Category Archives: Uncategorized

Assorted postgres queries

Get table sizes: SELECT relname AS objectname, relkind AS objecttype, reltuples AS “#entries”, pg_size_pretty(relpages::bigint*8*1024) AS size FROM pg_class WHERE relpages >= 8 ORDER BY relpages DESC;

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VirtualBox – Imporving usability on guest OS

GUEST OS: Centos 6.7 final HOST OS: Windows 7 Virtualbox version: 5.0.4 1yum install gcc kernel-devel kernel-headers dkms make bzip2 perl

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RedHat or CentOS 6 iptables adding an open port

iptables –line -vnL iptables -I INPUT 5 -p tcp –dport 80 -m state –state NEW,ESTABLISHED -j ACCEPT service iptables save

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Ant Junit debugging

Sometime we want to debug why ant build failed when executing a certain JUnit Make sure your ant junit task look like the following 1234<junit printsummary="withOutAndErr" haltonfailure="yes"> : : </junit> and not like 1234<junit printsummary="yes" haltonfailure="yes"> : : </junit>

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Using grep as highlighter

1$ grep –color -E ‘^|pattern1|pattern2′ file name

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TCL programming

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186#!/usr/bin/expect -f # TCL script. Beware whitespace matter! # To set multi-line comments do the following # set comment { #      your multi-line comment # } # ################################################### # ALL functions Start # ################################################### if {[llength $argv] == … Continue reading

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Simple unit test is bash file

Consider the following 3 files: 1. shellTestFramework.sh 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647#!/bin/bash # Copyright (c) Ronald Pringadi # Before each Test function setUpTest(){     #"Please overwrite this function on your unit test. Something that need to be done before each test"     … Continue reading

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Multithreading in Java using ThreadPoolExecutor

ThreadWorker is your custom class. 123456789try { ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(MAX_THREAD_SIZE); for (int i = 1; i Random randomGenerator = new Random(); executor.submit(new ThreadWorker("worker" + i, randomGenerator.nextInt(10))); LOG.info(i); } } catch (Exception e) { LOG.error("Hmm something is not right.", … Continue reading

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Getting the caller method details using Java

12345678910 public static String getCallerClassName() {         StackTraceElement[] stElements = Thread.currentThread().getStackTrace();         for (int i=1; i<stElements.length; i++) {             StackTraceElement ste = stElements[i];             if … Continue reading

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Compare File Permission Recussively on Linux Directories

Scan 12345678910111213141516171819202122#!/usr/bin/perl use File::Find; my $directory1 = ‘/root/rpmbuild/RPMSX’; my $directory2 = ‘/root/rpmbuild/RPMSX.bak’; find(\&hashfiles, $directory1); sub hashfiles {   my $file1 = $File::Find::name;   (my $file2 = $file1) =~ s/^$directory1/$directory2/;         return(0) if (! -f $file2) ;   … Continue reading

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