Which symbol is used with the cat command to create files?

The system call used to create a new process is

Which of the following is not a valid escape sequence in UNIX?

Which of the following is not a valid shell variable name?

Which statement matches an expression for more than one alternative?

The nice command in the C shell is a ______ command.

Which of the following is used for storing the number of positional parameters?

What does the command cat file1 file1 file1 display?

What does the -S option do in ls command? 

If the rmdir dir001 command fails, what could be the reason(s)?