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Exploring Expect A Tcl-based Toolkit for Automating Interactive Programs By Don Libes
December 1994
Pages: 602

| Table of Contents | Sample Chapter | Colophon

Chapter 1 Intro—What Is Expect?
1. Ouch, Those Programs Are Painful!
2. A Very Brief Overview
3. A First Script—dialback
4. Total Automation
5. Differing Behavior When Running Non-Interactively
6. Partial Automation
7. Dangerous, Unfriendly, Or Otherwise Unlikable User Interfaces
8. Graphical Applications
9. A Little More About Tcl
10. Job Control
11. Background Processes
12. Using Expect With Other Programs
13. Using Expect On UNIX
14. Using Expect On Other Operating Systems
15. Using Expect In Real Applications
16. Using Expect In Commercial Applications—Legalese
17. Obtaining Expect and the Examples
18. Expect And Tcl Resources
19. Exercises
Chapter 2 Tcl—Introduction And Overview
1. Everything Is A String
2. Quoting Conventions
3. Expressions
4. Braces—Deferring Evaluation
5. Control Structures
6. More On Expressions
7. Lists
8. More Ways To Manipulate Strings
9. Arrays
10. Indirect References
11. Handling Errors
12. Evaluating Lists As Commands
13. Passing By Reference
14. Working With Files
15. File I/O
16. Executing UNIX Commands
17. Environment Variables
18. Handling Unknown Commands
19. Libraries
20. Is There More To Tcl?
21. Exercises
Chapter 3 Getting Started With Expect
1. The send Command
2. The expect Command
3. Anchoring
4. What Happens When Input Does Not Match
5. Pattern-Action Pairs
6. Example—Timed Reads In The Shell
7. The spawn Command
8. The interact Command
9. Example—Anonymous ftp
10. Exercises
Chapter 4 Glob Patterns And Other Basics
1. The * Wildcard
2. More Glob Patterns
3. Backslashes
4. Handling Timeout
5. Handling End Of File (eof)
6. Hints On The spawn Command
7. Back To Eof
8. The close Command
9. Programs That Ignore Eof
10. The wait Command
11. Exercises
Chapter 5 Regular Expressions
1. Regular Expressions—A Quick Start
2. Identifying Regular Expressions And Glob Patterns
3. Using Parentheses To Override Precedence
4. Using Parentheses For Feedback
5. More On The timed–read Script
6. Pattern Matching Strategy
7. Nested Parentheses
8. Always Count Parentheses Even Inside Of Alternatives
9. Example—The Return Value From A Remote Shell
10. Matching Customized Prompts
11. Example—A Smart Remote Login Script
12. What Else Gets Stored In expect_out
13. More On Anchoring
14. Exercises
Chapter 6 Patterns, Actions, And Limits
1. Matching Anything But
2. Really Complex Patterns
3. Really Simple Patterns
4. Matching One Line And Only One Line
5. Tcl's string match Command
6. Tcl's regexp Command
7. Tcl's regsub Command
8. Ignoring Case
9. All Those Other String Functions Are Handy, Too
10. Actions That Affect Control Flow
11. Example—rogue
12. Character Graphics
13. More Actions That Affect Control Flow
14. Matching Multiple Times
15. Recognizing Prompts (Yet Again)
16. Speed Is On Your Side
17. Controlling The Limits Of Pattern Matching Input
18. The full_buffer Keyword
19. Double Buffering
20. Perpetual Buffering
21. The Politics Of Patterns
22. Expecting A Null Character
23. Parity
24. Length Limits
25. Comments In expect Commands
26. Restrictions On expect Arguments
27. eval—Good, Bad, And Ugly
28. Exercises
Chapter 7 Debugging Patterns And Controlling Output
1. Pattern Debugging
2. Enabling Internal Diagnostics
3. Logging Internal Diagnostics
4. Disabling Normal Program Output
5. The log_user Command
6. Example—su2
7. Recording All Expect Output
8. Sending Messages To The Log
9. About File Names
10. Log And Diagnostic State
11. Exercises
Chapter 8 Handling A Process And A User
1. The send_user Command
2. The send_error Command
3. The expect_user Command
4. Dealing With Programs That Reprompt
5. Dealing With Programs That Miss Input
6. Sleeping
7. Line Versus Character-Oriented And Other Terminal Modes
8. Echoing
9. Prompting For A Password On Behalf Of A Program
10. Security And Insecurity
11. Resetting The Terminal Upon Exit
12. More On The stty Command
13. The system Command
14. Redirecting The Standard Input Or Output
15. The expect_tty Command
16. The send_tty Command
17. Exercises
Chapter 9 The Expect Program
1. Expect—Just Another Program
2. Invoking Scripts Without Saying "expect"
3. Rewriting The #! Line
4. The .exp Extension
5. The—And Other Flags
6. The —c Flag
7. The -f Flag
8. Writing The #! Line
9. The −i Flag
10. The -n And -N Flags
11. The -d Flag
12. The -D Flag
13. The -b Flag
14. The - Flag
15. The interpreter Command
16. Exercises
Chapter 10 Handling Multiple Processes
1. The spawn_id Variable
2. Example—chess Versus chess
3. Example—Automating The write Command
4. How exp_continue Affects spawn_id
5. The Value Of spawn_id Affects Many Commands
6. Symbolic Spawn Ids
7. Job Control
8. Procedures Introduce New Scopes
9. How Expect Writes Variables In Different Scopes
10. Predefined Spawn Ids
11. Exercises
Chapter 11 Handling Multiple Processes Simultaneously
1. Implicit Versus Explicit Spawn Ids
2. Waiting From Multiple Processes Simultaneously
3. Example—Answerback
4. Which Pattern Goes With Which Spawn Id
5. Which Spawn Id Matched
6. Spawn Id Lists
7. Example—Connecting Together Two Users To An Application
8. Example—Timing All Commands
9. Matching Any Spawn Id Already Listed
10. The expect_before And expect_after Commands
11. Indirect Spawn Ids
12. Exercises
Chapter 12 Send
1. Implicit Versus Explicit Spawn Ids
2. Sending To Multiple Processes
3. Sending Without Echoing
4. Sending To Programs In Cooked Mode
5. Sending Slowly
6. Sending Humanly
7. Sending Nulls
8. Sending Breaks
9. Sending Strings That Look Like Flags
10. Sending Character Graphics
11. Comparing send To puts
12. Exercises
Chapter 13 Spawn
1. The Search Path
2. Philosophy--Processes Are Smart
3. Treating Files As Spawned Processes
4. Opening Ttys
5. Bugs And Workarounds
6. Process Pipelines And Ptys
7. Automating xterm
8. Checking For Errors From spawn
9. spawn -noecho
10. Example—unbuffer
11. Obtaining Console Output
12. Setting Pty Modes From spawn
13. Hung Ptys
14. Restrictions On Spawning Multiple Processes
15. Getting The Process Id From A Spawn Id
16. Using File I/O Commands On Spawned Processes
17. Exercises
Chapter 14 Signals
1. Signals
2. Signals In Spawned Processes
3. Notes On Specific Signals
4. When And Where Signals Are Evaluated
5. Overriding The Original Return Value
6. Using A Different Interpreter To Process Signals
7. Exit Handling
8. Exercises
Chapter 15 Interact
1. The interact Command
2. Simple Patterns
3. Exact Matching
4. Matching Patterns From The Spawned Process
5. Regular Expressions
6. What Happens To Things That Do Not Match
7. More Detail On Matching
8. Echoing
9. Avoiding Echoing
10. Giving Feedback Without -echo
11. Telling The User About New Features
12. Sending Characters While Pattern Matching
13. The continue And break Actions
14. The return Action
15. The Default Action
16. Detecting End-Of-File
17. Matching A Null Character
18. Timing Out
19. More On Terminal Modes (Or The -reset Flag)
20. Example—Preventing Bad Commands
21. Exercises
Chapter 16 Interacting With Multiple Processes
1. Connecting To A Process Other Than The Currently Spawned Process
2. Connecting To A Process Instead Of The User
3. Example—rz And sz Over rlogin
4. Redirecting Input And Output
5. Default Input And Output
6. Controlling Multiple Processes—kibitz
7. Combining Spawn Ids In A Single -input Or -output
8. Which Spawn Id Matched
9. Indirect Spawn Ids
10. An Extended Example—xkibitz
11. Exercises
Chapter 17 Background Processing
1. Putting Expect In The Background
2. Running Expect Without A Controlling Terminal
3. Disconnecting The Controlling Terminal
4. The fork Command
5. The disconnect Command
6. Reconnecting
7. Using kibitz From Other Expect Scripts
8. Mailing From Expect
9. A Manager For Disconnected Processes—dislocate
10. Expect As A Daemon
11. Example—Automating Gopher and Mosaic telnet Connections
12. Exercises
Chapter 18 Debugging Scripts
1. Tracing
2. Logging
3. Command Tracing
4. Variable Tracing
5. Example—Logging By Tracing
6. UNIX System Call Tracing
7. Tk And tkinspect
8. Traditional Debugging
9. Debugger Command Overview And Philosophy
10. Stepping Over Procedure Calls
11. Stepping Into Procedure Calls
12. Where Am I
13. The Current Scope
14. Moving Up And Down The Stack
15. Returning From A Procedure
16. Continuing Execution
17. Defining Breakpoints
18. Help
19. Changing Program Behavior
20. Changing Debugger Behavior
21. Exercises
Chapter 19 Expect + Tk = Expectk
1. Tk—A Brief Technical Overview
2. Expectk
3. The send Command
4. An Extended Example—tkpasswd
5. The expect Command And The Tk Event Loop
6. The expect_background Command
7. Multiple Spawn Ids In expect_background
8. Background Actions
9. Example—A Dumb Terminal Emulator
10. Example—A Smarter Terminal Emulator
11. Using The Terminal Emulator For Testing And Automation
12. Exercises
Chapter 20 Extended Examples
1. Encrypting A Directory
2. File Transfer Over telnet
3. You Have Unread News—tknewsbiff
4. Exercises
Chapter 21 Expect, C, And C++
1. Overview
2. Linking
3. Include Files
4. Ptys And Processes
5. Allocating Your Own Pty
6. Closing The Connection To The Spawned Process
7. Expect Commands
8. Regular Expression Patterns
9. Exact Matching
10. Matching A Null
11. What Characters Matched
12. When The Number Of Patterns Is Not Known In Advance
13. Expecting From Streams
14. Running In The Background
15. Handling Multiple Inputs And More On Timeouts
16. Output And Debugging Miscellany
17. Pty Trapping
18. Exercises
Chapter 22 Expect As Just Another Tcl Extension
1. Adding Expect To Another Tcl-based Program
2. Differences Between Expect And The Expect Extension In Another Program
3. Adding Extensions To Expect
4. Adding Extensions To Expectk
5. Creating Script-less Expect Programs
6. Functions And Variables In The Expect Extension
7. Exercises
Chapter 23 Miscellaneous
1. Random Numbers
2. Example—Generating Random Passwords
3. The Expect Library
4. Expect Versions
5. Timestamps
6. The time Command
7. Exercises

Appendix A Appendix—Commands and Variables
1. Commands And Flags
2. Variables

Return to Exploring Expect

Table of Contents

Chapter 1 Intro—What Is Expect?

Ouch, Those Programs Are Painful!

A Very Brief Overview

A First Script—dialback

Total Automation

Differing Behavior When Running Non-Interactively

Partial Automation

Dangerous, Unfriendly, Or Otherwise Unlikable User Interfaces

Graphical Applications

A Little More About Tcl

Job Control

Background Processes

Using Expect With Other Programs

Using Expect On UNIX

Using Expect On Other Operating Systems

Using Expect In Real Applications

Using Expect In Commercial Applications—Legalese

Obtaining Expect and the Examples

Expect And Tcl Resources

Exercises

Chapter 2 Tcl—Introduction And Overview

Everything Is A String

Quoting Conventions

Expressions

Braces—Deferring Evaluation

Control Structures

More On Expressions

Lists

More Ways To Manipulate Strings

Arrays

Indirect References

Handling Errors

Evaluating Lists As Commands

Passing By Reference

Working With Files

File I/O

Executing UNIX Commands

Environment Variables

Handling Unknown Commands

Libraries

Is There More To Tcl?

Exercises

Chapter 3 Getting Started With Expect

The send Command

The expect Command

Anchoring

What Happens When Input Does Not Match

Pattern-Action Pairs

Example—Timed Reads In The Shell

The spawn Command

The interact Command

Example—Anonymous ftp

Exercises

Chapter 4 Glob Patterns And Other Basics

The * Wildcard

More Glob Patterns

Backslashes

Handling Timeout

Handling End Of File (eof)

Hints On The spawn Command

Back To Eof

The close Command

Programs That Ignore Eof

The wait Command

Exercises

Chapter 5 Regular Expressions

Regular Expressions—A Quick Start

Identifying Regular Expressions And Glob Patterns

Using Parentheses To Override Precedence

Using Parentheses For Feedback

More On The timed–read Script

Pattern Matching Strategy

Nested Parentheses

Always Count Parentheses Even Inside Of Alternatives

Example—The Return Value From A Remote Shell

Matching Customized Prompts

Example—A Smart Remote Login Script

What Else Gets Stored In expect_out

More On Anchoring