LEARN SHELL

1.ORACLE_SID=lsh

 

2.export ORACLE_SID

 

3.#!/bin/bash

 

4.Shell variables are un-typed and may contain integer or text,Number with a decimal point will be treated as text(3.14)

 

5.variable scope: local script or all session. when export variable, variable are used in subsequently.

 

6.$ORACLE_SID     use variable

   ${ORACLE_SID}_SID

 

7.echo  $ORACLE_SID

 

8.# this  is comment

 

9.  scriptname.sh

 

10.chmod ugo+x  scriptname.sh

 

11. ./name.sh

 

12.[ $ORACLE_SID="lsh" ]  conditional testing ,

 

13.if

      then

     fi

   

     if

       then

     elif

       then

     else

     fi

 

14. matmathics comparators

      -lt    <

      -le   <=

      -gt   >

      -ge  >=

      -eq  =

      -ne  !=

 

15.string  comparators

     =

     !=

     string

 

16.file comparators

     -nt

     -ot

     -e

     -d

     -h

     -s

     -r

     -w

     -x

     -f

 

17.complex comparator

 

    -a

    -o

     !

 

18.if [ $ORACLE_SID="lsh" ]

 

19.if [ $ORACLE_SID -lt 30 ]

 

20.if [ -e /u01/oracle/bin.sqlplus ]

 

21.if [ -e /u01/oracle/dbs/spfile${ORACLE_SID}.ora -a -e $ORACLE_SID/dbs/init$ORACLE_SID.ora ]

 

22.if [ $ORACLE_SID ]   check variable

 

22.ps -ef | grep "$ORACLE_SID"

 

23. case    in        matching string

      a)

      echo "" ;;

      b)

      echo "" ;;

      c)

      echo "";;

      *)

      echo "";;

      esac

 

24. while [ $ORACLE_SID="lsh" ]; do

 

          echo ""

          i=`expr $i + 1`

     done

 

25.for var in 1 a  3;do

         echo ""

    done

     

26.break; continue;

 

27.[ -r /u01/oracle ] && echo "this is"

     [ -r /u01/orace  ] || { echo "can not read"; exit 1; }  

  

28.{ echo "can not write" ; exit 1 ; }   anymous function

 

29.$1,$2,$3

     var=$1       specify the value of var is from running parameter    

     $* //specify all the parameters

     for var in $*;do               ./test 1 2 3

     echo "===$var==="

     done

     $#//specify the numbersof all the parameters

30.    

    #!/bin/sh

   echo “What is your favourite OS?”
   select var in “Linux” “Gnu Hurd” “Free BSD” “Other”; do
   break;
   done
   echo “You have selected $var”

 

   What is your favourite OS?
  1) Linux
  2) Gnu Hurd
  3) Free BSD
  4) Other
  #? 1
  You have selected Linux

 

 31."$SHELL"

      '*.jpg'   

      "/$SHELL"

 

34.

#!/bin/bash       
help()                   //must first declare, then use fun.
{
cat << HELP
"this is lp"
HELP
exit 0
}
[ -n "$SHELL" ]&&help   

 

35.

  "$SHELL"

  '$SHELL'

  "*.jpg"

 

      

Prevent the wildcard(*) and variable expansion

32.cat <<help

     sdsdsd

     sds

     help

    Here Document:When you want to pass a few lines of text to a command,we use <<help ------------help

33.exit 0   exit function

34.sh -x test.sh

     sh -n test.sh

35.shift remove the first parameter from parameter list

     shift 1

     shift 2

36.ctrl+a               !!

     ctrl+e               !$

     ctrl+l

     ctrl+u

     ctrl+k

     ctrl+y

     ctrl+r

     ctrl+c

     ctrl+d

     ctrl+z

     ./runinstall&

    

37. ls;pwd;date     Multiple commands separated by semicolons in the  line.

      (ls;date;pwd)>cat.bbk

 

38.type pwd 

39.alias  vi=vim

     alias  ll='ls-l'

     unalias    vi

40.cd /var/log

     cat /dev/null >message

     cat /dev/null >wtmp

41.echo "this is `pwd` directory"    `pwd`  Command substitution

42.echo ${name}  display variable

     unset  name      clear  variable

     set     display all variable

    

 43.name=bbk

      readonly bbk

 44.PATH=${PATH}:/bin/bash

      ${#PATH}  the length of the PATH

 45.arry=(abc bb cc dd)

      echo ${#arry}

      echo ${#arry[*]}

      echo ${#arry[1]}

      echo ${#arry[2]}

      echo ${arry[0]}

46.#!bin/bash

        dno=$1

        sqlplus hr/hr <<EOF >select.sql

        select * from emp where deptno=$dno;

        EOF

    

47.name=lsh

     echo 'this is $name'   

     this is $name

47.>        redirect standoutput

     >>  

     2>      redirect errorout

     2>>

48.ps -ef | grep oracle

49.echo "This is \\\\"

     This is "\"

48.