Unix Commands

Question 1. Type the following commands and briefly explain the difference among the outputs. ($ Stands for UNIX prompt and you should not type it.)

1. $ls lists the files and folders in the current directory.
2. $echo * shows the names of all the files and folders in the current directory separated by a single space (Robbins 69).
3. $ls –l lists all files and folders in the current directory along with additional information like folder permissions and file owner.
4. $ls –al lists all files and folders in the current directory including hidden files.

Question 2. Type the following commands and briefly explain the subtle differences among the outputs.

1. $cat .bash_history outputs the contents of the bash history file to the command line (Shotts 73).
2. $more .bash_history presents the contents of the bash history file one screen at a time (without changing the contents) with support for forward navigation (Robbins 149).
3. $less .bash_history  presents the contents of the bash history file one screen at a time (without changing the contents) and with support for both forward and backward navigation (Robbins 116).
4. $tail -5 .bash_history returns the 5^th item from the end of the bash history file.
5.     $head .bash_history returns the first ten lines of the bash history file.

Question 3. ‘cd’ to /bin. ‘ls’ the directory. Type ‘man <program>’ for five programs in /bin. Which of the five has the most options? Which has the fewest?

 The $man <program> command displays program manual to the screen. This serves to offer helpful instructions to the user on how to use a given command option for a program. On my system the program with the most options is Netbeans, an integrated development environment. The program with the least options is cruncher, a handy wordlist generator (Shotts 42).

Question 4. Type ‘man ls’ at the shell prompt. Record the information in the following four fields of the manual page for this command:

The $man ls command displays a list of all items in a directory with a manual. The name displays the headings of the commands being displayed in the manual themselves. The synopsis offers a brief description of how the command should be used while the description gives the full text on how the command is used (Shotts 44).

Works Cited

Robbins, Arnold. UNIX In A Nutshell. Sebastopol, CA: O’Reilly, 2006. Print.

Shotts, William E. The Linux Command Line. San Francisco: No Starch Press, 2012. Print.