Basic unix shell scripting tutorial revision

I wanted to revise shell scripting to my friend. Here are the list of commands that we used.

The kernel: agent
The shell: interface between the user and the kernel,
command line interpreter
bash
tcsh
etc
http://unixhelp.ed.ac.uk/shell/oview2.html

(show terminal)
You can scroll up and down with arrow key...





Everything in unix is either file or a process. Thats why no exe/virus.

The directory structure is simple idea. The structure is like an inverted tree.
(how to drag the file into terminal)

http://linux.about.com/od/commands/l/blcmds.htm


ls

ls -a

ls *.mat
ls a?.mat

mkdir testdir

cd testdir
mkdir direc1

cd .. (paraent directory)
cd . (current dir)

pwd (print working directory)

ls testdir (list the contents of testdir)

can use full filename

ls testdir/direc1


cd (go home!)


cp fullpathname of a file

mv fullpathname of a file

rm

clear

whoami

which


%====================== Break Break!
create a test.txt file

cat test.txt (can be used to display the contents)

grep : searches files for specified words or patterns

grep Science science.txt

The grep command is case sensitive; it distinguishes between Science and science.

To ignore upper/lower case distinctions, use the -i option, i.e. type

% grep -i science science.txt

To search for a phrase or pattern, you must enclose it in single quotes (the apostrophe symbol). For example to search for spinning top, type

% grep -i 'spinning top' science.txt

How to check mail from terminal

cat text1.txt text2.txt>text3.txt
Concatenate 1 and 2 into 3

append using >>


mail -s "sending history" dfe @gemail.com < history
s: subject

samething with a pipe

date | mail -s "let's try a pipe" blsdfi@asdfe.com

The result of this operation is that the output of the who command will be sent directly to the input of the mail command, without the intermediate step of storing the data in a file.




man command#name (manual of the command)

kill #processID (mac, I learned)

opendiff file file2


===============
Unzip:

gunzip test.txt.gz


chmod u+rwx filename

To give yourself permission to execute a file that you own:

   chmod u+x file1
   x: execute
   r: read
   w: write

Setting access permissions numerically

There is a shorthand way of setting permissions by using octal numbers. Read permission is given the value 4, write permission the value 2 and execute permission 1.

    r  w  x
    4  2  1
These values are added together for any one user category:

    1   =   execute only
    2   =   write only
    3   =   write and execute (1+2)
    4   =   read only
    5   =   read and execute (4+1)
    6   =   read and write (4+2)
    7   =   read and write and execute (4+2+1)
So access permissions can be expressed as three digits. For example:

                          user    group   others

    chmod 640 file1       rw-     r--     ---
    chmod 754 file1       rwx     r-x     r--
    chmod 664 file1       rw-     rw-     r--
 
 
 

history


http://usefulcodes.blogspot.com/search/label/mac
http://usefulcodes.blogspot.com/2011/11/using-imagemagick-shell-command-to-crop.html
http://usefulcodes.blogspot.com/search/label/unix



for statement
http://unixhelp.ed.ac.uk/scrpt/scrpt2.6.2.1.html
http://unixhelp.ed.ac.uk/scrpt/scrpt2.6.3.2.html


making shell script:

save as display.sh
   cat display
   # This script displays the date, time, username and
   # current directory.
   echo "Date and time is:"
   date
   echo
   echo "Your username is: `whoami` \n"
   echo "Your current directory is: \c"
   pwd


========

ftp into another computer

 ftp> get image1.jpg
ftp> put asdf.png
 ftp> prompt
 mput [file]
Uploads multiple files matching [filespec]

bye


 vi ~/.bash_profile


 ==