|The value of [ -a . ] is always true because -a is the and option of the test command. check out man test. [ -a . ] does not really make any sense. The . means the current directory so "and" current directory is always true.|
-a is typically used something like this:
if [ -r file1 -a -r file2 ]
Above if file1 has read permission "and" file2 has read permission, echo "Yes".
Let me know if you have any questions.