Which of the following statements is true?

A shell script is executed by:

Which is correct declaration(s) of a null variable 'a' in shell script?

What is the error in the following program?

What is the output of the following program?

What's the output assuming that the command line arguments are Unix shell scripting?

Which expression is correct?

If x=11 and y=6, then what is the exit status of the following expression?

Which statement is incorrect regarding if-then-fi?

Condition to check whether file with name 'xyz' is a regular file?

Output of the following shell script code?