• From professional to personal

Asynchronously backup data before you lose it!
by Anooj Narvekar

There are limits to everything. My MacBook’s HDD has yet again got corrupted.
This means
* I have to reconfigure my ssh keys all authorized servers..
* Reconfigure my vimrc for all the shortcuts, alias’ and other things
* Personal documents which you must have forgotten to take backup on ur external storage device

Its time that i actually made use of dropbox.

What you can do is create symbolic links to files that you want to asynchronously backup as it gets changed

Something like this:

ln -s ~/.ssh/ ~/Dropbox/ssh

Well, if you guys have RAID arch set up then you can read up Jeff Atwood’s blog post which mentions his strategy.

Photo

September 15th

12:30
backup

Installing ruby-pg on MAC Snow Leopard
by Anooj Narvekar

Spent almost 2hrs in figuring how to get this done successfully. The error messages are so cryptic.

First of all, make sure u have postgres installed on your machine and the path to the postgres bin folder is in the $PATH enviroment variable. You can follow http://anooj.me/blog/?p=64 to set PATH.

To confirm, type pg_config in terminal to see if its in PATH. It should display the pg related configuration


anooj.n@dv-mac-anooj-n ~$ pg_config
BINDIR = /Library/PostgreSQL/8.4/bin
DOCDIR = /Library/PostgreSQL/8.4/doc/postgresql
HTMLDIR = /Library/PostgreSQL/8.4/doc/postgresql
INCLUDEDIR = /Library/PostgreSQL/8.4/include
PKGINCLUDEDIR = /Library/PostgreSQL/8.4/include/postgresql
INCLUDEDIR-SERVER = /Library/PostgreSQL/8.4/include/postgresql/server
LIBDIR = /Library/PostgreSQL/8.4/lib
PKGLIBDIR = /Library/PostgreSQL/8.4/lib/postgresql
LOCALEDIR = /Library/PostgreSQL/8.4/share/locale
MANDIR = /Library/PostgreSQL/8.4/share/man
SHAREDIR = /Library/PostgreSQL/8.4/share/postgresql
SYSCONFDIR = /Library/PostgreSQL/8.4/etc/postgresql
PGXS = /Library/PostgreSQL/8.4/lib/postgresql/pgxs/src/makefiles/pgxs.mk
CONFIGURE = '--prefix=/Users/buildfarm/pginstaller/server/staging/osx' '--with-openssl' '--with-perl' '--with-python' '--with-tcl' '--with-bonjour' '--with-pam' '--with-krb5' '--enable-thread-safety' '--with-libxml' '--with-ossp-uuid' '--with-includes=/usr/local/include/libxml2:/usr/local/include' '--docdir=/Users/buildfarm/pginstaller/server/staging/osx/doc/postgresql' '--with-libxslt' 'CFLAGS=-isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4 -headerpad_max_install_names -arch ppc -arch i386' 'LDFLAGS=-L/usr/local/lib'
CC = gcc -no-cpp-precomp
CPPFLAGS = -I/usr/include/libxml2 -I/usr/local/include/libxml2 -I/usr/local/include
CFLAGS = -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4 -headerpad_max_install_names -arch ppc -arch i386 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -fno-strict-aliasing -fwrapv
CFLAGS_SL =
LDFLAGS = -L/usr/local/lib -L/usr/lib
LDFLAGS_SL =
LIBS = -lpgport -lxslt -lxml2 -lpam -lssl -lcrypto -lkrb5 -lz -lreadline -lm
VERSION = PostgreSQL 8.4.8

Initially went straight and fired:


anooj.n@dv-mac-anooj-n ~$ sudo gem install ruby-pg
Building native extensions. This could take a while...
ERROR: Error installing ruby-pg:
ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb –with-pg-config=/Library/PostgreSQL/8.4/bin/pg_config
checking for main() in -lpq… yes
checking for libpq-fe.h… yes
checking for libpq/libpq-fs.h… yes
checking for PQconnectionUsedPassword()… no
checking for PQisthreadsafe()… no
checking for PQprepare()… no
checking for PQexecParams()… no
checking for PQescapeString()… no
checking for PQescapeStringConn()… no
checking for lo_create()… no
checking for pg_encoding_to_char()… no
checking for PQsetClientEncoding()… no
creating Makefile

make
gcc -I. -I. -I/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/universal-darwin10.0 -I. -DHAVE_LIBPQ_FE_H -DHAVE_LIBPQ_LIBPQ_FS_H -I/Library/PostgreSQL/8.4/include -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -fno-common -arch x86_64 -g -Os -pipe -fno-common -DENABLE_DTRACE -fno-common -pipe -fno-common -c compat.c
In file included from compat.c:16:
compat.h:38:2: error: #error PostgreSQL client version too old, requires 7.3 or later.
In file included from compat.c:16:
compat.h:69: error: conflicting types for ‘PQconnectionNeedsPassword’
/Library/PostgreSQL/8.4/include/libpq-fe.h:293: error: previous declaration of ‘PQconnectionNeedsPassword’ was here
compat.h:70: error: conflicting types for ‘PQconnectionUsedPassword’
/Library/PostgreSQL/8.4/include/libpq-fe.h:294: error: previous declaration of ‘PQconnectionUsedPassword’ was here
compat.h:123: error: redeclaration of enumerator ‘PQERRORS_TERSE’
/Library/PostgreSQL/8.4/include/libpq-fe.h:105: error: previous definition of ‘PQERRORS_TERSE’ was here
compat.h:124: error: redeclaration of enumerator ‘PQERRORS_DEFAULT’
/Library/PostgreSQL/8.4/include/libpq-fe.h:106: error: previous definition of ‘PQERRORS_DEFAULT’ was here
compat.h:126: error: redeclaration of enumerator ‘PQERRORS_VERBOSE’
/Library/PostgreSQL/8.4/include/libpq-fe.h:108: error: previous definition of ‘PQERRORS_VERBOSE’ was here
compat.h:126: error: conflicting types for ‘PGVerbosity’
/Library/PostgreSQL/8.4/include/libpq-fe.h:108: error: previous declaration of ‘PGVerbosity’ was here
compat.h:130: error: redeclaration of enumerator ‘PQTRANS_IDLE’
/Library/PostgreSQL/8.4/include/libpq-fe.h:96: error: previous definition of ‘PQTRANS_IDLE’ was here
compat.h:131: error: redeclaration of enumerator ‘PQTRANS_ACTIVE’
/Library/PostgreSQL/8.4/include/libpq-fe.h:97: error: previous definition of ‘PQTRANS_ACTIVE’ was here
compat.h:132: error: redeclaration of enumerator ‘PQTRANS_INTRANS’
/Library/PostgreSQL/8.4/include/libpq-fe.h:98: error: previous definition of ‘PQTRANS_INTRANS’ was here
compat.h:133: error: redeclaration of enumerator ‘PQTRANS_INERROR’
/Library/PostgreSQL/8.4/include/libpq-fe.h:99: error: previous definition of ‘PQTRANS_INERROR’ was here
compat.h:135: error: redeclaration of enumerator ‘PQTRANS_UNKNOWN’
/Library/PostgreSQL/8.4/include/libpq-fe.h:101: error: previous definition of ‘PQTRANS_UNKNOWN’ was here
compat.h:135: error: conflicting types for ‘PGTransactionStatusType’
/Library/PostgreSQL/8.4/include/libpq-fe.h:101: error: previous declaration of ‘PGTransactionStatusType’ was here
compat.h:140: error: conflicting types for ‘PQtransactionStatus’
/Library/PostgreSQL/8.4/include/libpq-fe.h:285: error: previous declaration of ‘PQtransactionStatus’ was here
compat.h:141: error: conflicting types for ‘PQparameterStatus’
/Library/PostgreSQL/8.4/include/libpq-fe.h:287: error: previous declaration of ‘PQparameterStatus’ was here
compat.h:155: error: conflicting types for ‘PQsetErrorVerbosity’
/Library/PostgreSQL/8.4/include/libpq-fe.h:309: error: previous declaration of ‘PQsetErrorVerbosity’ was here
compat.h:165:2: error: #error unsupported postgresql version, requires 7.3 or later.
compat.c: In function ‘PQsetClientEncoding’:
compat.c:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:35: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:43: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:49: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:55: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:61: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:67: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:73: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:79: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:85: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:93: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:102: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:109: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:115: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:125: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:131: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:137: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:143: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:151: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:159: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:167: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:173: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:179: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:185: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:191: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:197: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:203: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:209: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:218: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:225: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:268: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:327: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:374: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:453: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
compat.c:527: error: old-style parameter declarations in prototyped function definition
compat.c:527: error: expected ‘{’ at end of input
make: *** [compat.o] Error 1

Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/ruby-pg-0.7.9.2008.01.28 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/ruby-pg-0.7.9.2008.01.28/ext/gem_make.out

The error mentioned something like "PostgreSQL client version too old, requires 7.3 or later.". Don't get fooled by this.

Now try,


anooj.n@dv-mac-anooj-n ~$ sudo env ARCHFLAGS="-arch i386" gem install ruby-pg -- --with-pg-config=/Library/PostgreSQL/8.4/bin/pg_config
Password:
Building native extensions. This could take a while...
Successfully installed ruby-pg-0.7.9.2008.01.28
1 gem installed
Installing ri documentation for ruby-pg-0.7.9.2008.01.28...
Installing RDoc documentation for ruby-pg-0.7.9.2008.01.28...

PEACE. This worked for me.. :) Hopefully this should work for everyone.

UPDATE:
on running rake routes i started getting the following error:


anooj.n@dv-mac-anooj-n ~/workspace/pg/pgweb$ bundle exec rake routes
(in /Users/anooj.n/workspace/pg/pgweb)
rake aborted!
dlopen(/Library/Ruby/Gems/1.8/gems/pg-0.10.0/lib/pg_ext.bundle, 9): no suitable image found. Did find:
/Library/Ruby/Gems/1.8/gems/pg-0.10.0/lib/pg_ext.bundle: mach-o, but wrong architecture - /Library/Ruby/Gems/1.8/gems/pg-0.10.0/lib/pg_ext.bundle

To fix this, i had install postgres manually, i.e. download and compile the source manually which is pretty trivial.

had to change to install command also to


anooj.n@dv-mac-anooj-n ~$ sudo env ARCHFLAGS="-arch x86_64" gem install ruby-pg -- --with-pg-config=/Library/PostgreSQL/8.4/bin/pg_config

Photo

June 23rd

13:25
MAC

Fixing the preverifier build error for Mpowerplayer on Mac OS X
by Anooj

If you’re using the Mpowerlayer SDK for your J2ME development on Mac OS X, and you get the following ant build error:

$ ant
Buildfile: build.xml

compile:

preverify:
[exec] Error preverifying class java.lang.Class
[exec] VERIFIER ERROR java/lang/Class.newInstance0()Ljava/lang/Object;:
[exec] Illegal type in constant pool
[exec] Result: 1

package:

BUILD SUCCESSFUL
Total time: 1 second

Then you can fix it by changing the following entry in your build.xml:

<property name="java.classes.jar" value="/System/Library/Frameworks/JavaVM.framework/Classes/classes.jar" />

to

<property name="java.classes.jar" value="/System/Library/Frameworks/JavaVM.framework/Versions/1.4.2/Classes/classes.jar" />

This was the solution which i got after researching for quite sometime. However, this might have fixed issue for some, i was still facing the same issue.. :(

So after debugging for some more time, realized that
/System/Library/Frameworks/JavaVM.framework/Versions/1.4.2 was a symlink to the current jdk

dv-mac-anooj-n:Versions anooj$ ls -l
total 64
lrwxr-xr-x 1 root wheel 5 Jun 26 21:09 1.3 -> 1.3.1
drwxr-xr-x 3 root wheel 102 Jul 21 2009 1.3.1
lrwxr-xr-x 1 root wheel 10 Jun 26 21:09 1.4 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jun 26 21:09 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jun 26 21:09 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jun 26 21:09 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 5 Jun 26 21:09 1.6 -> 1.6.0
drwxr-xr-x 8 root wheel 272 Jun 26 21:11 1.6.0
drwxr-xr-x 9 root wheel 306 Jun 26 21:11 A
lrwxr-xr-x 1 root wheel 1 Jun 26 21:09 Current -> A
lrwxr-xr-x 1 root wheel 3 Jun 26 21:09 CurrentJDK -> 1.6

So now i just had to remove the symlink :

sudo rm 1.4.2

and paste 1.4.2 version folder here.. Issue resolved.

PS: i got 1.4.2 from my colleagues lappy.. Donno if apple allows you to download it.

Photo

August 27th

22:46
java

MAC

Mpowerplayer

preverifier

Initialize List the way Arrays are initialized
by Anooj

If you want a fixed size list, wherein you don’t want to add/remove elements into it then probably this trick will save some line of code:

Consider this:


List<Character> vowels = new ArrayList<Character>();
vowels.add('a');
vowels.add('e');
vowels.add('i');
vowels.add('o');
vowels.add('u');


This could have also be written as:


 List<Character> vowels = Arrays.asList('a', 'e', 'i', 'o', 'u');

Trying to add/remove elements from this list will result in an UnsupportedOperationException exception

Photo

August 10th

15:23
java

refactoring

Javascript refactoring
by Anooj

Might sound funny.. but ya.. i liked what i did today, so thought of sharing it..

So there was this combo box which needed to be pre-filled with currencies. This list of currencies was also loaded in a javascript array for other reasons.

The immediate refactoring was to use array to create options for the combo box. So i created a function which was called on body OnLoad event which would fill the select html element.

Was this required? This function will be called only once that too only onload of the page. Hmmm.. So my next refactoring was to remove the function and make javascript inline with my html body content.. Solved!

The advantages:

  • The function would make no sense, as in imagine a developer checking this code, he would be confused as to where all this function is used.
  • Debugging is easier. You don’t have to go to head to check your function, rather can just  write the js code where ur html element is.

The disadvantages(as mentioned by Kirit Pamar):

  • The javascript code is sent to the client each time a request is made to that page. This would be the case even if we called a method on body load. You could shove this script in a .js file and call the method on body load. This would improve the page load for each subsequent page request.
Photo

July 29th

16:07
javascript

refactoring

OpenX installation issue with postgres
by Anooj

OpenX official’s site says that it supports both Postgres as well as Mysql databases. But when i tried to install the OpenX, it only gave Mysql as the database option. Google’ing didn’t help much..
Banging head made me check the phpinfo() to check if my local php supports postgres. Luckily it was bang on.. It was not supporting Postgresql.

Fix:
Downloaded the latest installer for Mac OS X from here. Had to uncomment php module in the httpd.conf file located at /etc/apache2/httpd.conf so that php could be installed..

Photo

June 7th

21:51
Uncategorized

Get size of a required Schema in postgreSQL
by Anooj

Well, so my requirement this time was to get the size of all tables in a particular schema. HOW?

AFAIK, there was no direct way to fulfill my requirement. So wrote my own query..

SELECT pg_size_pretty(sum(pg_total_relation_size(‘archival.’||table_name))::bigint)
FROM information_schema.tables
WHERE table_schema=’archival’;

Where ‘archival’ is the schema name. Checkout the type-casting.
Short explanation: sum() returns int type, but pg_size_pretty() takes bigint as the param data type. Hence the type casting.

NB:- when copying the query, take care of the quotes.

Photo

January 19th

21:08
postgre

SQL

Getting postgres table and database size
by Anooj

Getting Database size:
SELECT pg_database_size(‘user’);
pg_database_size
——————
58241934

Oh.. thats in Bytes.. Make it nicer.. Get db size in MBs.

SELECT pg_size_pretty(pg_database_size(‘user_table’));
pg_size_pretty
—————-
60 MB

Getting Table size:

SELECT pg_size_pretty(pg_total_relation_size(‘user_table’));
pg_size_pretty
—————-
55 MB

Photo

January 19th

19:44
postgre

SQL

Uncategorized

Setting PATH environment variable in MAC
by Anooj

This probably most of the MAC users must be knowing, but still would like to document it.:

I had a pain myself figuring the way out. Following is the way(or should i say PATH??) to do it:

  • In your terminal, type cd /etc/paths.d/
  • touch mysql(this could be any name)
  • sudo vi mysql
  • [press i to insert] type in the path u want to append to the $PATH variable. In my case i wanted to set mysql’s path. So i had to type(copy paste rather) /usr/local/mysql/bin
  • [esc] :wq! to save the file.

U are done..

There is another way to set up $PATH, which is rather simple but wont be persisted with new sessions(new terminal or terminal tab).

To do so, in terminal u can just say export PATH=$PATH:<the path u want to append>

for ex., PATH=$PATH:/usr/local/mysql/bin

Photo

January 12th

23:51
MAC

TextMate Macro recording
by Anooj

Had to perform a series of regular expression search and replace actions. And had to do this on multiple files.. After doing it manually for sometime, got bored.. Cursed myself for violating DRY principle!

Well, to automate it, i used the TextMate’s bundled recording macro. Easy to use. Just start recording(Bundles->Macros->Start Recording). You can now replay it on multiple files.. Did my work.. Happy :)

Photo

December 21st

16:54
Uncategorized