[FW]linux - bash script environment variables

Reference:https://sites.google.com/site/tiger2000/home

$BASH_ENV	absolute path of startup file
$CDPATH	directories searched by cd
$FCEDIT	absolute path of history editor
$HISTCMD	the history number of the current command
$HISFILE	absolute path of history file
$HISTSIZE	number of remembered commands
$HOME	login directory
$IFS	token delimiters
$LINENO	current line number in shell script
$LINES	terminal height
$MAIL	absolute path of mailbox
$MAILCHECK	number of seconds to check mail
$OLDPWD	absolute path of previous directory
$OPTARG	option set by getopt
$OPTIND	option's ordinal position set by getopt
$OSTYPE	the OS on which bash is executing
$PATH	command search path
$PPID	process ID of parent
$PS1	primary prompt
$PS2	secondary prompt
$PWD	absolute path of current directory
$RANDOM	random integer
$REPLY	default variable for read
$SECONDS	number of seconds since shell started
$SHELL	absolute pathname of preferred shell
$TMOUT	seconds to log out after lack of use
$UID	user ID of the current user
$$	process ID of current shell
$?	exit status of most recent statement
$#	參數的數目
$*	代表所有參數
$!	PID of the most recently started backgroup job

[FW] Linux - shell script - detect multiple running instances of it self

Reference: http://giantdorks.org/alain/make-a-bash-script-quit-if-it-detects-multiple-running-instances-of-itself/

#!/bin/bash
if [ "$(pgrep -x $(basename $0))" != "$$" ]; then
 echo "Error: another instance of $(basename $0) is already running"
 exit 1
fi

Redmie - Useful plugin

1. redmine dashboard
1. Info: http://www.redmine.org/plugins/redmine-dashboard
2. Steps
1. cd /opt/bitnami/apps/redmine/htdocs/plugins
2. git clone https://github.com/jgraichen/redmine_dashboard.git
3. bundle install
2. redmine default assign
1. Info: https://github.com/giddie/redmine_default_assign
2. Steps
1. cd /opt/bitnami/apps/redmine/htdocs/plugins
2. git clone https://github.com/giddie/redmine_default_assign.git
3. rake db:migrate_plugins RAILS_ENV=production

VirtualBox - Waiting for network configuration issue (Missing eth0)

• if MAC address changed
• Remove /etc/udev/rules.d/70-persistent-net.rules file to make sure the new adapter to be eth0;
• Or update the /etc/network/interfaces for proper configuration for the new adapter (it maybe eth1, eth2 or ...)

[FW] Using gzip and gunzip with mysql to import/export backups

Exporting:

mysqldump -u user -p database | gzip > database.sql.gz

Importing:

gunzip < database.sql.gz | mysql -u user -p database

refer: http://failshell.io/mysql/using-gzip-and-gunzip-with-mysql-to-importexport-backups/

Mount cifs on Ubuntu Server (Microsoft Windows Shares)

1. sudo apt-get install cifs-utils
2. Temporary
2.1. mount -t cifs //XXX/XXX -o username=XXX,password=xxx /media/mnt
3. Permanent (for user MyAccount which uid is 1000)
3.1. Add a file .smbcredentials under /home/MyAccount with following informaiton
       username=XXX
       password=xxx
3.2 Add following into /etc/fstab
      //XXX/XXX /media/mnt cif uid=1000,credentials=/home/MyAccount/.smbcredentials 0 0
3.3. mount -a

refer: https://wiki.ubuntu.com/MountWindowsSharesPermanently

Update timezone on Ubuntu Server

1. Check Timezone
$ cat /etc/timezone
  Etc/UTC
2. sudo dpkg-reconfigure tzdata
  select Asia
  select Taipei

Refer: http://www.christopherirish.com/2012/03/21/how-to-set-the-timezone-on-ubuntu-server/