Index: R
- race conditions : Writing a Safe CGI Program
- rad2deg( ) (example) : Doing Trigonometry in Degrees, not Radians
- radians vs. degrees : Doing Trigonometry in Degrees, not Radians
- radiobuttons : Creating Menus with Tk
- rand( )
- randcap program (example) : Controlling Case
- random
-
- email signatures : Program: sigrand
- lines from files : Picking a Random Line from a File
- numbers
- ordering of lines in files : Randomizing All Lines
- random-access I/O : Using Random-Access I/O
- randomizing arrays : Randomizing an Array
- range (.. and ...) operators : Extracting a Range of Lines
- read( )
- readdir( )
- reading email : (see email)
- reading files : (see file access; file contents)
- reading input : (see input)
- reading Usenet news : Reading and Posting Usenet News Messages
- Received: header line : Program: hopdelta
- recno_demo program (example) : Treating a Text File as a Database Array
- records : Introduction
-
- binary tree structures : Program: Binary Trees
- closures as objects : Using Closures Instead of Objects
- comma-separated : (see CSV)
- constructing : Constructing Records
- counting in files : Counting Lines (or Paragraphs or Records) in a File
- fixed-length
- lastlog file : Program: laston
- with pattern separators, reading : Reading Records with a Pattern Separator
- random-access I/O : Using Random-Access I/O
- reading/writing to text files : Reading and Writing Hash Records to Text Files
- variable-length : Processing Variable-Length Text Fields
- wtmp file : Program: tailwtmp
- recursively processing files in directories : Processing All Files in a Directory Recursively
- redirect( ) : Redirecting to a Different Location
- redirecting
-
- CGI error messages : Redirecting Error Messages
- CGI requests : Redirecting to a Different Location
- ref( )
- references : Introduction
-
- to arrays : Taking References to Arrays
- arrays of scalar references : Creating Arrays of Scalar References
- as hash keys : Creating Magic Variables with tie
- autovivification : Introduction
- closures as objects : Using Closures Instead of Objects
- to functions : Taking References to Functions
- as hash values : Hashing References
- to hashes : Taking References to Hashes
- hashes of arrays : Making Hashes of Arrays
- iterating over arrays by : Iterating Over an Array by Reference
- to methods : Creating References to Methods
- to packages, indirect : Referring to Packages Indirectly
- passing by : Passing Arrays and Hashes by Reference
- reference count : Introduction
- returning by : Returning More Than One Array or Hash
- to scalars : Taking References to Scalars
- self-referential structures : Coping with Circular Data Structures
- symbolic
- referents : Introduction
- "referrer" vs. "referer" : Fetching a URL from a Perl Script
- regular expressions
-
- (see also pattern matching)
- Soundex Matching
- checking if strings are valid numbers : Checking Whether a String Is a Valid Number
- commenting : Commenting Regular Expressions
- fuzzy matching : Approximate Matching
- honoring locale settings : Honoring Locale Settings in Regular Expressions
- multiple-byte matching : Matching Multiple-Byte Characters
- tcgrep program : Program: tcgrep
- testing for invalid patterns : Testing for a Valid Pattern
- urlify program : Program: urlify
- useful and interesting (list) : Regular Expression Grabbag
- removing HTML tags : Extracting or Removing HTML Tags
- rename script (example) : Renaming Files
- renaming files : Renaming Files
- rep program (example) : Managing the Screen
- reporting errors : (see errors; warnings)
- require statement : Introduction
-
- trapping errors in : Trapping Errors in require or use
- resizing : (see size)
- restarting servers on demand : Restarting a Server on Demand
- retrieve( ) (Storable module) : Storing Data Structures to Disk
- retrieving URLs : Fetching a URL from a Perl Script
- return context, subroutines : Detecting Return Context
- return statement : Returning Failure
- return values of subroutines
-
- returning by reference : Returning More Than One Array or Hash
- returning failure : Returning Failure
- skipping selected : Skipping Selected Return Values
- reverse( )
-
- Reversing a String by Word or Character
- Reversing an Array
- inverting hashes : Inverting a Hash
- reversing
-
- array elements : Reversing an Array
- words/characters in strings : Reversing a String by Word or Character
- revhash_demo program (example) : Creating Magic Variables with tie
- rewinddir( ) : Processing All Files in a Directory
- rmdir( ) : Removing a Directory and Its Contents
- rmtree program (example) : Removing a Directory and Its Contents
- robots for web traversal : Creating a Robot
- Roman module : Working with Roman Numerals
- roman numerals : Working with Roman Numerals
- roman( ) (Roman module) : Working with Roman Numerals
- root directory (/) : Introduction
- rounding floating-point numbers : Rounding Floating-Point Numbers
- run time, loading modules at : Delaying use Until Run Time
- run-time scoping : Saving Global Values
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