[: missing `]' +bash +shell scripts

 "=" sign requires a blank in front of it and after it. Otherwise, the bash only sees "something" within the brackets, and that is true (0), while "nothing" is false (1):

ex.

[ 5 = 6]

solution 

[ 5 = 6 ] 

Tutorials:

http://wiki.linuxquestions.org/wiki/Bash_tips

http://www.tldp.org/LDP/abs/html/

https://wiki.archlinux.org/index.php/Color_Bash_Prompt