CSE 390A, Spring 2014 Assignment 1: Basic Unix Shell Commands
This assignment focuses on using the bash shell to execute common Unix commands. You will create and electronically turn in a file named homework1.txt that contains your answers to several questions below. Some of the questions are Unix commands you must figure out, and others are general questions about the particular Linux system you are using. Note: Unless otherwise specified, the answers to each question in this assignment can be found entirely using commands shown in the lecture notes from the first week. You may use other commands if you like, but you should constrain yourself to those from lecture or from the Linux Pocket Guide textbook. Ask the instructor if you are unsure whether a particular command is allowed.
Task 2:
(We are trying to persuade you that doing things in a terminal can sometimes be the easier way!)
If you did everything correctly, you should now have several files and directories within your hw1 directory, such as java/, website/, animals.txt, Burrot.java, numbers.txt, and verse1.txt .
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Task 3: Learn more about the Linux computer The following are questions about your Linux system for you to investigate and discover the answers. You should create a text file named homework1.txt and save it somewhere in your home directory, such as in your 390 folder. In this file, write your answers to the questions below. Your file should contain 5 answers total since there are 5 problems below. Most of the answers to the questions below can be found entirely using commands that you were shown in the week 1 slides. Any question that requires additional commands will have a label of "Self-Discovery". Remember that you can learn more about any command by typing:
man command
Each Linux system is different, so there is not one "correct" answer to every question. You will receive credit if your answer is plausible for a Linux system in general.
1. Try running each of the following commands on your Linux system, one at a time. (You don't need to turn in the output of the commands.) What is the last command doing? Describe what it does in one sentence. Remember that you can read more about a command and its parameters by looking at its man page.
ls ls -m ls -1 (in this case, the -1 is the number 1, not a lowercase L)
Answer:顯示檔案列表，每行只列出一個檔案
2. What is the full path of your home directory on this Linux machine? Run an appropriate command to find out.
(Note: You can select text on the Terminal window and copy/paste it into your text editor. The terminal program usually has a top menu bar where you can choose Edit Copy and Edit Paste.)
Answer:/home/zxy
3. What is the exact current date and time, as reported by this Linux machine? Run a command to find out.
Answer:2018年 05月 12日 星期六 21:30:49 CST
4. What other users have home directories on this Linux machine? (Hint: Find out what other user directories exist within the same parent folder as your home directory.) Provide a list of all such users in the format produced by the ls command. If there are more than 5 users, listing the last 5 is sufficient.
Answer:只存在一個使用者：zxy
5.(Self-Discovery) What release of Linux does this computer use?
To find out, run the Linux uname command, which outputs various information about the current system. It has various parameters that you can learn in its man page.
You are looking for the release of the kernel (the core) of the Linux OS, not the name of the "distribution" such as Fedora or Ubuntu. (Hint: On attu, the answer begins with 3.9)
Answer:4.4.0-116-generic
Task 4: Linux Bash shell commands For each of the numbered items below, determine a single bash shell statement that will perform the operation(s) requested. Each of your solutions must be a single one-line shell statement and should not use Linux's multi-statement joining operators such as |, &&, ||, and ; . (We haven't learned these yet, anyway.) Write these commands into your homework1.txt file. In other words, after completing this task, your homework1.txt file should now have 18 answers, including the 5 answers from Task 3. In your file, write the command that will perform the task described for each numbered item; don't write the output that the command produces. To test your commands, you should have unzipped hw1.zip into the current directory. Most of the questions below entirely use commands shown in the week 1 slides. Several questions require you to learn new parameters to those commands; find these out by looking at man pages or the Linux Pocket Guide.
1. List all files in the current directory, in "long listing format".
Answer: ls -l
2. List all files in the /var directory, in reverse alphabetical order.
Answer: cd /var | ls -r
3. Copy the file numbers.txt from the current directory to the java subdirectory.
Answer: cp numbers.txt java
4. Rename the file Burrot.java to Borat.java . (Hint: Renaming is done using the same command as moving.)
Answer: mv Burrot.java Borat.java
5. Delete the files diff.html and diff.css . (Hint: Many commands can accept more than one parameter.) Note that this must be done with a single command and not multiple commands.
Answer: rm diff.html diff.css
6. Print a text calendar for the month of July, 2014.
Answer: cal 07 2014
7. Set the file MyProgram.java to have a last-modified date of August 13, 2:37pm. (Hint: the man page for the proper command describes the timestamp 'STAMP' format to use. Look for this!) (Also note that Linux is case-sensitive when you are specifying file or directory names.)
Answer: touch -t 08131437 MyProgram.java
8. (Self-Discovery) You can use a * (asterisk) as a "wild-card" character to specify a group of files. For example, *foo means all files whose names end with foo , and foo* means all files whose names begin with foo . You can use a wildcard in the middle of a file name, such as foo*bar for all files that start with foo and end with bar .
List all web page files (files whose names end with the extension .html or .css) in the current directory. Note that the ls command can accept parameter(s) for what files you want it to list.
Answer: ls -a *.html *.css
9. Copy all the text files (files whose names end with .txt) from the current folder to the website subdirectory.
Answer: cp *.txt website
10. (Self-Discovery) The cat command outputs the contents of a file to the terminal. The less command outputs the contents of a file to the terminal, page by page, pausing for you to press a key.
Display the contents of the file MyProgram.java.
Answer: less MyProgram.java
11. Display the contents of all files whose names begin with verse and end with the extension .txt, such as verse1.txt and verse2.txt . (Write a single command that displays all their contents concatenated.)
Answer: more verse*.txt
12. (Self-Discovery) The head and tail commands output only the first or last few lines (respectively) of a file to the terminal.
Display only the last 5 lines of the file animals.txt from the current directory on the terminal.
Answer: tail -5 animals.txt
13. (Self-Discovery) The wc command outputs how many bytes, words, lines, etc. a file occupies. Display only the number of lines occupied by the file animals.txt .
Answer: cat animals.txt| wc -l