find the java.exe binary and launch the program but it failed to locate it and hence exits. To fix this, you first need to ensure you have...

   ECLIPSE,JAVA,LAUNCH,ECLIPSE.INI     2019-09-07 05:31:27

  Apache Tomcat Installation and Configuration

When you want to install Apache Tomcat on Windows System. You may find that there are some tricky parts. Next I will elaborate the steps to install and configure Tomcat. If you want to install Tomcat as a service without GUI. You need to download the 32-bit Windows.zip from http://tomcat.apache.org/download-70.cgi. After downloading this zip file. You need to unzip this file to the directory which you want to put this software to. After unzipping, you can go to the bin directory and find t...

   TOMCAT 7,WINDOWS,APACHE,INSTALL,CONFIGUR     2011-04-10 14:17:21

  Differences between bashrc and profile in Linux

After login to a Linux system, the command console will show up with a prompt label such as # or ~, a shell command can be typed after this prompt and the system can execute the command thereafter. All these operations are handled by shell. Shell is a command language interpreter that executes commands read from the standard input device (keyboard) or from a file. There are different types of shells such as bash, ksh, csh etc. The most commonly used of them is bash and it's also the de...

   LINUX,PROFILE,BASH,BASHRC,.BASHRC,.PROFILE     2016-11-05 22:17:51

  Run executable jar on double click on Windows

Normally after installing Java, there will be an association between .jar and the javaw.exe. This enables the executable jar to be opened on double click. You can check the association by going to Control Panel -> Programs -> Default Programs -> Associate a file type or protocol with a program. The default program of a file type can be changed in this dialog. However sometimes there are cases where the file association for .jar may be altered after a third party application instal...

   JAVA,WINDOWS,JAR,EXECUTABLE JAR     2016-05-12 03:05:04

  How Kafka achieves high throughput low latency

Kafka is a message streaming system with high throughput and low latency. It is widely adopted in lots of big companies. A well configured Kafka cluster can achieve super high throughput with millions of concurrent writes. How Kafka can achieve this? This post will try to explain some technologies used by Kafka. Page cache + Disk sequential write Every time when Kafka receives a record, it will write it to disk file eventually. But if it writes to disk every time it receives a record, it would ...

   BIG DATA,KAFKA     2019-03-08 09:42:57

  A possible way to recover deleted files on Linux

Last week I was generating a MD5 sum for an virtual machine image on one OpenNebula server: # ls -l test.img -rw-r--r-- 1 root root 10486808576 Oct 12 02:21 test.img # md5sum test.img At the same time I was clearing the files on the server on another terminal and deleted the above image file mistakenly with : # rm test.img Since this image file is 10GB, it took some time to remove this file from the server, so I used the Ctrl+Z command to suspend the remove command. [1]+ Stopped ...

   Linux,File,Recovery     2013-11-26 07:03:37

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