RHCSA EX200
In Bash what is an alias - Answer- User defined command:
[alias newcmd=oldcmd
what is an internal command - Answer- Runs as part of the shell itself
what is an external command - Answer- Exists as an executable file on the computer
what is the $Path - Answer- Defines a list of directories that search for a filename
when a user enters a command
Explain the following file descriptors
>
>>
2>
2>&1
< - Answer- > - Redirects stout - creates files or overwrites
>> - Redirects stout - creates or appends to file
2> - Redirect sterr
2>&1 - Redirects sterr to stout
< - Redirects stdin
what is ~.bash_history - Answer- Files that shows bash history commands
Explain the following environment configuration files
/etc/profile
/etc/bashrc
~/.bash_profile
~/.bashrc - Answer- /etc/profile - generic file processed by all users upon login
/etc/bashrc - This file is processed when subshells are started
~/.bash_profile - User specific variables that can be defined
~/.bashrc - User specific subvariables that can be defined
Explain the file system heirarchy
/
/bin
/boot
/dev
/etc
/home
/lib, /lib64
/media, /mnt
/proc
/opt
/root
/run
/sbin
, /srv
/sys
/tmp
/usr
/var - Answer- / - root directory, where the file system tree starts
/bin - Find executable programs that are needed to repair a system. Directory is
essential during boot
/boot - Contains all files/dirs that are needed to boot
/dev - Device files that are used for physical device access
/etc - Contains configuration files
/home - local home user directories
/lib, /lib64 - shared libraries used by /boot,/bin,/sbin
/media, /mnt - Directories used for mounting devices
/proc - Gives access to kernel information
/opt - used for optional packages
/root - root home directory
/run - processes since last boot. empties when powered off
/sbin - similar to bin. used by adminstrators
/sys - used as an interface to different hardware devices that are managed by the
kernel
/srv - used for data that may be used for services such as NFS,FTP,HTTP
/tmp - contains temp files
/usr - contain subdirectories for program files, libraries for program files, and
documentation about them
/var - contains files that may change in size dynamically such as log files, spool files
and mail boxes
What are hard links? - Answer- Inodes, access a files from a different location [ln
(source) (destination)]
what are soft links - Answer- allows you to access a file by filename and not inode [ln
-s (source) (destination)]
1. what is the tar utility?
2. how would you create an archive?
3. how would you extract an archive?
4. how would you extract one file from an archive? - Answer- 1. Utility used to create
archives
2. tar -cf [archivename.tar]
3. tar -xvf [archivename.tar]
4. tar-xvf [archivename.tar] [filename]
what is the console - Answer- The environment the use is looking at
what is the terminal - Answer- Opened in a console, provides access to the shell
List 3 commands to poweroff/reboot.
How would you force reset a machine? - Answer- 1. systemctl reboot / reboot
2. systemctl halt / halt
3. systemctl poweroff / poweroff
In Bash what is an alias - Answer- User defined command:
[alias newcmd=oldcmd
what is an internal command - Answer- Runs as part of the shell itself
what is an external command - Answer- Exists as an executable file on the computer
what is the $Path - Answer- Defines a list of directories that search for a filename
when a user enters a command
Explain the following file descriptors
>
>>
2>
2>&1
< - Answer- > - Redirects stout - creates files or overwrites
>> - Redirects stout - creates or appends to file
2> - Redirect sterr
2>&1 - Redirects sterr to stout
< - Redirects stdin
what is ~.bash_history - Answer- Files that shows bash history commands
Explain the following environment configuration files
/etc/profile
/etc/bashrc
~/.bash_profile
~/.bashrc - Answer- /etc/profile - generic file processed by all users upon login
/etc/bashrc - This file is processed when subshells are started
~/.bash_profile - User specific variables that can be defined
~/.bashrc - User specific subvariables that can be defined
Explain the file system heirarchy
/
/bin
/boot
/dev
/etc
/home
/lib, /lib64
/media, /mnt
/proc
/opt
/root
/run
/sbin
, /srv
/sys
/tmp
/usr
/var - Answer- / - root directory, where the file system tree starts
/bin - Find executable programs that are needed to repair a system. Directory is
essential during boot
/boot - Contains all files/dirs that are needed to boot
/dev - Device files that are used for physical device access
/etc - Contains configuration files
/home - local home user directories
/lib, /lib64 - shared libraries used by /boot,/bin,/sbin
/media, /mnt - Directories used for mounting devices
/proc - Gives access to kernel information
/opt - used for optional packages
/root - root home directory
/run - processes since last boot. empties when powered off
/sbin - similar to bin. used by adminstrators
/sys - used as an interface to different hardware devices that are managed by the
kernel
/srv - used for data that may be used for services such as NFS,FTP,HTTP
/tmp - contains temp files
/usr - contain subdirectories for program files, libraries for program files, and
documentation about them
/var - contains files that may change in size dynamically such as log files, spool files
and mail boxes
What are hard links? - Answer- Inodes, access a files from a different location [ln
(source) (destination)]
what are soft links - Answer- allows you to access a file by filename and not inode [ln
-s (source) (destination)]
1. what is the tar utility?
2. how would you create an archive?
3. how would you extract an archive?
4. how would you extract one file from an archive? - Answer- 1. Utility used to create
archives
2. tar -cf [archivename.tar]
3. tar -xvf [archivename.tar]
4. tar-xvf [archivename.tar] [filename]
what is the console - Answer- The environment the use is looking at
what is the terminal - Answer- Opened in a console, provides access to the shell
List 3 commands to poweroff/reboot.
How would you force reset a machine? - Answer- 1. systemctl reboot / reboot
2. systemctl halt / halt
3. systemctl poweroff / poweroff
