Ans: Normally, the newline character, which is generated by the ENTER or RETURN key, acts as the signpost. However, the semicolon and the ampersand characters can also serve as command terminators.

Ans: Parsing is the process of breaking up of a command line into words. This is made possible by using delimiters and spaces. In the event that tabs or multiple spaces are part of the command, these are eventually replaced by a single space

Ans: The root account is very important, and with abusive usage, can easily lead to system damage. That’s because safeguards that normally apply to user accounts are not applicable to the root account.

Ans: One important rule when naming files is that characters that have special meaning are not allowed, such as * / & and %. A directory, being a special type of file, follows the same naming convention as that of files. Letters and numbers are used, along with characters like underscore and dot characters.

Ans: Every process is uniquely identified by a process identifier. It is possible to view details and status regarding a process by using the ps command.

Ans: A super user is a special type user who has open access to all files and commands on a system. Note that the super user’s login is usually root, and is protected by a so-called root password.

Ans: Piping, represented by the pipe character “|”, is used to combine two or more commands together. The output of the first command serves as input the next command, and so on.

Ans: -l, which is normally used in listing command like ls, is used to show files in a long format, one file per line. Long format refers to additional information that is associated with the file, such as ownership, permissions, data and file size.

Ans:
- Telnet – used for remote login
- ping – an echo request for testing connectivity
- su – user switching command
- ftp – file transfer protocol used for copying files
- finger – information gathering command

Ans: A system call is part of the programming for the kernel. A library function is a program that is not part of the kernel but which is available to users of the system. UNIX commands, however, are stand-alone programs; they may incorporate both system calls and library functions in their programming.