010-160: LPI LINUX
ESSENTIALS
QUESTIONS &
ANSWERS
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
ESSENTIALS
QUESTIONS &
ANSWERS
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
