Hands on Scripting

8/12/2019 Hands on Scripting

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217324234.xlsx.ms_office

S.NO CATEGORY COMMANDS SHELL

1 BASICS OPENING SCRIPT bash

EXTENSION .sh

RUN ./filename or sh filename.sh

INCLUDE #!/bin/bash

2 OPERATIONS ASSIGNMENT var=10, a=$var

USER INPUT read a

INCLUDE SPECIAL MEANING expr 2 \* 3

PRINT STRING $myvar

PRINT STRING WITH VALUE myvar value: $myvar

space needed between operators

and not in assignment

Date = `date`

ARITHMETIC result=`expr $num1 \* $num2`

PRINT echo $resultVALID OPERATORS +,-,*,/,%,=,

VARIABLES SCALARS

ARRAYS

ASSOCIATIVE ARRAYS

3 SYMBOLS COMMENT #

STATEMENTS SEPERATOR ;

ESCAPE SEQUENCE \

VARIABLE $STRING "" OR ''

COMMAND EXECUTION ` OR $()

BLOCK OF CODE {}

NO OPERATION :

TEST CONDITION []

STANDARD OPERATORS STDIN(0)

STDOUT(1)

HA

INT

INP


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STDERR(2)

REDIRECTION INPUT

APPEND MODE >>

3 DEBUG EXECUTED COMMANDS sh -x filename.sh

LINES READ sh -v filename.sh

4 LOOP FOR

for loop-variable in members

do

command

command

done

can also be used for the block

instead of do done

FOREACH NA

WHILE

while [ condition ]

do

command

command

done

There MUST be a space after [ and

before ]


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UNTIL

until [ condition ]

do

command

command

done

5 CONDITION EQUAL TO $a -eq 0 , $STRING = $STRING2

NOT EQUAL TO $a -ne 1 , $STRING != $STRING2

LESS THAN $a -lt 2

GREATER THAN $a -gt 3

LESS THAN OR EQUAL TO $a -le 4

GREATER THAN OR EQUAL TO $a -ge 5

6 BRANCHING IF ELSE

if condition1

then commands1

else commands3

fi

IF ELSE IF ELSE

if condition1

then commands1

elif condition2 then commands2

else commands3

fi

SWITCH CASE

case $cal in

add)

;;

sub)

;;

mul)

;;

div)

;;

esac

C


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UNLESS NA

7 COMMAND LINE SCRIPT NAME $0 (./FILENAME.sh)

ADDITIONAL ARGUMENTS $1

ARGUMENT COUNT $#

ENUMERATES $@ OR $*

EXIT VALUE OF LAST COMMAND $?

LINE NUMBER

REMOVES NEW LINE

REMOVES LAST CHARACTERanonymous VARIABLE

8 FUNCTIONS DEFINITION

function func_name

{

Body of function

}

Note:- all the arguments passed to

the function will be stored to $1, $2

variables

IMPORT source ./scripname

9 SUB SHELL RUNNING IN PARENT . ./FILENAME.sh

CHILD Default one

CO
mailto:$@%20OR%20$*mailto:$@%20OR%20$*


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10 CONFIGURATION

.bash_profile

.bashrc

.bash_logout

11 SIGNALS TRAP A SIGNAL $ trap command signal

IGNORE A SIGNAL $ trap signalRESET A SIGNAL $ trap signal

12 LISTS CREATE LIST NA

OPERATIONS INDEXSORT

CONCATENATE

APPEND

LENGTH

INSERT

RANGE

DELETE

REVERSE

DELETE AT LAST

13 NAMESPACE

13 STRING EQUAL

LAST

It encapsulates the commands and variables to ensure that they won't

interfere with the commands and variables of other namespaces


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LENGTH

RANGE

REPLACE

INDEX

MATCH

ADDITIONAL OPERATIONS

TO BINARY STRING

TO TCL STRING

SCAN

parses string using conversion

specifiers

14 SCOPE NA

15 INTERNALS NA

16 FILE ALL COMMANDS

OPEN

SEEK

MODE

diamond operator

17 ARRAYS INSERT AT LAST

ARRAY LENGTH

INSERT AT FIRST

REMOVES AT LAST

REMOVES AT FIRST

REVERSE

SORT

NA

NA


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JOIN

SPLIT

ASSOCIATIVE ARRAY DECLARE

DEFINE

ITERATE

KEYS

VALUES

18 HELP INFO man command

SOURCE NA

SOCKET

ERROR INFO

WINDOW SHELL

NA


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19 PATTERN MATCHING SYNTAX

OPTIONS !~

/g

/i

/x

s / pattern / replace /

tr / characters / repl-characters /

split ( /Pattern/, String )REFE


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TCL PERL

tclsh perl -e commands

.tcl .pl

tcl filename.tcl perl filename.pl

#!/usr/bin/perl

ALL LINES END WITH ;

set a 22,set b $a

$name = Aricent Tech;

( $a, $b) = ($c, $d); # Same as $a=$c; $b=$d;

gets stdin var $inputline = ;

expr 2 \* 3 also expr 2*3 works fine

set b {[expr $a+10]}

"a is $a" print Length of name : , length($name), \n;

spaces not needed between operators

print "@array"; #print whole array with spaces

print @array; #print whole array without spaces

set Date [date] system(date);$Date = date`;

set b [expr $a+10] $S = $A + $B

puts "x is $x" print "@array"; print $s;

$scalars

@arrays

set student(name) John %associative_arrays

# # , =begin =cut

stdin STDIN(0)

stdout STDOUT(1)

NDS ON SCRIPTING

ODUCTION TO VARIOUS SHELLS

T ASSIGNMENTS AMD OUTPUT

SYMBOLS AND OPTIONS


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stderr STDERR(2)

ERROR HANDLING

catch {expr {2 +}} msg

use warnings

use strict

error "bad argument"

The next command starts the next iteration of the

loop.

The last command immediately exits the loop inquestion.

The redo command is used to start processing of the

current iteration again.

for {set x 0} {$x= 0} {

puts "[incr lineCount]: $line"

}

while (CONDITION) {

# Code block executed if condition is true.

}

LOOPING CONSTRUCTS


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NA

until (CONDITION) {

# Code block executed while condition is false.

}

$a == 0 , $STRING == $STRING2 $STRING eq $STRING2, $a == 0

$a != 1 , $STRING != $STRING2 $STRING ne $STRING2, $a != 1

$a < 2 $STRING lt $STRING2, $a < 2

$a > 3 $STRING gt $STRING2, $a > 3

$a = 5

if {expr1} {

puts "vbl is one ; #body1

} else {

puts "vbl is not one or two"

}

if (CONDITION) {


} else {

# Code block executed if condition is false.

}

if {expr1} {


} elseif {$vbl == 2} {

puts "vbl is two } else {


}

if (expr1){


} elsif ($vbl == 2){ puts "vbl is two

} else {


}

set foo "abc"

switch abc

a - b {expr 1}

$foo {expr 2}

default {expr 3}

RANCHING STATEMENTS

ONDITIONAL OPERATORS


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NA

unless (CONDITION) {

# Code block executed if condition is false.

} elsif (CONDITION FALSE 1) {


} else (CONDITION FALSE 2) {


}

$argv0 $0 for script name. Arguments stored in @ARGV

$argv1 $ARGV[0]

$argc $#ARGV+1

$argv @ARGV

$.

chomp ($price);

chop($price);$_

proc decr {x {y 1}} {

expr $x-$y

}

sub (Arguments) {

}

Parameters passed to a subroutine can be accessed in

a subroutine using a special variable @_

proc sum args { set s 0

foreach i $args { incr s $i } return $s

}

sum 1 2 3 4 5

Package package_name;

BEGIN {

# initialization statement

}

Sub function_name {

#body of function

}

Return 1;

END {

#clean up statement

}

Save this file as package_name.pm

source ./scripname

use package_name;

package_name::function_name();

catch {exec grep foo


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fconfigure $f -translation binary

FOR BINARY ENCODED FILE HANDLER

set tList {{one} {two} {three}}

Or

set tList [list one two three]

Or

set tList *split one .two .three .+

lindex {a b {c d e} f} 2 --> c d e

lsort {red green blue} -->blue green red

concat a b {c d e} {f {g h}} -->a b c d e f { g h }

lappend var 2 --> 2 APPENDED IN END

llength {a b c d e} --> 5

linsert $tList 1 --> INSERT IN INDEX 1

lrange {a b c d e} 0 1 --> RETURNS a b

namespace eval Counter {

namespace export bump

variable num 0

proc bump {} {

variable num

incr num

}

}

One can then access proc bump using

Counter::bump from global namespace

set isitEqual [string equal $x1 $string] ; #

Returns 1 if equal else 0.

string last a 0a23456789abcdef 15

# will return 10. Here index within which the

occurrence has to be found is 15.

LIST DATA STRUCTURES

STRING OPERATIONS


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string length string;

string range string first last

string replace string first last ?newstring?

string index string charIndex

string match ?-nocase? pattern string

regexp format split binary regsub scan joinappend

formatString ?arg arg ...?

string formatString ?varName varName ...?

set string "08:08" ;# *Not* octal!

if {[scan $string "%d:%d" hours minutes] != 2} {

error "not a valid time string"

}

global uplevel upvar my local

info rename trace

open gets seek flush glob file close read tell cd

pid puts source eof pwd

set fl *open trn w+

open (FILE_HANDLE, EXPR ); EXPR = MODE + FILENAME

open (FILEHANDLE, "


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$URL = join (., @url);

@fields = split ( / : / , "1:2:3:4:5");

set student(name) John

% geography = (Bangalore , India , London,

England);

% geography = (Bangalore" => India",

London" => England");

($city, $country) = each %geography;

@cities = keys %geography;

@countries = values %geography;

% info commands s* socket subst split source switch spinbox scale

set scan seek scrollbar selection string

perldoc -f perlfunction

man n command

Evaluate a file or resource as a Tcl script

source

socket option addr port

server option creates server socket

Global variable errorInfo provides stack trace

set errorInfo

Wish: Windowing Shell

button .hello -text "Hello, world" -command

exit

pack .hello

MAY I HELP YOU

REGULAR EXPRESSIONS


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regexp -all -- {\S+} $line pattern_to_match =~ /pattern/;

if (m/$pattern/) {

print "Found $pattern \n";

}

is just the negative of =~

global -This option finds all occurrences of the

pattern in the string. A list of matches is returned.

case-insensitive - This option ignores the case ofcharacters in the string.

Ignore whitespaces

Replaces the sub- string matched by pattern with

replace (once) and returns the number of

replacements (obviously 0 or1)

Translates characters (one by one), as specified by

characters with

repl-characters and returns the number of

replacements.tr is always global

my @fields = split ( /\s+/, $string);RENCING & DE REFERENCING


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PYTHON

python

.py

python filename.py, execfile('script.py')

#!/usr/bin/python

x = [0,1,2],

writer=raw_input('Please enter') or

year=int(year)

\*

os.system(command) or

from datetime import date

now = date.today()

s = s + i

print 'Hello world' OR print s

#, Triple quotes - multi line string

sys.stdin

sys.stdout


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sys.stderr

try: n = float(s)

numbers.append(s)

except ValueError, msg:

not_numbers.append(str(msg))

for i in range(1,7):

while condition:

action


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s == 'string', a == 0

a != 1 , STRING != 'STRING2'

a < 2

a > 3

a = 5

if condition:

action

if condition1:

action1elif condition2:

action2

else:

action3


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sys.argv[0]

sys.argv

def func(args):

Actually returns a value anyway: 'None'

import module

module.submodule.x

OR

from module import submodule

submodule.x

map(func,list), reduce(func,list),

filter(func,list)


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shoplist = ['apple', 'mango', 'carrot',

'banana']

olditem = shoplist[0]shoplist.sort()

shoplist.append('rice')

len(shoplist)

shoplist[1:3]

del shoplist[0]

shoplist.reverse()

shoplist.pop()

re MODULE has re.compile, obj.match,

re.search, obj.group,re.split,re.findall,

re.finditer, re.sub,


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hollow=hollow.replace('Shadow','Light')

index=song.find('a')

Built-in (Python),Global (module),Local

(function)

F=open(filename,w)

f.write(poem)

f.close()

line = f.readline()

TUPLE

zoo = ('wolf', 'elephant', 'penguin') new_zoo

= ('monkey', 'dolphin', zoo)

len(new_zoo)

new_zoo[2][2] --> penguin


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DICTIONARY

ab = { 'Swaroop' :

'[email protected]',

'Larry' : '[email protected]',

'Matsumoto' : '[email protected]','Spammer' : '[email protected]'

}

ab['Guido'] = '[email protected]'

del ab['Spammer']

ab.items():

ab.has_key('Guido')

help()


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import re

seq =

"MAKEVFSKRTCACVFHKVHAQPNVGITR"

zinc_finger = re.compile('C.C..H..H') #compile regular expression pattern

print zinc_finger.findall(seq)

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