010-160: LPI Linux Essentials

whereis - answer-used to search for programs in restricted locations, such as binary file directories, libraries, and man directories. locate - answer-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 - answer-Updates the system managed database of filenames Displays current working directory - answer-pwd Change into the current user's home directory - answer-cd ~ cd $HOME Both of these do what Change to the parent directory of the current directory - answer-cd .. Change to the etc directory in the root (/) directory - answer-cd /etc Creates a hard link named '' for the file '' - answer-ln Creates a symbolic link named of - answer-ln -s touch - answer-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. - answer-touch -c Adds the content "Hey there!" to the specified file. - answer-echo "Hey there!" cat - answer-Displays the contents of a file Opens the vi editor for the file "sample". This will allow you to write text into a file. - answer-vi sample Will display the "sample" file's byte count - answer-wc -c sample Displays the number of characters in the "sample" file - answer-wc -m sample Display the number of lines in the "sample" file - answer-wc -l sample Display the word count of the "sample" file - answer-wc -w sample Extracts the first field of the "/etc/passwd" file - answer-cut -f 1 /etc/passwd Extract the first three characters from the "/etc/passwd" file - answer-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. - answer-cut -d ":" -f 3 /etc/shadow Search for all the rows containing the string "/home" in the "/etc/passwd" file - answer-grep /home /etc/passwd Display the number of lines containing the string "/bin" in the "/etc/passwd" file - answer-grep -c /bin /etc/passwd Display the details of the root user from the /etc/shadow file - answer-grep root /etc/shadow Search the /etc directory recursively for the string "wlan" - answer-grep -r wlan /etc Find all the files in the /etc directory having names that start with pass - answer-find /etc -name pass* List the files in the /etc directory with extensions conf (limit the search to one level) - answer-find /etc -maxdepth 1 -name *.conf List all the files on system with the permission set 640 (limit the search to two levels) - answer-find / -maxdepth 2 -perm 640 List the files in the var/cache directory owned by the root user (limit the search to two levels) - answer-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) - answer-find /root -group root find /root -gid 0 Sort the contents of the /etc/passwd file, and display it on the stdout - answer-sort /etc/passwd Numeric sort the third field of the /etc/passwd file and display it on the stdout - answer-cut -f 3 -d ":" /etc/passwd | sort -n Redirects the output of the echo $HOME command to a file named sample, overwriting its contents - answer-echo $HOME sample Appends the output of the pwd command to the sample file - answer-pwd sample Redirects the sample file as an input to the cat command. This will display the contents of the sample file. - answer-cat sample Appends only the standard error of the pwd;ech command to the sample file. - answer-pwd;ech 2 sample Overwrites the contents of the sample file with the standard output and error of the ls ~ /test command. - answer-ls ~ /test & sample Installs the traceroute program on Debian-based systems. - answer-apt-get install traceroute Whats it do and What distro typically uses it. Upgrades the system's software - answer-apt-get update apt-get upgrade Removes the traceroute package - answer-apt-get remove traceroute View all processes currently running - answer-ps Lists all the process that are currently running and are owned by the root user - answer-ps -u root Displays a dynamically updated list of processes running on the system - answer-top Displays the system's overall memory usage - answer-free Display a summary of services that are started via SysV scripts. /var/log/ contains messages that are logged during system boot. - answer-cat /var/log/ Installs the cups-daemon on the system. - answer-apt-get install cups-daemon List the files that log information related to the Linux printing system. - answer-ls /var/log/cups Displays the contents of the file that contains messages from daemons that do not have their own dedicated log file. File contains global log messages - answer-cat /var/log/syslog Displays the contents of the kernel ring buffer - answer-dmesg Opens the sample file using the vi editor. - answer-vi You would press i to enter the insert mode. You would press the esc key to exit insert mode. Yo