010-160: LPI LINUX ESSENTIALS QUESTIONS
Whereis - Answers -used to search for programs in restricted locations, such as binary
file directories, libraries, and man directories.
Locate - Answers -Searches the system managed database of filenames for files
containing the specified string in the filenames. (Search is much faster than the search
performed using the 'find' command)
Updatedb - Answers -Updates the system managed database of filenames
Displays current working directory - Answers -pwd
Change into the current user's home directory - Answers -cd ~
Cd $HOME
Both of these do what
Change to the parent directory of the current directory - Answers -cd ..
Change to the etc directory in the root (/) directory - Answers -cd /etc
Creates a hard link named 'format.txt' for the file 'fmt.txt' - Answers -ln fmt.txt format.txt
Creates a symbolic link named sym.txt of fmt.txt - Answers -ln -s fmt.txt sym.txt
Touch - Answers -Can be used to update the timestamp of a file or if that file doesn't
exist it will create a blank file with the specified name.
Will update the timestamp of the specified file if it exists. If it does not exist it will not
create a blank file. - Answers -touch -c file1.txt
Adds the content "Hey there!" to the specified file. - Answers -echo "Hey there!" >
sample.txt
Cat filename.txt - Answers -Displays the contents of a file
Opens the vi editor for the file "sample". This will allow you to write text into a file. -
Answers -vi sample
Will display the "sample" file's byte count - Answers -wc -c sample
Displays the number of characters in the "sample" file - Answers -wc -m sample
Display the number of lines in the "sample" file - Answers -wc -l sample
, Display the word count of the "sample" file - Answers -wc -w sample
Extracts the first field of the "/etc/passwd" file - Answers -cut -f 1 /etc/passwd
Extract the first three characters from the "/etc/passwd" file - Answers -cut -c 1, 2, 3
/etc/passwd
Extracts the third field from the "/etc/shadow" file and uses the : seperator. Since
"/etc/shadow" is a : (colon) seperated file, this command will display only the content of
the third field in the file. - Answers -cut -d ":" -f 3 /etc/shadow
Search for all the rows containing the string "/home" in the "/etc/passwd" file - Answers -
grep /home /etc/passwd
Display the number of lines containing the string "/bin" in the "/etc/passwd" file -
Answers -grep -c /bin /etc/passwd
Display the details of the root user from the /etc/shadow file - Answers -grep root
/etc/shadow
Search the /etc directory recursively for the string "wlan" - Answers -grep -r wlan /etc
Find all the files in the /etc directory having names that start with pass - Answers -find
/etc -name pass*
List the files in the /etc directory with extensions conf (limit the search to one level) -
Answers -find /etc -maxdepth 1 -name *.conf
List all the files on system with the permission set 640 (limit the search to two levels) -
Answers -find / -maxdepth 2 -perm 640
List the files in the var/cache directory owned by the root user (limit the search to two
levels) - Answers -find /var/cache -maxdepth 2 -user root
Find /var/cache -maxdepth 2 -uid 0
List all the files in the /root directory that belong to the root group (do not use shorthand
for specifying the directory) - Answers -find /root -group root
Find /root -gid 0
Sort the contents of the /etc/passwd file, and display it on the stdout - Answers -sort
/etc/passwd
Numeric sort the third field of the /etc/passwd file and display it on the stdout - Answers
-cut -f 3 -d ":" /etc/passwd | sort -n
Whereis - Answers -used to search for programs in restricted locations, such as binary
file directories, libraries, and man directories.
Locate - Answers -Searches the system managed database of filenames for files
containing the specified string in the filenames. (Search is much faster than the search
performed using the 'find' command)
Updatedb - Answers -Updates the system managed database of filenames
Displays current working directory - Answers -pwd
Change into the current user's home directory - Answers -cd ~
Cd $HOME
Both of these do what
Change to the parent directory of the current directory - Answers -cd ..
Change to the etc directory in the root (/) directory - Answers -cd /etc
Creates a hard link named 'format.txt' for the file 'fmt.txt' - Answers -ln fmt.txt format.txt
Creates a symbolic link named sym.txt of fmt.txt - Answers -ln -s fmt.txt sym.txt
Touch - Answers -Can be used to update the timestamp of a file or if that file doesn't
exist it will create a blank file with the specified name.
Will update the timestamp of the specified file if it exists. If it does not exist it will not
create a blank file. - Answers -touch -c file1.txt
Adds the content "Hey there!" to the specified file. - Answers -echo "Hey there!" >
sample.txt
Cat filename.txt - Answers -Displays the contents of a file
Opens the vi editor for the file "sample". This will allow you to write text into a file. -
Answers -vi sample
Will display the "sample" file's byte count - Answers -wc -c sample
Displays the number of characters in the "sample" file - Answers -wc -m sample
Display the number of lines in the "sample" file - Answers -wc -l sample
, Display the word count of the "sample" file - Answers -wc -w sample
Extracts the first field of the "/etc/passwd" file - Answers -cut -f 1 /etc/passwd
Extract the first three characters from the "/etc/passwd" file - Answers -cut -c 1, 2, 3
/etc/passwd
Extracts the third field from the "/etc/shadow" file and uses the : seperator. Since
"/etc/shadow" is a : (colon) seperated file, this command will display only the content of
the third field in the file. - Answers -cut -d ":" -f 3 /etc/shadow
Search for all the rows containing the string "/home" in the "/etc/passwd" file - Answers -
grep /home /etc/passwd
Display the number of lines containing the string "/bin" in the "/etc/passwd" file -
Answers -grep -c /bin /etc/passwd
Display the details of the root user from the /etc/shadow file - Answers -grep root
/etc/shadow
Search the /etc directory recursively for the string "wlan" - Answers -grep -r wlan /etc
Find all the files in the /etc directory having names that start with pass - Answers -find
/etc -name pass*
List the files in the /etc directory with extensions conf (limit the search to one level) -
Answers -find /etc -maxdepth 1 -name *.conf
List all the files on system with the permission set 640 (limit the search to two levels) -
Answers -find / -maxdepth 2 -perm 640
List the files in the var/cache directory owned by the root user (limit the search to two
levels) - Answers -find /var/cache -maxdepth 2 -user root
Find /var/cache -maxdepth 2 -uid 0
List all the files in the /root directory that belong to the root group (do not use shorthand
for specifying the directory) - Answers -find /root -group root
Find /root -gid 0
Sort the contents of the /etc/passwd file, and display it on the stdout - Answers -sort
/etc/passwd
Numeric sort the third field of the /etc/passwd file and display it on the stdout - Answers
-cut -f 3 -d ":" /etc/passwd | sort -n
