This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Remember that 4 is just the minimum number of entries. Feel free to have more.
Represented by ~ this is your default working directory. This can be changed by using the usermod command as such: “usermod -d /path/to/new/homedir/ username”. you can navigate directly to your home directory from any where on the system by issuing the CD command with no arguments. ~/ can also be used as short hand when giving an absolute location.
line 1 is an example of a home directory, it is represented by ~ even though the actual location on the system looks more like line 2
lab46:~$ pwd /home/kreed11
using cd to move to home.
lab46:/etc/vim$ cd lab46:~$ pwd /home/kreed11
changing the home dir.
lab46:~$ pwd /home/kreed11 lab46:~$ usermod -d /home/kreed11/bin kreed11 lab46:~$ pwd /home/kreed11/bin
using ~ as an absolute location
lab46:/$ mv test ~/file/test lab46:/$ cd ~/file lab46:~/file$ ls test lab46:~/file$ pwd /home/kreed11/test
The directory you happen to be in. typically shown by the prompt. absolute path can be found by issuing pwd command.
prompt shows the current working directory to be /bin.
lab46:/bin$
absolute current working directory shown by pwd
lab46:~$ pwd /home/kreed11
Files that contain files. Can be created by the mkdir command and deleted by the rmdir and rm commands.
directories are donated by the “d” in the attributes field.
lab46:~$ ls -l total 12 drwxr-xr-x 3 kreed11 lab46 95 Sep 27 15:11 Downloads lrwxrwxrwx 1 kreed11 lab46 17 Aug 19 2010 Maildir -> /var/mail/kreed11 drwx------ 3 kreed11 lab46 142 Sep 29 15:21 bin drwx------ 2 kreed11 lab46 42 Sep 22 15:18 closet drwxr-x--x 2 kreed11 lab46 34 Sep 27 15:17 dl drwx------ 4 kreed11 lab46 39 Sep 29 14:50 irc -rw------- 1 kreed11 lab46 121 Sep 8 15:17 nohup.out drwx---r-x 3 kreed11 lab46 16 Sep 1 15:27 public_html drwx------ 2 kreed11 lab46 6 Sep 1 14:43 src -rw------- 1 kreed11 lab46 0 Apr 11 2008 times drwx------ 2 kreed11 lab46 4096 Sep 22 16:41 tmp -rw-r--r-- 1 kreed11 lab46 1659 Sep 27 15:00 wget-log lab46:~$ cd Downloads lab46:~/Downloads$ ls -l total 16132 drwx------ 4 kreed11 lab46 28 Aug 28 17:24 FileZilla3 -rw-r--r-- 1 kreed11 lab46 4828020 Sep 1 15:36 FileZilla_3.5.1_x86_64-linux-gnu.tar.bz2 -rw-r--r-- 1 kreed11 lab46 11689917 Sep 1 15:39 WinRARLinux.tar.gz lab46:~/Downloads$
creating and deleting a directory
lab46:~$ ls -l total 12 drwxr-xr-x 3 kreed11 lab46 95 Sep 27 15:11 Downloads lrwxrwxrwx 1 kreed11 lab46 17 Aug 19 2010 Maildir -> /var/mail/kreed11 drwx------ 3 kreed11 lab46 142 Sep 29 15:21 bin drwx------ 2 kreed11 lab46 42 Sep 22 15:18 closet drwxr-x--x 2 kreed11 lab46 34 Sep 27 15:17 dl drwx------ 4 kreed11 lab46 39 Sep 29 14:50 irc -rw------- 1 kreed11 lab46 121 Sep 8 15:17 nohup.out drwx---r-x 3 kreed11 lab46 16 Sep 1 15:27 public_html drwx------ 2 kreed11 lab46 6 Sep 1 14:43 src -rw------- 1 kreed11 lab46 0 Apr 11 2008 times drwx------ 2 kreed11 lab46 4096 Sep 22 16:41 tmp -rw-r--r-- 1 kreed11 lab46 1659 Sep 27 15:00 wget-log lab46:~$ rm -rf tmp lab46:~$ ls -l total 8 drwxr-xr-x 3 kreed11 lab46 95 Sep 27 15:11 Downloads lrwxrwxrwx 1 kreed11 lab46 17 Aug 19 2010 Maildir -> /var/mail/kreed11 drwx------ 3 kreed11 lab46 142 Sep 29 15:21 bin drwx------ 2 kreed11 lab46 42 Sep 22 15:18 closet drwxr-x--x 2 kreed11 lab46 34 Sep 27 15:17 dl drwx------ 4 kreed11 lab46 39 Sep 29 14:50 irc -rw------- 1 kreed11 lab46 121 Sep 8 15:17 nohup.out drwx---r-x 3 kreed11 lab46 16 Sep 1 15:27 public_html drwx------ 2 kreed11 lab46 6 Sep 1 14:43 src -rw------- 1 kreed11 lab46 0 Apr 11 2008 times -rw-r--r-- 1 kreed11 lab46 1659 Sep 27 15:00 wget-log lab46:~$ mkdir tmp lab46:~$ ls -l total 8 drwxr-xr-x 3 kreed11 lab46 95 Sep 27 15:11 Downloads lrwxrwxrwx 1 kreed11 lab46 17 Aug 19 2010 Maildir -> /var/mail/kreed11 drwx------ 3 kreed11 lab46 142 Sep 29 15:21 bin drwx------ 2 kreed11 lab46 42 Sep 22 15:18 closet drwxr-x--x 2 kreed11 lab46 34 Sep 27 15:17 dl drwx------ 4 kreed11 lab46 39 Sep 29 14:50 irc -rw------- 1 kreed11 lab46 121 Sep 8 15:17 nohup.out drwx---r-x 3 kreed11 lab46 16 Sep 1 15:27 public_html drwx------ 2 kreed11 lab46 6 Sep 1 14:43 src -rw------- 1 kreed11 lab46 0 Apr 11 2008 times drwx------ 2 kreed11 lab46 6 Sep 30 11:04 tmp -rw-r--r-- 1 kreed11 lab46 1659 Sep 27 15:00 wget-log lab46:~$
To list the files in your current directory, issue the ls command
lab46:~$ ls Downloads bin dl nohup.out src tmp Maildir closet irc public_html times wget-log lab46:~$
To copy a file use the cp command
lab46:~/tmp$ ls folder test lab46:~/tmp$ cp test folder/test lab46:~/tmp$ ls folder test lab46:~/tmp$ cd folder/ lab46:~/tmp/folder$ ls test lab46:~/tmp/folder$
Moving and renaming files is accomplished with the mv command
lab46:~/tmp$ ls folder test lab46:~/tmp$ mv test folder/test lab46:~/tmp$ ls folder lab46:~/tmp$ cd folder lab46:~/tmp/folder$ ls test lab46:~/tmp/folder$ mv test ~/tmp/testrename lab46:~/tmp/folder$ ls lab46:~/tmp/folder$ cd.. lab46:~/tmp$ ls folder testrename lab46:~/tmp$
To remove or delete files use the rm command
lab46:~/tmp$ ls -l total 0 drwx------ 2 kreed11 lab46 6 Sep 30 11:14 folder -rw------- 1 kreed11 lab46 0 Sep 30 11:10 testrename lab46:~/tmp$ rm testrename rm: remove regular empty file `testrename'? y lab46:~/tmp$ ls -l total 0 drwx------ 2 kreed11 lab46 6 Sep 30 11:14 folder lab46:~/tmp$
The creation of files can be accomplished by the touch and mkdir commadns and alternativly by saving a file from within a program such as nano
creating with commands:
lab46:~/tmp$ ls folder lab46:~/tmp$ touch test lab46:~/tmp$ ls folder test lab46:~/tmp$ mkdir folder2 lab46:~/tmp$ ls -l total 0 drwx------ 2 kreed11 lab46 6 Sep 30 11:14 folder drwx------ 2 kreed11 lab46 6 Sep 30 11:21 folder2 -rw------- 1 kreed11 lab46 0 Sep 30 11:20 test lab46:~/tmp$
Compression and Decompression is most commonly accomplished with the tar command.
lab46:~/tmp$ ls test test2 lab46:~/tmp$ tar -cvf compressed.tar test test2 test test2 lab46:~/tmp$ ls -l total 12 -rw------- 1 kreed11 lab46 10240 Sep 30 11:28 compressed.tar -rw------- 1 kreed11 lab46 0 Sep 30 11:20 test -rw------- 1 kreed11 lab46 0 Sep 30 11:28 test2 lab46:~/tmp$ rm -rf test lab46:~/tmp$ rm -rf test2 lab46:~/tmp$ ls -l total 12 -rw------- 1 kreed11 lab46 10240 Sep 30 11:28 compressed.tar lab46:~/tmp$ tar -xvf compressed.tar test test2 lab46:~/tmp$ ls -l total 12 -rw------- 1 kreed11 lab46 10240 Sep 30 11:28 compressed.tar -rw------- 1 kreed11 lab46 0 Sep 30 11:20 test -rw------- 1 kreed11 lab46 0 Sep 30 11:28 test2 lab46:~/tmp$
File permissions are useful for allowing or disallowing other users access to files. chmod is the command used for modifying permissions. File permissions can be viewed by reading the attributes column after issuing an ls -l command. the attributes section is 10 digits long, the first donates file type, the next three are owner permissions, the following three are group permissions and the last is everyone else permissions. each group of three is broken down in to read write and execute donated by a R, W, or X. each of the three groups can have R, W or X permissions seperate form the other so that if the last three is R– and the second is — then some one from the system can not see the file but the rest of the world can while neither can write or execute.
lab46:~/tmp$ ls -l total 0 -rw------- 1 kreed11 lab46 0 Sep 30 11:20 test -rw------- 1 kreed11 lab46 0 Sep 30 11:28 test2 lab46:~/tmp$ chmod 666 test lab46:~/tmp$ ls -l total 0 -rw-rw-rw- 1 kreed11 lab46 0 Sep 30 11:20 test -rw------- 1 kreed11 lab46 0 Sep 30 11:28 test2 lab46:~/tmp$
Tab completion allows the user to finish typing uniqe commands, directories and pritymuch any thing with out actually typing the entire word, command, etc. This accomplished by typing enough letters to find an unique match on the system then pressing TAB to fill in the rest.
lab46:~/tmp$ ls -l total 0 -rw-rw-rw- 1 kreed11 lab46 0 Sep 30 11:20 test -rw------- 1 kreed11 lab46 0 Sep 30 11:28 test2 -rw------- 1 kreed11 lab46 0 Sep 30 15:05 wikipedia lab46:~/tmp$ cat wi
press TAB
lab46:~/tmp$ cat wikipedia wikipedia test document lab46:~/tmp$
to Back-ground a process that is already running you will need to issue it a Ctrl-Z to suspend the process. Then the BG command to reanimate and run in the background. When executing a program or script, the & can be added to the end to set the process to run in the background from the start.
lab46:~/tmp$ cat
issue Ctrl-Z
^Z [1]+ Stopped cat lab46:~/tmp$ bg [1]+ cat & lab46:~/tmp$ ps USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND kreed11 12068 0.0 0.1 13664 2000 pts/59 SNs Sep22 0:00 /bin/bash kreed11 12072 0.0 0.5 42532 5368 pts/59 SN+ Sep22 1:06 irssi kreed11 25847 0.0 0.1 13648 2048 pts/51 SNs 14:43 0:00 -bash kreed11 30182 0.0 0.0 5860 532 pts/51 TN 15:14 0:00 cat kreed11 30223 0.0 0.0 8584 968 pts/51 RN+ 15:15 0:00 ps u lab46:~/tmp$
starting in the background with &
lab46:~/tmp$ cat & [1] 30859 lab46:~/tmp$ ps USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND kreed11 12068 0.0 0.1 13664 2000 pts/59 SNs Sep22 0:00 /bin/bash kreed11 12072 0.0 0.5 42532 5368 pts/59 SN+ Sep22 1:06 irssi kreed11 25847 0.0 0.1 13648 2056 pts/51 SNs 14:43 0:00 -bash kreed11 30646 0.0 0.0 5860 528 pts/51 TN 15:17 0:00 cat kreed11 30694 0.0 0.0 8584 972 pts/51 RN+ 15:18 0:00 ps u lab46:~/tmp$
State the course objective; define what that objective entails.
State the method you will use for measuring successful academic/intellectual achievement of this objective.
Follow your method and obtain a measurement. Document the results here.
Reflect upon your results of the measurement to ascertain your achievement of the particular course objective.
What is the limit of a numeric variable in bash?
Since bash is x86 based I would assume that the limit will be in the range of 32 bits or at least a power of 2.
set a value to 1 and increase the number of places it contains (12, 123, 1234, etc) intill bash does not return what was set.
lab46:~/tmp$ let a=1 lab46:~/tmp$ echo a a lab46:~/tmp$ echo $a 1 lab46:~/tmp$ let a=1234567890123456789 lab46:~/tmp$ echo $a 1234567890123456789 lab46:~/tmp$ let a=12345678901234567890 lab46:~/tmp$ echo $a -6101065172474983726 lab46:~/tmp$
Based on the data collected:
bash can only handle numbers up to 19 digits, why i have no idea…
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.
What is the question you'd like to pose for experimentation? State it here.
Collect information and resources (such as URLs of web resources), and comment on knowledge obtained that you think will provide useful background information to aid in performing the experiment.
Based on what you've read with respect to your original posed question, what do you think will be the result of your experiment (ie an educated guess based on the facts known). This is done before actually performing the experiment.
State your rationale.
How are you going to test your hypothesis? What is the structure of your experiment?
Perform your experiment, and collect/document the results here.
Based on the data collected:
What can you ascertain based on the experiment performed and data collected? Document your findings here; make a statement as to any discoveries you've made.