IT 244: Introduction to Linux/Unix

IT 244: Introduction to Linux/Unix
Class 6

Today's Topics

Reading Assignment

The reading assignment for this week is chapter 3 of Sobell, The Utilities.

You will find a list of all reading assignments here.

There is a link to this page on the class web page.

Homework 3

I have posted Homework 3 here.

As usual, it will be due next Sunday at 11:59 PM.

The is the first homework assignment that will require you to write a script.

Your script must meet certain requirements that I mentioned in the last class.

Let's review the requirements for homework scripts.

Tips and Examples

Copying and Pasting at the Command Line

You can have many ssh windows open ...
at the same time
Each of these windows runs inside an ssh client
These programs allow you to copy from one window ...
and paste into another
On my Mac I log into users3 ...
using the MacOS Terminal application ...
where I can copy text by selection it ...
holding down the Apple Command key ...
and pressing the C key
Similarly, if I have already copied something ...
I can paste it into the Terminal command line ...
by holding down the Apple Command key ...
and pressing the C key
In PuTTY simply selecting text will copy it
You do not have to use Control C
To paste into PuTTY simply click the left mouse button ...
or use select Paste from the Edit menu

A Space in the Wrong Place

I have often said that a mistake of a single character on the Unix command line ...
can cause a command to fail
I discovered a great example of this some semesters ago ...
while helping a student with a ex5.sh script

The problem involved two lines of the script

...
cd   /home/tsoro/course_files/it244_files
...
grep  -r  foo  .
...

The idea was to go to my it244_files directory
and search for lines that had "foo' in them ...
in all the files and subdirectories
The error was caused by putting a single space ...
in the wrong place in the cd command
Instead of typing the cd command given above ...

the student typed

cd   / home/tsoro/course_files/it244_files

Notice the space between the / and "home"
Because of this extra space ...
the cd command changed the directory to / ...
which is the top of the filesystem
The text after the space was ignored ...
because cd takes only one argument
The -r option to grep causes it to search files ...
in all subdirectories
This command will print all lines containing "foo" ...
in the entire filesystem
The only way to stop this is to use Control C

Finding Errors in a Script

Shell scripts are small programs
If a script contains a command that makes no sense ...
You will get an error when you run the script

The following script contains an error

$ cat go_home_bad.sh
# this script contains an error
cd /home/ghofman
pwd

When I run it I get

$ bash go_home_bad.sh
go_home_bad.sh: line 2: cd: /home/tsoro: No such file or directory
/home/tsoro/course_files/it244_file

Notice that even though there was an error on the first line ...
the script continued to run
In this case the error was a spelling mistake
The name of my home directory is tsoro ...
not ghofman
But what if after the error message appeared ...
there were several lines of output ...
which made it hard to see the error message?
The following script produces many lines of output ...

but it has the same error on the first line

$ cat go_home_bad_2.sh
# this script contains an error which is 
# hard to see in the output
cd /home/ghofman
ls -l

When I run this script it prints an error message ...
but that message is hard to see ...

because it scrools by fast off the top of the screen

$ bash go_home_bad_2.sh
go_home_bad_2.sh: line 3: cd: /home/ghofman: No such file or directory
-rw-rw-r-- 1 ghoffman faculty   51 Jun  8 11:54 numbers1.txt
-rw-rw-r-- 1 ghoffman faculty   51 Jun  8 10:55 numbers2.txt
-rw-rw-r-- 1 ghoffman faculty   50 Jun  8 10:55 numbers.txt
-rwxrwxr-x 1 ghoffman faculty   94 Jun  8 10:55 print_arg_numbers.sh
-rwxrwxr-x 1 ghoffman faculty  156 Jun  8 10:55 print_foo_bar.sh
-rwxrwxr-x 1 ghoffman faculty   71 Jun  8 10:55 print_foo.sh
-rwxrwxr-x 1 ghoffman faculty  132 Jun  8 10:55 print_positionals.sh
-rwxrwxr-x 1 ghoffman faculty  122 Jun  8 10:55 read_1.sh
-rwxrwxr-x 1 ghoffman faculty  141 Jun  8 10:55 read_2.sh
-rw-rw-r-- 1 ghoffman faculty 1214 Jun  9 10:35 red_sox.txt
-rwxrwxr-x 1 ghoffman faculty  260 Jun  8 10:55 repeat.sh
....

There is a trick that you can use ...

to see only the error messages

$ bash go_home_bad_2.sh > /dev/null
go_home_bad_2.sh: line 3: cd: /home/ghofman: No such file or directory

When I follow the command with
```
> /dev/null
```
Unix throws away everything except the error messages
You'll see why this works when we discuss redirection ...
in a future class

Review

`echo` - Print Text to the Terminal

echo prints text to the screen
```
$ echo Hello
Hello
```
You can use echo to print the value of a system variable ...
if your precede the variable name with a $
```
$ echo $SHELL
/bin/bash
```

`hostname` - Print the Name of Your Host Machine

hostname prints the network name of the machine that you have logged on to
```
$ hostname
itserver6
```
When used with the -i option ...
hostname will print the IP address of the machine
```
hostname -i
192.168.107.136
```

Pagers - View a File One Screen at a Time

Pagers are programs that display the contents of a file ...
one screenful at a time
The two pagers that Unix supplies are more and less
Hitting the Space bar advances to the next screen
Hitting the Enter or Return key takes you down one line
less, just to be confusing, has more features than more

Pathname Completion

When typing a long file name it is easy to make a mistake
To make life easier, Unix provides a feature called pathname completion
You type a few characters ...
then hit the Tab key ...
and Unix will try to supply the rest
If there is only one file or directory that matches ...
Unix will fill in the rest of the name
If there is more than one match ...
Unix will supply as much as it can and then beep
If you hit Tab again it will show you the possible matches
If there is no match, it will also beep

`grep` - Finding Strings inside Files

grep is used to find all lines in a file ...
that contain a certain string
grep takes two arguments
- The string you are searching for
- The file or files in which to search
grep has the following format
```
grep STRING FILE [FILE ...]
```
To run grep on the files in a directory ...
use the -r (recursive) option
grep -r will search through all files in a directory ...
and in all subdirectories
grep, like Unix, is case sensitive
It thinks of "foo" and "FOO" as two different strings
To have grep ignore case ...
run it with the -i option
To have grep find all lines that do not match a string ...
run it with the -v option

`head` - View the Top of a File

head prints the first 10 lines of any file
If you want a different number of lines ...
follow head with a dash, -, and a number
```
head -20 foo.txt
```

`tail` - View the Bottom of a File

tail prints the last 10 lines of any file
If you want a different number of lines ...
follow tail with a dash, -, and a number
```
tail -5 foo.txt
```

`sort` - Print a File in Sorted Order

sort prints all the lines in a file ...
in sorted order
sort does not change the file
To sort in reverse order use the -r option
sort, by default, sorts in alphabetical order
This is a problem when the first characters on a line are numbers
That's because 11 will sort before 2
To sort in numerical order use sort -n
To sort in reverse numerical order use sort -nr

New Material

`uniq` - Eliminate Duplicate Lines

uniq prints the lines in a file

removing adjacent identical lines

$ cat numbers2.txt 
4
5
6
7
8
9
10
11
11
11
12
13
14
15
16
17
18
19
20
	
$ uniq numbers2.txt 
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Note, the duplicate lines must be adjacent ...
for uniq to work
For this reason, it's good to use sort along with uniq
uniq -i ignores case when looking for duplicate lines

`diff` - Differences between Files

diff compares two files ...
and displays the lines that are different

The default output format of diff is confusing

$ cat numbers1.txt 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
	
$ cat numbers2.txt 
4
5
6
7
8
9
10
11
11
11
12
13
14
15
16
17
18
19
20
	
$ diff  numbers1.txt  numbers2.txt 
1,3d0
< 1
< 2
< 3
10a8,9
> 11
> 11

diff was created for use with the Unix patch utility ...
which creates a new version of a file ...
from the changes given by diff
This output was never meant to be read by people

The most readable output is obtained by using the -y option

$ diff  -y  numbers1.txt numbers2.txt 
1                                 <
2                                 <
3                                 <
4                               4
5                               5
6                               6
7                               7
8                               8
9                               9
10                              10
                                >  11
                                >  11
11                              11
12                              12
13                              13
14                              14
15                              15
16                              16
17                              17
18                              18
19                              19
20                              20

diff -i ignores case when looking for differences.

The Shell Prompt

In the last class I mentioned shell variables
We'll talk a lot more about them in a few weeks
But right now I'd like to say a few words about one particular variable
PS1 is the variable that determines your Unix prompt
This variable can be customized in many ways ...
to provide all sorts of useful information
By default PS1 tells you three things
- Your Unix username
- The machine to which you are connected
- The location of your current directory
Some of you may have noticed that my prompt ...
looks different from yours
That's because I have customized the value of PS1 ...
for my Unix account
But before I did this, my prompt looked like this
```
tsoro@vm74:~/it244/work$
```
The characters before the @ show my Unix username ...
the characters between @ and : are the hostname
of the machine I am using ...
and the characters from : to $ show my current directory
The ~ indicates my home directory
We'll talk more about this in a future class
So when I got this prompt, I was in the directory
```
/home/tsoro/it244/work
```
If you look carefully at your prompt ...
you can always see where you are in the Unix filesystem

`file` - Show the File Type

The file utility takes an argument of one or more files ...

and shows the type of each

$ file *
bin:                 directory
cars.txt:            ASCII text
cmds:                directory
dead.letter:         ASCII news text
downloads:           directory
exercises_it244:     directory
f11_it244_class_web: directory
hw_it244:            directory
it244:               symbolic link to `/courses/it244/s12/ghoffman/'
java:                directory
...

You can also run file on individual files

$ file break.sh
break.sh: Bourne-Again shell script, ASCII text executable

$ file make_upper.py 
make_upper.py: Python script, ASCII text executable

$ file index.html 
index.html: HTML document, ASCII text

Pipes - Stringing Programs Together

Pipes are one of the most powerful features of Unix
A pipe takes the output of one Unix command ...
and feeds it into the input of another
Using pipes you can string programs together ...
so they can perform a task ...
that none of them could do separately
A pipe consists of two or more Unix commands ...
each one separated from the one that came before by |
Using a pipe, we can build up a string of commands ...
to get exactly what we want
Let's say we want to find all Red Sox wins against the Rays ...
sorted in reverse order by date ...

from the following file

$ cat red_sox.txt 
2011-07-02      Red Sox @  Astros       Win 7-5
2011-07-03      Red Sox @  Astros       Win 2-1
2011-07-04      Red Sox vs Blue Jays    Loss 7-9
2011-07-05      Red Sox vs Blue Jays    Win 3-2
2011-07-06      Red Sox vs Blue Jays    Win 6-4
2011-07-07      Red Sox vs Orioles      Win 10-4
2011-07-08      Red Sox vs Orioles      Win 10-3
2011-07-09      Red Sox vs Orioles      Win 4-0
2011-07-10      Red Sox vs Orioles      Win 8-6
2011-07-15      Red Sox @  Rays         Loss 6-9
2011-07-16      Red Sox @  Rays         Win 9-5
2011-07-17      Red Sox @  Rays         Win 1-0
2011-07-18      Red Sox @  Orioles      Win 15-10
2011-07-19      Red Sox @  Orioles      Loss 2-6
2011-07-20      Red Sox @  Orioles      Win 4-0
2011-07-22      Red Sox vs Mariners     Win 7-4
2011-07-23      Red Sox vs Mariners     Win 3-1
2011-07-24      Red Sox vs Mariners     Win 12-8
2011-07-25      Red Sox vs Royals       Loss 1-3
2011-07-26      Red Sox vs Royals       Win 13-9
2011-07-27      Red Sox vs Royals       Win 12-5
2011-07-28      Red Sox vs Royals       Loss 3-4
2011-07-29      Red Sox @  White Sox    Loss 1-3
2011-07-30      Red Sox @  White Sox    Win 10-2
2011-07-31      Red Sox @  White Sox    Win 5-3

First let's find all games against the Rays

$ grep Rays red_sox.txt
2011-07-15      Red Sox @  Rays         Loss 6-9
2011-07-16      Red Sox @  Rays         Win 9-5
2011-07-17      Red Sox @  Rays         Win 1-0

Now let's feed this into another command that selects the games the Sox won

$ grep Rays red_sox.txt | grep Win
2011-07-16      Red Sox @  Rays         Win 9-5
2011-07-17      Red Sox @  Rays         Win 1-0

Now we can use sort to get the results in the order we want

$ grep Rays red_sox.txt | grep Win | sort -r
2011-07-17      Red Sox @  Rays         Win 1-0
2011-07-16      Red Sox @  Rays         Win 9-5

The Unix tool philosophy is simple programs doing one thing well
Pipes are an essential element in making this philosophy work
As we progress through this course ...
you will have many opportunities to use pipes

`date` - Get the Date and Time

date displays the time and date
```
$ date
Tue Aug  7 20:02:48 EDT 2012
```
You can change the way the date is displayed ...

by following date with a + and a format string

$ date +"%Y-%m-%d %r"
2012-08-07 08:19:44 PM

The format string consists mostly of pairs of character pairs ...
the first character of which is a %
In the string above, %Y stands for the four digit year
To get more information on the various formatting options use
```
info date
```

Now move the cursor down to the line that reads

* Date conversion specifiers::     %[aAbBcCdDeFgGhjmuUVwWxyY]

Then hit the Enter key

Text File Conversion Programs

Text files on Unix differ from those on Windows machines ...
by the characters used to mark the end of a line
There are two packages that provide software ...
to convert between these two formats
- tofrodos
- unix2dos
We won't be using either of them in this course ...
but you should know about them
The tofrodos package provides todos ...
to convert Unix files to Windows format
The same package has fromdos to go the other way
The unix2dos package uses unix2dos ...
to convert Unix text files to Windows text
It also provides dos2unix to go the other way
You will not be expected to know this ...
for a quiz or exam

Compressing Files with `bzip2`

On the Internet there are many files ...
which are free for the taking
Many of these files are huge ...
and copying them to a machine can take a long time
To speed up the process, big files are usually compressed
Compression utilities are used to do this
bzip2 is one such utility
It achieves the highest compression ratio ...
of all common compression utilities
You run bzip2 like this
```
bzip2 FILENAME
```
bzip2 compresses the file ...
creating a new file with the extension .bz2 ...
and deletes the original file
If you need to keep the original file ...
run bzip2 with the -k (for keep) option
To decompress a file created by bzip2 ...
use bunzip2 like this
```
bunzip2 FILENAME.bz2
```
bunzip2 decompresses the .bz2 file ...
and create a new file ...
with the .bz2 extension removed
The compressed file is also deleted
A file that bunzip2 has compressed is unreadable
If you want to look at the contents of a .bz2 compressed file ...
without uncompressing it ...
use bzcat
bzcat, will print the uncompressed contents of a file to the screen
bzcat does not alter the original, compressed file

`gzip` - the GNU Compression Utility

The GNU project created gzip to compress files
It is older, and less efficient, than bzip2
But many open source packages are compressed with this program
It is similar in operation to bzip2
The compressed files gzip creates have a .gz extension
To show the contents of a file without converting it ...
use zcat
To decompress a gzipped file, use gunzip
These utilities have nothing to do with the zip and unzip programs ...
that are frequently used on Wintel machines

`tar` - Packaging Files for Transfer or Storage

Most software packages consist of many files
But to distribute the package efficiently ...
you really want to turn these many files ...
into a single file
This also needs to be done when backing up a directory
tar (tape archive) is the Unix utility used for this purpose
tar does not compress files
it stuffs multiple files into a single file ...
often called a tarball
tar is usually used along with a compression program
First you run tar to create a single file ...
then you run another utility to compress the file
You also use tar to unpack the files
You run tar with different options ...
to pack, or unpack, a set of files
To "tar up" a set of files, run
```
tar cvf ARCHIVE_NAME.tar DIRECTORY_NAME
```
The options stand for create, verbose, file
The .tar extension is a convention
Though you do not have to use this extension ...
you would be foolish not to
To see the files contained in a tar file ...
without unpacking them use
```
tar -tvf ARCHIVE_FILE
```
To unpack a tarball use
```
tar -xvf ARCHIVE_FILE
```
The -x option stands for extract
Normally, you create a tarball ...
and then run a compression program on the archive file
If bzip2 is used for compression ...
the new file will often have a .tar.bz2 or .tbz extension
If gzip is used ...
the extensions usually are .tar.gz, .tgz,
or sometimes simply .gz
Again, these are simply conventions
But don't violate these conventions ...
unless you have a very good reason
Life is complicated enough as it is

`which` - Finding a Program File

Unix commands are programs ...
which exist as binary files ...
containing numeric codes that the computer's processor understands
that are located somewhere in the filesystem
You can use the Unix utility which ...
to find the exact location of any binary program file
To find the location of the tar program file we would run
```
$ which tar
/bin/tar
```
which shows that the executable file for tar ...
is located in the /bin directory
which uses the PATH system variable ...
to find the location of the file
We'll discuss PATH in a future class

`whereis` - Finding Files Used by a Program

whereis is another program that can be used to locate program files
whereis takes an approach different from that of which
Every Unix or Linux system has certain standard places ...
where it stores programs and the files they use
whereis searches these locations
It returns a list of all files associated with a program
The list gives the name of the file as well as it's location
When we run whereis on tar

we get more information than which returned

$ whereis tar
tar: /bin/tar /usr/include/tar.h /usr/share/man/man1/tar.1.gz

The first entry is the executable file /bin/tar
The second entry is a header file /usr/include/tar.h
The program needs the header file to get certain information
The third entry is the file that man uses ...
to provide information about tar
A word of caution about using which and whereis
Some commands are actually built into the shell itself
These command are called built-ins ...
and we will talk about them in a future class
If you run which or whereis on these programs ...
you will get nothing back
```
$ which cd
$
```

`locate` - Search for Any File

which and whereis only work on programs
locate can be used to find any file
You don't need to know the full name of a file to use locate

locate will search on a partial file name

$ locate foot
/etc/update-motd.d/99-footer
/usr/share/doc/java-common/debian-java-faq/footnotes.html
/usr/share/emacs/23.3/lisp/mail/footnote.elc
/usr/share/emacs/23.3/lisp/org/org-footnote.elc
/usr/share/libparse-debianchangelog-perl/footer.tmpl
/usr/share/xml-core/catalog.footer
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/Kconfig
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/Makefile
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/Makefile.boot
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/debug-macro.S
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/entry-macro.S
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/hardware.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/io.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/irqs.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/isa-dma.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/memory.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/system.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/timex.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/uncompress.h
/usr/src/linux-headers-3.0.0-12/arch/arm/mach-footbridge/include/mach/vmalloc.h

locate does not actually search the file system itself
That would take too long
Instead it uses a database of all files on the system
This database is created by another program updatedb
updatedb is usually run automatically in the background to update the database
It will not work on any other machine

`find` - Search for Files Using Different Criteria

The most powerful Linux/Unix command for finding files is find
Unfortunately, it's power makes it harder to use that locate
find can be used to search for a file based on many different things such as
- The name of the file
- The last time the file was used
- The last time the file was changed
- The access permissions on the file
An in-depth discussion of find is beyond the scope of this course
The simplest way to use find is searching for files by name
You do this using the following format
```
find DIRECTORY -name FILENAME
```

Here is an example

$ find  /home/tsoro  -name red_sox.txt
/home/tsoro/course_files/it244_files/red_sox.txt
/home/tsoro/course_files/it441_files/red_sox.txt

Unlike locate, find will not accept a partial file name
```
$ find  /home/tsoro  -name red

$
```
You can get the effect of searching on a part of a filename ...
by using the * character
But since * has special meaning on the command line ...

you have to escape it

$ find /home/tsoro -name memo.\*
/home/tsoro/memo.bak
/home/tsoro/memo.txt
/home/tsoro/tmp/memo.bak
/home/tsoro/tmp/memo.txt
/home/tsoro/tmp/memo.backup

`who` - See Users Logged On

who prints a list of all users currently logged on to the machine

$ who
tsoro  pts/0        2012-08-12 13:41 (dsl092-066-161.bos1.dsl.speakeasy.net)
rouilj   pts/1        2012-08-12 04:25 (pool-74-104-161-40.bstnma.fios.verizon.net)
eb       pts/2        2012-08-12 08:19 (pool-96-237-251-11.bstnma.fios.verizon.net)

who also provides information about each user's login session
It shows the time they logged in
It also shows the machine from which the user connected

who am i will show the user who is logged into a specific terminal

$ who am i
tsoro  pts/0        2012-08-12 13:41 (dsl092-066-161.bos1.dsl.speakeasy.net)

This can be useful if you find an unattended terminal
You can run the same command without the spaces ...
but it gives less information
```
$ whoami
tsoro
```

`finger` - Get information on Users

finger provides information about Unix accounts

$ finger tsoro
Login: ghoffman       			Name: Glenn Hoffman
Directory: /home/tsoro           	Shell: /bin/bash
On since Thu Sep 24 11:43 (EDT) on pts/5 from 158.121.249.7
   5 seconds idle
Mail forwarded to tsoros@gmail.com
New mail received Fri Sep 18 14:00 2015 (EDT)
     Unread since Fri Sep 18 07:43 2015 (EDT)
Plan:
Office:        Science 3-92A (Pterosaur poster on door)           
Office Hours:  Tuesday & Thursday, 12:30 - 1:30 PM and 5:30 - 6:30 PM 
On Campus:     Wednesday 1 - 6PM Appointment needed on Wednesday
Classes:       IT 244-01   Introduction to Linux/Unix             TuTh 2:00 - 3:15 PM  Science S3-143 (IT Lab)
               IT 244-02   Introduction to Linux/Unix             TuTh 4:00 - 5:15 PM  Science S3-028 (Web Lab)  
               IT 341_02   Introduction to System Administration  TuTh 7:00 - 8:15 PM  Science S3-143 (IT Lab)
Home Address:  40 Central Street     617-821-3936 (home; 9am - 9pm only)
               Somerville, MA 02143

finger, like mv, has two functions
When used without an argument ...

finger shows every user currently logged in

$ finger
Login     Name            Tty      Idle  Login Time   Office     Office Phone
eb        Ethan Bolker    pts/4    3:35  Sep 22 19:19 (pool-108-26-203-122.bstnma.fios.verizon.net)
ghoffman  Glenn Hoffman   pts/5          Sep 24 11:43 (158.121.249.7)
root      root           *tty1      52d  Mar 11  2015

You can also use a last name with finger

$ finger hoffman
Login: ghoffman       			Name: Glenn Hoffman
Directory: /home/ghoffman           	Shell: /bin/bash
On since Thu Sep 24 11:43 (EDT) on pts/5 from 158.121.249.7
   2 seconds idle
Mail forwarded to glennhoffman@mac.com
New mail received Fri Sep 18 14:00 2015 (EDT)
     Unread since Fri Sep 18 07:43 2015 (EDT)
Plan:
Office:        Science 3-92A (Pterosaur poster on door)           
Office Hours:  Tuesday & Thursday, 12:30 - 1:30 PM and 5:30 - 6:30 PM 
On Campus:     Wednesday 1 - 6PM Appointment needed on Wednesday
Classes:       IT 244-01   Introduction to Linux/Unix             TuTh 2:00 - 3:15 PM  Science S3-143 (IT Lab)
               IT 244-02   Introduction to Linux/Unix             TuTh 4:00 - 5:15 PM  Science S3-028 (Web Lab)  
               IT 341_02   Introduction to System Administration  TuTh 7:00 - 8:15 PM  Science S3-143 (IT Lab)
Home Address:  40 Central Street     617-821-3936 (home; 9am - 9pm only)
               Somerville, MA 02143
               

Login: ghoffmn        			Name: Glenn Legacy Hoffman
Directory: /home/ghoffmn            	Shell: /bin/bash
Last login Mon Jul 13 13:14 (EDT) on pts/5 from dsl092-066-161.bos1.dsl.speakeasy.net
Mail forwarded to glennhoffman@mac.com
Mail last read Thu May 28 18:30 2015 (EDT)
Plan:
Office:         McCormack M-3-607                 Fall 2014
Office Hours:   Tuesday & Thursday, 10:00 - 12:00 PM and by appointment
Classes:        
	IT 341-2  Introduction to System Administration  TuTh  12:30-1:45  S3-148  (IT Lab)
	IT 244-1  Introduction to Linux/Unix             TuTh   2:00-3:15  S3-028  (Web Lab)
	IT 244-3  Introduction to Linux/Unix             TuTh   4:00-5:15  S3-148  (IT Lab)
	IT 244-2  Introduction to Linux/Unix             TuTh   5:30-6:45  S3-028  (Web Lab)
Home Address:   40 Central Street     617-821-3936 (home; 9am - 9pm only)
                Somerville, MA 02143


Login: it244gh        			Name: Glenn Hoffman Dummy
Directory: /home/it244gh            	Shell: /users/nologin
Never logged in.
Mail forwarded to glennhoffman@mac.com
No mail.
Plan:
This account is a test account for Glenn Hoffman teaching it244