What does the following command do?

# what is cal

Does Linux support wildcard characters, regular expressions and modifiers?

What does the pwd command do?

Which of the following is the intermediate between the hardware and the shell in the Linux operating system?

Which of the following is the parent process in Linux, which further has no parent?

How can you obtain a short description of the ls command?

System-wide values used by user and group creation utilities such as useradd and usergroup are kept in the file:

You use the SUSPEND character to suspend an already running process. Which signal does it send to the process?

What is the default maximum number of open files a user can have by default?

What command will free the page cache?

Which of the following options is true of the entry below? /dev/cdrom /cd iso9660 ro,user,noauto 0 0