TCL and Expect

8/16/2019 TCL and Expect

1/19

Introduction to TCLTCL Fundamentals

TCL odditiesMore TCL syntax

Introduction to ExpectExpect fundamentals

Expect examplesThe end

TCL and Expect

William Tracy

Thursday, February 19, 2009

William Tracy TCL and Expect


2/19





What is TCL?

Unix scripting language

Intended for embedding in applications

Shell-like syntax

Low memory footprint



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Input, Output, and Variables

Listing 1: File 0-io

1 #! / u s r / b i n / t c l s h23 s e t l a n g u a g e TCL4 puts ” H e l l o , $ l an g ua g e ! ”5 puts { H e l l o , $ la n g ua ge ! }

67 puts s td o u t ” E n t e r a s t r i n g : ”8 g e t s s t d i n i n p u t9 puts s t d o ut ”You s a i d $ i n p u t ! ”



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Control flow

Listing 2: File 1-if

1 #! / u s r / b i n / t c l s h23 s e t f l a g t r u e4 i f { $ f l a g } {

5 puts Tru e !6 } e l s e {7 puts F a l s e !8 }


I d i TCL


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Loops

Listing 3: File 2-loops

1 #! / u s r / b i n / t c l s h

23 s e t i n p u t n4 w h i l e { $ i np u t != y } {5 puts ” Would you l i k e t o q u i t ? ”

6 g e t s s t d i n i n p u t7 }89 f o r { s e t i 0} { $ i < 10} { i n c r i } {

10 puts $ i

11 }William Tracy TCL and Expect

I t d ti t TCL


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Example

Listing 4: File install1 #!/ us r / bi n / t c l s h2

3 s e t f a i l t r u e45 p u t s ” I n s t a l l o p t i o n a l c o mp o ne n ts ? ”6 g e t s s t d i n d at a7 i f { $ d at a != y} {8 e x i t9 }

1011 i f { $ f a i l } {

12 p u t s ” H ar dw ar e n o t s u p p o r t e d . I n s t a l l w i l l c a u s e s p o n t a n e o u s ”13 p u t s ” c o m b u s t i on . C o nt i nu e ? ”14 g e t s s t d i n d at a15 i f { $ d at a != y} {16 e x i t17 }18 }1920 p u t s ” I n s t a l l w i l l t a k e 1 0 G b. C o n t i n u e ? ”

21 g e t s s t d i n d at a


Introduction to TCL


7/19





Whitespace

Listing 5: File 3-ifbroken1 #! / u s r / b i n / t c l s h23 s e t f l a g t r u e4 i f { $ f l a g }

5 {6 puts Yay!7 }


Introduction to TCL


8/19





Whitespace

Listing 6: File 4-iffixed

1 #! / u s r / b i n / t c l s h23 s e t f l a g t r u e4 i f { $ f l a g } {5 puts Yay!

6 }7 i f { $ f l a g } \8 {9 puts Yay!

10 }


Introduction to TCL


9/19





Whitespace

Listing 7: File 5-comments

1 #! / u s r / b i n / t c l s h23 puts ” B l a b l a ” # Witt y comment

45 puts ” B l a b l a ” ; # Witt y comment


Introduction to TCL


10/19





Grouping

Quotes group arguments Braces disable substitution in a group

Square brackets are replaced by the execution of thatcommand

Listing 8: File 6-bracketsputs [ expr 2 + 2 ]


Introduction to TCL


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Data Structures

Listing 9: File 7-structures

1 #! / u s r / b i n / t c l s h

23 s e t m y l i s t {a b c d}4 puts $ m y l i s t5 puts [ l i n d e x $ m y l i s t 0 ]6 puts [ l l e n g t h $ m y l i s t ]78 s e t m y a rra y ( f o o ) b a r9 s e t myarr ay ( bazz ) buzz

10 p a r r a y m ya rr ay

11 puts $m ya rr ay ( fo o )William Tracy TCL and Expect

Introduction to TCL


12/19

TCL FundamentalsTCL oddities

More TCL syntaxIntroduction to Expect

Expect fundamentalsExpect examples

The end

Procedures

Listing 10: File 8-proc

1 #! / u s r / b i n / t c l s h23 proc sum { a rg 1 a rg 2 } {4 s e t x [ expr { $ a r g 1 + $ a r g 2 } ]

5 r e t u r n $x6 }7 puts ”The sum o f 2 + 3 i s : [ sum 2 3 ] ”


Introduction to TCL


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The end

What is Expect?

Extension to TCL

Spawns and manages child processes

Handles stdin and stdout of children


Introduction to TCL


14/19




The end

Spawn

Listing 11: File 9-spawn

1 #! / u s r / b i n / e x p e c t 2 spawn c at 9−spawn

3 puts $ s p a w n i d


Introduction to TCLTCL F d l


15/19




The end

Expect

Listing 12: File 10-expect

1 #! / u s r / b i n / e x p e c t 2 spawn c a t 10 −expect3 e x p e c t e xp e c t

4 puts $ e x p e c t o u t ( b u f f e r )5 e xp ec t $ s p a w n i d e o f


Introduction to TCLTCL F d t l


16/19




The end

Send

Listing 13: File 11-send1 #! / u s r / b i n / e x p e c t 23 spawn b an ne r4 e x p e c t M e ss a ge :5 s e n d :− ) \ n6 e x p e c t e o f




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The end

Autoinstall

Listing 14: autoinstall1 #!/ usr / bi n / ex pe ct 23 s p aw n . / i n s t a l l45 e x p e c t ” I n s t a l l o p t i o n a l c om po ne nt s ? ”6 s e n d y\n78 e x pe c t ” c o mb us ti on . C on ti nu e ? ” {9 s e n d ”n\n”

10 } ” I n s t a l l w i l l t a k e 1 0 G b. C o n t i n u e ? ” {11 s e n d y\n12 }1314 e xp e c t e o f




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The end

Hunt the Wumpus




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The end

The book


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TCL and Expect