Saturday, December 24, 2011

[PostgreSQL][Mac] Modify root password (Forgot password)


  • sudo su postgres
  • supply your Mac password
  • modify /Library/PostgreSQL/9.x/data/pg_hba.conf
    • from local all all   md5
    • to local all all   trust
  • execute /Library/PostgreSQL/9.x/bin/pg_ctl restart -D /Library/PostgreSQL/9.x/data/
  • run psql
  • change postgres password
    • ALTER USER postgres WITH ENCRYPTED PASSWORD 'password';
  • modify pg_hba.conf back
  • restart again
Tested with PostgreSQL version 9.1 OSX Lion

Sunday, December 4, 2011

Learn some Ruby syntaxes from company source code

I think the fastest way to catch up Ruby and Rails idiomatic of my new company is to learn from it directly instead of learning from other available tutorials or books. Below is my note on this learning.

Rake

Exec shell command


  • use back-quote such as `ls`
  • return string from stdout
  • access Process object with $? such as $?.success
  • (not related to Ruby) `command 2>/dev/null` get rid of stderr

- string.chomp to remove new line in end of string

RSpec a lot of things on https://www.relishapp.com/rspec

Thursday, December 1, 2011

[MacOSX] How to modify enviroment.plist without any additional tools


  1. Convert enviroment.plist to XML format with plutil -convert xml1 environment.plist
  2. Edit it.
  3. Convert it back to binary format with plutil -convert binary1 environment.plist 

[RubyMine] invalid byte sequence in US-ASCII

I had this problem when I tried to bundle install. This causes from System Environment Variables which RubyMine is using is different from you shell and LANG is default to US-ASCII.

You can fix this (For 10.6+) by add LANG=en_US.UTF-8 to ~/.MacOSX/enviroment.plist

Please checkout How to modify enviroment.plist without any additional tools

Config number of file descriptors on Linux

Check file descriptor limit for a process. Vary depending on owner of the process $ cat /proc/{process-id}/limits Check current number of...