Introduction to Unix Commands and Shell Scripting with Dr. Shu-Ching Chen

Tutorial ofUnix Command & shell scriptS 5027 Professor: Dr. Shu-Ching Chen TA: Hsin-Yu Ha

Outline • Log in • Unix Basic Commands • Shell script

How to log in • Download putty from http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

Connect to the server • The host is margay.cs.fiu.edu 1 2 3 4

Log in / Account information • Account information • Login as : Your FIU username • Password : Your first initial + PantherID + Your last initial For exmaple, Steven Jackson with PID 1234567 should have password s1234567j

Commands about Files (1) • ls : list the contents of your current directory. • Format • Options • -a : list all the files include the hidden ones • -l : list not only the files name but also the related info • -t : list the contents by modified date ls [option] [directory][file]

Commands about Files (2) • File permission • Field1 : A set of ten permission flags • Field2 : link count • Field3 : owner of the file • Field4 : associated group of the file • Field5 : size • Field 6-8 : Last modification date • Field9 : file name

Commands about Files (3) • chmod : change the permission flags of the files • Format • Example • chmodg+wmyfile • chmod g-rwmyfile • chmod u=rw go= myfile • chmod –R g+rwmyfile chmod [option] [types][+/-][types of permission] filename

Commands about Files (4) • pwd : print out the current working directory • cd : change directory • cd . (.) means the current directory • C (..) means the parent of current directory • Cd cd with no argument will return you to your home directory cd . cd .. cd

Commands about Files (5) • cp : copy files • Format • Options • -i : It can be used to avoid overwriting the original file • -r : Copy the folder and all the files and subfolders under it. • mv : move a file from one place to another or rename a file. • Format cp [option] File1 File2 mv File1 File2

Commands about Files (6) • mkdir : making directory • Format • rm : remove files or directories • Format • Option • -i : ask before actually delete • -r : delete the folders and all the files and subfolders under it mkdirDirectory_name rm [option] file1 file2 file3…

Commands about Files (7) • test : A command in Unix that evaluates conditional expressions. • Format or • The functions will return true if the object exist or the condition specified is true. • File functions • -d Filename : Filename is a directory • -s Filename : Filename has a size greater than 0 • -f Filename : Filename is a regular file test expression [ expression ]

Commands about File’s contents (1) • cat : display the contents of a file on the screen • Format • head : display the first ten lines of a file to the screen • Format • tail : display the last ten lines of a file to the screen • Format cat file1 head –n file1 tail –n file1

Commands about File’s contents (2) • wc : word count • Format • Options • -w : find out how many words the file has • -l : find out how many lines the file has wc [options] file

Commands about File’s contents (3) • grep : It searches files for the specified words or patterns. • Format: • Options: • -c : Display the number of columns which satisfied the pattern. • -i : Ignore case distinctions in both the PATTERN and the input files. • -v : Invert the sense of matching, to select non-matching lines. grep [options] [pattern] file

Pipe : It cause the execution of multiple processes from one single line A | B | C

Commands about File’s contents (4) • Redirection • > and >> can be used on the output of most commands to direct their output to a file. • Examples

Commands about Text processing (1) • sort : sort lines of a text file or files • Default : sort without any option will sort the file alphabetically • Format • uniq : remove duplicate adjacent lines from sorted file. sort [option] file

Commands about Text processing (2) • sed: One ultimate stream editor • Detail Tutorial : http://www.grymoire.com/Unix/Sed.html • Important function -> Substitution • Format : sed 's/term1/term2/g‘ filename

Commands about Text processing (3) • cut : extract sections from each line of a file. • Format • Option • -c : character • -f : field • -d “:” : delimiter (default is a tab) • Range • N-M • N- • -M cut [options] [range] filename

Shell script intro (1) • Scripts are collections of commands that are stored in a file. • Detail Tutorial http://www.freeos.com/guides/lsst/ • Basic Vi commands • vim filename • i : switch to the editing(insert) mode • Esc +:q! Leave the vim program without saving the file • Esc +:w Save the file • Esc +:wq Save the file and leave the vim program

Shell script intro (2) • First shell script • Note that to make a file executable, you must set the eXecutable bit, and for a shell script, the Readable bit must also be set.

Shell script intro (3) • Variable

Shell script intro (4) • IF LOOP

Shell script intro (5) • For Loop

Shell Script Intro (6) • Useful concept $( commands)

Introduction to Unix Commands and Shell Scripting with Dr. Shu-Ching Chen