List of Examples;Foreword;Preface; What''s in This Book; Platform Notes; Other Books; Conventions Used in This Book; We''d Like to Hear from You; Acknowledgments;Chapter 1: Strings; 1.1 Introduction; 1.2 Accessing Substrings; 1.3 Establishing a Default Value; 1.4 Exchanging Values Without Using Temporary Variables; 1.5 Converting Between ASCII Characters and Values; 1.6 Processing a String One Character at a Time; 1.7 Reversing a String by Word or Character; 1.

8 Expanding and Compressing Tabs; 1.9 Expanding Variables in User Input; 1.10 Controlling Case; 1.11 Interpolating Functions and Expressions Within Strings; 1.12 Indenting Here Documents; 1.13 Reformatting Paragraphs; 1.14 Escaping Characters; 1.15 Trimming Blanks from the Ends of a String; 1.

16 Parsing Comma-Separated Data; 1.17 Soundex Matching; 1.18 Program: fixstyle; 1.19 Program: psgrep;Chapter 2: Numbers; 2.1 Introduction; 2.2 Checking Whether a String Is a Valid Number; 2.3 Comparing Floating-Point Numbers; 2.4 Rounding Floating-Point Numbers; 2.

5 Converting Between Binary and Decimal; 2.6 Operating on a Series of Integers; 2.7 Working with Roman Numerals; 2.8 Generating Random Numbers; 2.9 Generating Different Random Numbers; 2.10 Making Numbers Even More Random; 2.11 Generating Biased Random Numbers; 2.12 Doing Trigonometry in Degrees, not Radians; 2.

13 Calculating More Trigonometric Functions; 2.14 Taking Logarithms; 2.15 Multiplying Matrices; 2.16 Using Complex Numbers; 2.17 Converting Between Octal and Hexadecimal; 2.18 Putting Commas in Numbers; 2.19 Printing Correct Plurals; 2.20 Program: Calculating Prime Factors;Chapter 3: Dates and Times; 3.

1 Introduction; 3.2 Finding Today''s Date; 3.3 Converting DMYHMS to Epoch Seconds; 3.4 Converting Epoch Seconds to DMYHMS; 3.5 Adding to or Subtracting from a Date; 3.6 Difference of Two Dates; 3.7 Day in a Week/Month/Year or Week Number; 3.8 Parsing Dates and Times from Strings; 3.

9 Printing a Date; 3.10 High-Resolution Timers; 3.11 Short Sleeps; 3.12 Program: hopdelta;Chapter 4: Arrays; 4.1 Introduction; 4.2 Specifying a List In Your Program; 4.3 Printing a List with Commas; 4.4 Changing Array Size; 4.

5 Doing Something with Every Element in a List; 4.6 Iterating Over an Array by Reference; 4.7 Extracting Unique Elements from a List; 4.8 Finding Elements in One Array but Not Another; 4.9 Computing Union, Intersection, or Difference of Unique Lists; 4.10 Appending One Array to Another; 4.11 Reversing an Array; 4.12 Processing Multiple Elements of an Array; 4.

13 Finding the First List Element That Passes a Test; 4.14 Finding All Elements in an Array Matching Certain Criteria; 4.15 Sorting an Array Numerically; 4.16 Sorting a List by Computable Field; 4.17 Implementing a Circular List; 4.18 Randomizing an Array; 4.19 Program: words; 4.20 Program: permute;Chapter 5: Hashes; 5.

1 Introduction; 5.2 Adding an Element to a Hash; 5.3 Testing for the Presence of a Key in a Hash; 5.4 Deleting from a Hash; 5.5 Traversing a Hash; 5.6 Printing a Hash; 5.7 Retrieving from a Hash in Insertion Order; 5.8 Hashes with Multiple Values Per Key; 5.

9 Inverting a Hash; 5.10 Sorting a Hash; 5.11 Merging Hashes; 5.12 Finding Common or Different Keys in Two Hashes; 5.13 Hashing References; 5.14 Presizing a Hash; 5.15 Finding the Most Common Anything; 5.16 Representing Relationships Between Data; 5.

17 Program: dutree;Chapter 6: Pattern Matching; 6.1 Introduction; 6.2 Copying and Substituting Simultaneously; 6.3 Matching Letters; 6.4 Matching Words; 6.5 Commenting Regular Expressions; 6.6 Finding the Nth Occurrence of a Match; 6.7 Matching Multiple Lines; 6.

8 Reading Records with a Pattern Separator; 6.9 Extracting a Range of Lines; 6.10 Matching Shell Globs as Regular Expressions; 6.11 Speeding Up Interpolated Matches; 6.12 Testing for a Valid Pattern; 6.13 Honoring Locale Settings in Regular Expressions; 6.14 Approximate Matching; 6.15 Matching from Where the Last Pattern Left Off; 6.

16 Greedy and Non-Greedy Matches; 6.17 Detecting Duplicate Words; 6.18 Expressing AND, OR, and NOT in a Single Pattern; 6.19 Matching Multiple-Byte Characters; 6.20 Matching a Valid Mail Address; 6.21 Matching Abbreviations; 6.22 Program: urlify; 6.23 Program: tcgrep; 6.

24 Regular Expression Grabbag;Chapter 7: File Access; 7.1 Introduction; 7.2 Opening a File; 7.3 Opening Files with Unusual Filenames; 7.4 Expanding Tildes in Filenames; 7.5 Making Perl Report Filenames in Errors; 7.6 Creating Temporary Files; 7.7 Storing Files Inside Your Program Text; 7.

8 Writing a Filter; 7.9 Modifying a File in Place with Temporary File; 7.10 Modifying a File in Place with -i Switch; 7.11 Modifying a File in Place Without a Temporary File; 7.12 Locking a File; 7.13 Flushing Output; 7.14 Reading from Many Filehandles Without Blocking; 7.15 Doing Non-Blocking I/O; 7.

16 Determining the Number of Bytes to Read; 7.17 Storing Filehandles in Variables; 7.18 Caching Open Output Filehandles; 7.19 Printing to Many Filehandles Simultaneously; 7.20 Opening and Closing File Descriptors by Number; 7.21 Copying Filehandles; 7.22 Program: netlock; 7.23 Program: lockarea;Chapter 8: File Contents; 8.

1 Introduction; 8.2 Reading Lines with Continuation Characters; 8.3 Counting Lines (or Paragraphs or Records) in a File; 8.4 Processing Every Word in a File; 8.5 Reading a File Backwards by Line or Paragraph; 8.6 Trailing a Growing File; 8.7 Picking a Random Line from a File; 8.8 Randomizing All Lines; 8.

9 Reading a Particular Line in a File; 8.10 Processing Variable-Length Text Fields; 8.11 Removing the Last Line of a File; 8.12 Processing Binary Files; 8.13 Using Random-Access I/O; 8.14 Updating a Random-Access File; 8.15 Reading a String from a Binary File; 8.16 Reading Fixed-Length Records; 8.

17 Reading Configuration Files; 8.18 Testing a File for Trustworthiness; 8.19 Program: tailwtmp; 8.20 Program: tctee; 8.21 Program: laston;Chapter 9: Directories; 9.1 Introduction; 9.2 Getting and Setting Timestamps; 9.3 Deleting a File; 9.

4 Copying or Moving a File; 9.5 Recognizing Two Names for the Same File; 9.6 Processing All Files in a Directory; 9.7 Globbing, or Getting a List of Filenames Matching a Pattern; 9.8 Processing All Files in a Directory Recursively; 9.9 Removing a Directory and Its Contents; 9.10 Renaming Files; 9.11 Splitting a Filename into Its Component Parts; 9.

12 Program: symirror; 9.13 Program: lst;Chapter 10: Subroutines; 10.1 Introduction; 10.2 Accessing Subroutine Arguments; 10.3 Making Variables Private to a Function; 10.4 Creating Persistent Private Variables; 10.5 Determining Current Function Name; 10.6 Passing Arrays and Hashes by Reference; 10.

7 Detecting Return Context; 10.8 Passing by Named Parameter; 10.9 Skipping Selected Return Values; 10.10 Returning More Than One Array or Hash; 10.11 Returning Failure; 10.12 Prototyping Functions; 10.13 Handling Exceptions; 10.14 Saving Global Values; 10.

15 Redefining a Function; 10.16 Trapping Undefined Function Calls with AUTOLOAD; 10.17 Nesting Subroutines; 10.18 Program: Sorting Your Mail;Chapter 11: References and Records; 11.1 Introduction; 11.2 Taking References to Arrays; 11.3 Making Hashes of Arrays; 11.4 Taking References to Hashes; 11.

5 Taking References to Functions; 11.6 Taking References to Scalars; 11.7 Creating Arrays of Scalar References; 11.8 Using Closures Instead of Objects; 11.9 Creating References to Methods; 11.10 Constructing Records; 11.11 Reading and Writing Hash Records to Text Files; 11.12 Printing Data Structures; 11.

13 Copying Data Structures; 11.14 Storing Data Structures to Disk; 11.15 Transparently Persistent Data Structures; 11.16 Program: Binary Trees;Chapter 12: Packages, Libraries, and Modules; 12.1 Introduction; 12.2 Defining a Module''s Interface; 12.3 Trapping Errors in require or use; 12.4 Delaying use Until Run Time; 12.

5 Making Variables Private to a Module; 12.6 Determining the Caller''s Package; 12.7 Automating Module Clean-Up; 12.8 Keeping Your Own Module Directory; 12.9 Preparing a Module for Distribution; 12.10 Speeding Module Loading with SelfLoader; 12.11 Speeding Up Module Loading with Autoloader; 12.12 Overriding Built-In Functions; 12.

13 Reporting Errors and Warnings Like Built-Ins; 12.14 Referring to Packages Indirectly; 12.15 Using h2ph to Translate C #include Files; 12.16 Using h2xs to Make a Module with C Code; 12.17 Documenting Your Module with Pod; 12.18 Building and Installing a CPAN Module; 12.19 Example: Module Template; 12.20 Program: Finding Versions and Descriptions of Installed Modules;Chapter 13: Classes, Objects, and Ties; 13.

1 Introduction; 13.2 Constructing an Object; 13.3 Destroying an Object; 13.4 Managing Instance Data; 13.5 Managing Class Data; 13.6 Using Classes as Structs; 13.7 Cloning Objects; 13.8 Calling Methods Indirectly; 13.

9 Determining Subclass Membership; 13.10 Writing an Inheritable Class; 13.11 Accessing Overridden Methods; 13.12 Generating Attribute Methods Using AUTOLOAD; 13.13 Solving the Data Inheritance Problem; 13.14 Coping with Circular Data Structures; 13.15 Overloading Operators; 13.16 Creating Magic Variables with tie;Chapter 14: Database Access; 14.

1 Introduction; 14.2 Making and Using a DBM File; 14.3 Emptying a DBM File; 14.4 Converting Between DBM Files; 14.5 Merging DBM Files; 14.6 Locking DBM Files; 14.7 Sorting Large DBM Files; 14.8 Treating a Text File as a Database Array; 14.

9 Storing Complex Data in a DBM File; 14.10 Persistent Data; 14.11 Executing an SQL Command Using DBI and DBD; 14.12 Program: ggh--Grep Netscape Global History;Chapter 15: User Interfaces; 15.1 Introduction; 15.2 Parsing Program Arguments; 15.3 Testing Whether a Program Is Running Interactively; 15.4 Clearing the Screen; 15.

5 Determining Terminal or Window Size; 15.6 Changing Text Color; 15.7 Reading from the Keyboard; 15.8 Ringing the Terminal Bell; 15.9 Using POSIX termios; 15.10 Checking for Waiting Input; 15.11 Reading Passwords; 15.12 Editing Input; 15.

13 Managing the Screen; 15.14 Controlling Another Program with Expect; 15.15 Creating Men.