RHCSA Exam | Questions And Answers Latest {2024- 2025} A+ Graded | 100% Verified
In which language is Linux written? What does the language have to do with the success of Linux? -
More than 95 percent of the Linux operating system is written in the C programming language, and C is
portable because it is written in a higher-level, machine-independent language. (The C compiler is
written in C.)Because Linux is portable, it can be adapted (ported) to different machines and can meet
special requirements.
What is a shell? How does it work with the kernel? With the user? - In a textual environment, the shell—
the command interpreter—acts as an interface between you and the operating system. When you enter
a command on the screen, the shell interprets the command and calls the program you want.
Where on the disk should you put your /boot partition or the root (/) partition if you do not use a /boot
partition? - Put /boot at the beginning of the drive (partition 1) so that there is no issue
of Linux having to boot from a partition too far into the drive.
When might you specify an ext2 filesystem instead of ext4? - Use ext2 for partitions whose data does
not change often, such as /boot. The added overhead of the ext3 journal offers no benefit on these
filesystems.
Why would you place /var at the beginning of the disk? - The /var filesystem contains files that are
modified frequently. The beginning of the disk is near the outer edge and data can usually be accessed
faster from this location.
How can you keep other users from using write to communicate with you? Why would you want to? -
Give the command mesg n to keep ordinary users from writing to your termi- nal. You can take this
action when you do not want to be disturbed or when you are viewing something on your screen that
you do not want overwritten.
What happens when you use diff to compare two binary files that are not identical? (You can use gzip to
create the binary files.) Explain why the diff output for binary files is different from the diff output for
ASCII files. - Give the command mesg n to keep ordinary users from writing to your terminal. You can
take this action when you do not want to be disturbed or when you are viewing something on your
screen that you do not want overwritten.
, What is an inode? What happens to the inode when you move a file within a filesystem? - An inode is
the control structure for a file. If the two filenames have the same inode number, they share the same
control structure and are links to the same file.
Assume permissions on a file allow you to write to the file but not to delete it.
a. Give a command to empty the file without invoking an editor.
b. Explain how you might have permission to modify a file that you cannot delete. - Although it protects
you from overwriting a file using redirection, noclobber does not stop you from overwriting a file using
cp or mv. These utilities include the -i (interactive) option that helps protect you from this type of
mistake by verifying your intentions when you try to overwrite a file.
Why does the noclobber variable not protect you from overwriting an existing file with cp or mv? - The
noclobber variable keeps the shell from overwriting a file and does not work on utilities. Thus it keeps a
redirect symbol (>) from allowing the shell to overwrite a file (the shell redirects output) but has no
effect when you ask cp or mv to overwrite a file.
Discuss the client/server environment set up by the X Window System. How does the X server work? List
three X clients. Where is the client and where is the server when you log in on a local system? What is an
advantage of this setup? - When you start an X Window System session, you set up a client/server
environ- ment. One process, called the X server, displays a desktop and windows under X. Each
application program and utility that makes a request of the X server is a client of that server. Examples
of X clients include xterm, Compiz, gnome-calculator, and such general applications as word processing
and spreadsheet programs. A typical request from a client is to display an image or open a
window.Separating the physical control of the display (the server) from the processes needing access to
the display (the client) makes it possible to run the server on one computer and the client on another
computer.
When a user logs in, you would like the system to first check the local /etc/passwd file for a username
and then check NIS. How do you implement this strategy? - The /etc/nsswitch.conf file controls the
order in which sources are consulted to fulfill a request from the system. The following entry in this file
causes the system to check /etc/passwd first and NIS second:
passwd: files nis
Some older kernels contain a vulnerability that allows a local user to gain root privileges. Explain how
this kind of vulnerability negates the value of a chroot jail. - On Unix-like operating systems, such as
Linux, a chroot jail is the common expression used to describe a section of a filesystem that is sectioned
off for a particular user. On a web server, it is particularly useful for the security of shared hosting
accounts.
In which language is Linux written? What does the language have to do with the success of Linux? -
More than 95 percent of the Linux operating system is written in the C programming language, and C is
portable because it is written in a higher-level, machine-independent language. (The C compiler is
written in C.)Because Linux is portable, it can be adapted (ported) to different machines and can meet
special requirements.
What is a shell? How does it work with the kernel? With the user? - In a textual environment, the shell—
the command interpreter—acts as an interface between you and the operating system. When you enter
a command on the screen, the shell interprets the command and calls the program you want.
Where on the disk should you put your /boot partition or the root (/) partition if you do not use a /boot
partition? - Put /boot at the beginning of the drive (partition 1) so that there is no issue
of Linux having to boot from a partition too far into the drive.
When might you specify an ext2 filesystem instead of ext4? - Use ext2 for partitions whose data does
not change often, such as /boot. The added overhead of the ext3 journal offers no benefit on these
filesystems.
Why would you place /var at the beginning of the disk? - The /var filesystem contains files that are
modified frequently. The beginning of the disk is near the outer edge and data can usually be accessed
faster from this location.
How can you keep other users from using write to communicate with you? Why would you want to? -
Give the command mesg n to keep ordinary users from writing to your termi- nal. You can take this
action when you do not want to be disturbed or when you are viewing something on your screen that
you do not want overwritten.
What happens when you use diff to compare two binary files that are not identical? (You can use gzip to
create the binary files.) Explain why the diff output for binary files is different from the diff output for
ASCII files. - Give the command mesg n to keep ordinary users from writing to your terminal. You can
take this action when you do not want to be disturbed or when you are viewing something on your
screen that you do not want overwritten.
, What is an inode? What happens to the inode when you move a file within a filesystem? - An inode is
the control structure for a file. If the two filenames have the same inode number, they share the same
control structure and are links to the same file.
Assume permissions on a file allow you to write to the file but not to delete it.
a. Give a command to empty the file without invoking an editor.
b. Explain how you might have permission to modify a file that you cannot delete. - Although it protects
you from overwriting a file using redirection, noclobber does not stop you from overwriting a file using
cp or mv. These utilities include the -i (interactive) option that helps protect you from this type of
mistake by verifying your intentions when you try to overwrite a file.
Why does the noclobber variable not protect you from overwriting an existing file with cp or mv? - The
noclobber variable keeps the shell from overwriting a file and does not work on utilities. Thus it keeps a
redirect symbol (>) from allowing the shell to overwrite a file (the shell redirects output) but has no
effect when you ask cp or mv to overwrite a file.
Discuss the client/server environment set up by the X Window System. How does the X server work? List
three X clients. Where is the client and where is the server when you log in on a local system? What is an
advantage of this setup? - When you start an X Window System session, you set up a client/server
environ- ment. One process, called the X server, displays a desktop and windows under X. Each
application program and utility that makes a request of the X server is a client of that server. Examples
of X clients include xterm, Compiz, gnome-calculator, and such general applications as word processing
and spreadsheet programs. A typical request from a client is to display an image or open a
window.Separating the physical control of the display (the server) from the processes needing access to
the display (the client) makes it possible to run the server on one computer and the client on another
computer.
When a user logs in, you would like the system to first check the local /etc/passwd file for a username
and then check NIS. How do you implement this strategy? - The /etc/nsswitch.conf file controls the
order in which sources are consulted to fulfill a request from the system. The following entry in this file
causes the system to check /etc/passwd first and NIS second:
passwd: files nis
Some older kernels contain a vulnerability that allows a local user to gain root privileges. Explain how
this kind of vulnerability negates the value of a chroot jail. - On Unix-like operating systems, such as
Linux, a chroot jail is the common expression used to describe a section of a filesystem that is sectioned
off for a particular user. On a web server, it is particularly useful for the security of shared hosting
accounts.
