Introduction to UNIX and shell cripting

• Introduction to Unix and its architecture• Learn to use basic Unix commands • Learn to use vi editor • Learn to write shell scripts • Learn to register and run shell scripts from oracl

• Introduction to Unix and its architecture

• Learn to use basic Unix commands

• Learn to use vi editor

• Learn to write shell scripts

• Learn to register and run shell scripts from oracle applications

Kernel – is the single large program which resides in

the memory which is the operating system It

manages File system, Memory, I/O and Processes.Shell – is a command interpreter which provides the user interface for the UNIX operating system

 HP-UX - HP UNIX developed by HP

 SunOS and Solaris – Developed by Sun

Microsystems

 AIX – Developed by IBM

 SCO Unix – Developed by SCO

 Linux - Free Source code

 BSD – Berkley Software Design

Bourne C TC Korn BASH

* not the default setting for this shell

There are three types of file access supported by

UNIX

 r – read, view the contents of a file or a directory

 w – write, edit file/directory contents

 x – execute, run executable file

- rwx r-x r 1 user1 oracle 858 Feb 22 22:28 file1.txt

group

size

Modification date/time

File name User

permissions

Group permissions

Other Permissions

links

For example:

Suppose you type in ls -l and the result is

ls - List directory contents

cd - Change the current directory

cp - Copy files and directories

mv - Move (rename) files

mkdir - Make a directory

rm - Remove files or directories (Use with Caution)

rmdir – Delete a directory (Use with Caution)

echo – Display a line of text

cat – Concatenate files and print on the std output

date – Print the system date and time

head – Output the first part of files

tail – Output the last part of files

pwd – Print name of current/Working Directory

man – Format and display the on-line manual pages

who – Show who is logged on

chmod - Change file access permissions

grep – Print lines matching a pattern

find – Search for files in a directory hierarchy

diff – Find differences between two files

ps - Report process status

cut – Remove sections from each line of files

su – run a shell with substitute user and group IDs

wc - Print the number of bytes, words, and lines in files

ln - Make links between files

alias/unalias - Shorthand for a command or commands sort - Sort lines of text files

exit – Exit the current shell with status

shift – Shift positional parameters

env – Display the environment variables

logout - Exit a login shell

There are 2 types of variables in Unix.

 Environment variables

 Shell variables

As per conventions environment variables will be in

uppercase and Shell variables will be in lowercase.

Example :

APPL_TOP=/srv/115102/inst/visappl

pathseg=/home/oracle/bin

today=`date`

Redirection operators:

Output redirection : >, |, >>

Input redirection : <

Example:

cat test1 test2 > test3

cat test2 >> test1

ls –l | grep new

sort < test.txt > sortedtest.txt

vi – Visual text editor

vi <file_name> - to open the any text file in vi editor

Two modes of vi

 Insert mode – a or i

a - enter append mode

i - enter insert mode

h - move cursor left

j - move cursor down

k - move cursor up

l - move cursor right

x - delete char under cursor

r - replace one character under the cursor

u - undo the last change to the file

^ - Goto the beginning of the line

$ - Goto the end of the line

[n]dd - delete line/lines from the cursor position

[n]yy - yank (copy) line/lines from the cursor position

p - paste the yanked line/lines below the cursor position

ctrl-f - Scroll forwards one page

ctrl-b - Scroll backwards one page

:w - Save the file

Conventionally, a shell script should start with a line:

#!/bin/ksh

Example shell script

#!/bin/bash

echo “Hello $USER”

echo “Today is “ `date`

echo “You are in directory $PWD”

exit 0

Ex: ls –lrt, myshell.sh oracle

$1 to $9 – will give the arguments 1 to 9 To get

remaining we need to use shift command.

$@ - will give the complete list of all the arguments to that shell

$? - returns 0 if the last command is executed

successfully,

else non zero

$# - returns the number of arguments

$! - returns the last command PID run in bg (using &)

$$ - returns the current shell PID

sqlplus -s <userid>/<passwd>@<dbsid> @<filepath>/<filename>

Example 1:

sqlplus -s $UID/$PWD@$CONSTR@$EXECDIR/sql/oa_com_monitor_cmrun

Example 2 :

st_date=`sqlplus -s $UID/$PWD@$CONSTR << EOF

set head off

set feedback off

select to_char(sysdate-15,'DD-MON-YYYY') from dual;

EOF`

The shell script can have either of the 2 extensions.

.prog or sh

.prog :

1 Create a soft link to the shell without extension to

$FND_TOP/bin/fndcpesr

Ex: ln -s $FND_TOP/bin/fndcpesr $FND_TOP/bin/TEST

2 Grant execute permission to the both the files (.prog and the file without

extension)

Ex: chmod +x TEST.prog TEST

.sh :

Differences b/w prog and sh

.prog: will get the following parameters as default to the shell.

$1 - Connection string (userid/passwd@dbsid)

$2 - Fnd user id

$3 - Fnd user

$4 - Request id

.sh : will only get one parameter which as all the above along with

some additional ones

Ex: FCP_REQID=250898 FCP_LOGIN="APPS/APPS" FCP_USERID=1117

FCP_USERNAME="SRVCMGR" FCP_PRINTER="noprint"

FCP_SAVE_OUT=Y FCP_NUM_COPIES=0

QUESTIONS ??