Author Archives: ronaldpringadi

Internet Explorer (IE) friendly table DOM manipulation

Posted on July 11, 2012 by ronaldpringadi

Occasionaly we can manipulate HTML DOM easily by accessing the innerHTML of an element. In IE however, the following elements’ innerHTML are read only: COL, COLGROUP, FRAMESET, HEAD, HTML, STYLE, TABLE, TBODY, TFOOT, THEAD, TITLE, TR. This code will fail … Continue reading →

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Preventing Another Instance of A Program Running in Linux

Posted on June 16, 2012 by ronaldpringadi

The code below is my solution for preventing a program from running more than once at the same time in Linux. The scenario: Consider if you have a cron job (jobA.sh) set to run at 6PM, 7PM, and 8PM. While … Continue reading →

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Extjs – Ext.apply

Posted on June 7, 2012 by ronaldpringadi

1234567891011121314151617181920console.clear(); var a = {     abc : 1,     def : 2 }; var b = {     abc : 1.1,     def : 2.2 }; var c = Ext.apply( a , b ); //Ext.apply … Continue reading →

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MySQL Backup and Restore – Using Command Line

Posted on March 11, 2012 by ronaldpringadi

Here’s how you back up a database from the command line. The first line is the backup, the second is the restore. These commands work on both Windows and Linux. On Windows you might want to add the MySQL bin … Continue reading →

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Browsing without ads on mobile browsers

Posted on February 17, 2012 by ronaldpringadi

This post used to recommend a now-defunct Android app called “Ad Block” that turned your phone into its own proxy server. The app is gone, the Play Store link is dead, and the proxy-based approach has been superseded several times … Continue reading →

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Benchmark How Long a Program Runs In Linux Using Bash

Posted on February 14, 2012 by ronaldpringadi

The following bash code might come in handy if you want to benchmark how long a program runs. The example assumes you want to pass two parameters along to the program. A timestamp is captured at the start and end … Continue reading →

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Auto Login Using SSH Public and Private Keys

Posted on February 13, 2012 by ronaldpringadi

2026 update: This post originally used ssh-keygen -t rsa. The current recommendation (e.g. GitHub’s SSH key guide) is Ed25519 — it produces shorter keys, is faster, and is considered more secure. Use RSA (4096-bit) only as a fallback for systems … Continue reading →

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Linux symlinks: creating, deleting, and the gotchas worth knowing

Posted on February 13, 2012 by ronaldpringadi

The basic command for creating a symbolic link (a “symlink” or “soft link”) to a folder or file is ln -s: 12345678ln -s /home/ronald/somefolder /home/ronald/newfolder # or if your current directory is already /home/ronald: cd /home/ronald ln -s somefolder newfolder … Continue reading →

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A Linux primer: identifying your distro and other commands that work everywhere

Posted on January 24, 2012 by ronaldpringadi

Here are a few commands you can use to find out which Linux distribution you’re on — pick whichever your system has: 1234567cat /etc/issue cat /proc/version dmesg | head -1 cat /etc/*-release Of those, cat /etc/*-release is the most reliable … Continue reading →

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How to Set up an FTP Server in Ubuntu Linux

Posted on January 18, 2012 by ronaldpringadi

Login to your Linux shell menu as root 12[root@locahost]# apt-get install vsftpd [root@locahost]# vim /etc/vsftpd.conf At VIM, 1st comment out anonymous_enable by adding a # sign at the beginning of the line # anonymous_enable=YES 2nd remove comment at local enable … Continue reading →

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