Explanation: As we know that set command is used for assigning values to positional parameters, it also serves as debugging tool. For this purpose, we’ve to use -x option with it.

Explanation: Since x contains the value 10, and $ symbol is used with any variable for displaying its value. So $x will display 10. Hence the output will be x10$.

Explanation: x$x$ will be equal to x10$ and $x$x will be equal to 1010. Hence they are not equal.

Explanation: A shell script will stop running when we change its name if we’d used the positional parameter $0 in it as $0 contains the name of the script file.

Explanation: The exit status of a command is that particular value which is returned by the command to its parent. This value is stored in $?.

Explanation: The shell uses << symbol to read data from the same file containing the script. This is referred to as a here document. read command allows us to take input from the user to make the script interactive. && and || are logical operators which allow conditional execution. $* stores the complete set of positional parameters as a single string.

• check a file’s attributes

Explanation: shift statement is used for shifting the positional parameters to its immediate lower ones. Every time we use shift, the leftmost variable gets lost; s it should be saved in a variable before using shift.