Index: S

• /s pattern-matching modifier : Introduction
• • matching multiple lines : Matching Multiple Lines
• substitution modifier : Indenting Here Documents
• s/// operator
• • ~ operator with : Accessing Substrings
  • stripping whitespace with : Indenting Here Documents
• sascii program (example) : Reading from the Keyboard
• save_parameters( ) : Saving a Form to a File or Mail Pipe
• scalars : Introduction
• • arrays of scalar references : Creating Arrays of Scalar References
  • detecting scalar context : Detecting Return Context
  • exchanging values between : Exchanging Values Without Using Temporary Variables
  • references to : Taking References to Scalars
• schemes (URLs) : Introduction
• Schwartz, Randal : Sorting a List by Computable Field
• scope of subroutine variables : Making Variables Private to a Function
• screen : (see user interfaces)
• scripts, CGI : (see CGI developing)
• SDBM library : Introduction
• searching for patterns : (see pattern matching; regular expressions)
• seconds : (see date and time)
• security
• • CGI scripts
  • • Introduction
    • Writing a Safe CGI Program
    • executing user commands : Executing Commands Without Shell Escapes
  • connecting through firewalls : Program: fwdport
  • reading passwords without echo : Reading Passwords
  • testing files for trustworthiness : Testing a File for Trustworthiness
• seek( )
• • Introduction
  • Trailing a Growing File
• seekdir( ) : Processing All Files in a Directory
• seeme program (example) : Flushing Output
• select( )
• • Short Sleeps
  • Communicating over TCP
  • changing STDOUT : Introduction
  • reading from multiple filehandles
  • • Reading from Many Filehandles Without Blocking
    • Communicating over TCP
• self-referential data structures : Coping with Circular Data Structures
• SelfLoader module : Speeding Module Loading with SelfLoader
• separators, menu : Creating Menus with Tk
• servers
• • daemon servers : Making a Daemon Server
  • forking : Forking Servers
  • multi-homed : Writing a Multi-Homed Server
  • non-forking : Non-Forking Servers
  • POP3 : Reading Mail with POP3
  • pre-forking : Pre-Forking Servers
  • restarting on demand : Restarting a Server on Demand
  • TCP : Writing a TCP Server
  • UDP : Setting Up a UDP Server
• set theory : Finding Elements in One Array but Not Another
• setsockopt( ) : Non-Forking Servers
• setting up : (see initializing)
• shallow copies : Copying Data Structures
• shared locks : Locking a File
• sharetest program (example) : Sharing Variables in Different Processes
• sharing variables among processes : Sharing Variables in Different Processes
• shell escapes, executing commands without : Executing Commands Without Shell Escapes
• shell wildcards for regexp matching : Matching Shell Globs as Regular Expressions
• shift( )
• • circular lists : Implementing a Circular List
  • on multiple array elements : Processing Multiple Elements of an Array
  • Tie::IxHash module and : Retrieving from a Hash in Insertion Order
• shopping cart : Writing a Multiscreen CGI Script
• shuffling
• • (see also random)
  • Randomizing All Lines
  • array elements : Randomizing an Array
  • file line order : Randomizing All Lines
• shutdown( ) : Closing a Socket After Forking
• %SIG hash : Installing a Signal Handler
• SIGALRM signal
• • Introduction
  • Timing Out an Operation
• SIGCHLD signal
• • Introduction
  • Avoiding Zombie Processes
• SIGHUP signal
• • Introduction
  • Restarting a Server on Demand
• SIGINT signal
• • Introduction
  • Catching Ctrl-C
• signals : Introduction
• • blocking : Blocking Signals
  • handlers for : Installing a Signal Handler
  • listing available : Listing Available Signals
  • process groups
  • • Program: lockarea
    • Sending a Signal
  • sending : Sending a Signal
• signatures, randomized : Program: sigrand
• SIGPIPE signal
• • Introduction
  • Reading or Writing to Another Program
• sigprocmask system call : Blocking Signals
• SIGQUIT signal : Introduction
• sigrand program (example) : Program: sigrand
• SIGTERM signal : Introduction
• SIGUSR1, SIGUSR2 signals : Introduction
• sin( ) : Calculating More Trigonometric Functions
• single inheritance : Introduction
• single quotes (') : Introduction
• • q( ) : Specifying a List In Your Program
• size
• • arrays, changing : Changing Array Size
  • hashes, preallocating for : Presizing a Hash
  • Tk window resize events : Responding to Tk Resize Events
  • window/terminal, determining : Determining Terminal or Window Size
• sleeps : Short Sleeps
• slowcat program (example) : Processing a String One Character at a Time
• SOCK_ constants : Introduction
• sockaddr_in( )
• • Introduction
  • Setting Up a UDP Client
• sockaddr_un( ) : Introduction
• socket( ) : Introduction
• sockets : Introduction
• • bidirectional clients : Writing Bidirectional Clients
  • closing after forking : Closing a Socket After Forking
  • connecting through firewalls : Program: fwdport
  • daemon servers : Making a Daemon Server
  • finding own name/address : Finding Your Own Name and Address
  • forking servers : Forking Servers
  • identifying machine at end : Identifying the Other End of a Socket
  • logging port connection attempts : Program: backsniff
  • multi-homed servers : Writing a Multi-Homed Server
  • non-blocking : Writing a TCP Server
  • non-forking servers : Non-Forking Servers
  • pre-forking servers : Pre-Forking Servers
  • restarting servers on demand : Restarting a Server on Demand
  • TCP protocol
  • • communicating over : Communicating over TCP
    • writing clients : Writing a TCP Client
    • writing servers : Writing a TCP Server
  • UDP protocol
  • • writing clients : Setting Up a UDP Client
    • writing servers : Setting Up a UDP Server
  • Unix domain
  • • Introduction
    • Using UNIX Domain Sockets
• soft links : (see symbolic links)
• sort( )
• • Sorting an Array Numerically
  • Sorting a Hash
• sortdemo program (example) : Sorting Large DBM Files
• sorting
• • array elements : Sorting an Array Numerically
  • DBM files : Sorting Large DBM Files
  • directory contents
  • • Introduction
    • Program: lst
  • du command output : Program: dutree
  • hash elements : Sorting a Hash
  • mail (example subroutine) : Program: Sorting Your Mail
  • pod =head1 sections : Program: tkshufflepod
  • randomizing array element order : Randomizing an Array
  • randomizing file line order : Randomizing All Lines
  • text into columns : Program: words
• Soundex matching : Soundex Matching
• spaces : (see whitespace)
• specific classes : Introduction
• spider (robot) : Creating a Robot
• splice( ) : Processing Multiple Elements of an Array
• • Tie::IxHash module and : Retrieving from a Hash in Insertion Order
• split( )
• • Processing a String One Character at a Time
  • Processing Every Word in a File
  • Processing Variable-Length Text Fields
  • reading records with pattern separators : Reading Records with a Pattern Separator
• sprintf( )
• • %c format : Converting Between ASCII Characters and Values
  • comparing floating-point numbers : Comparing Floating-Point Numbers
  • rounding floating-point numbers : Rounding Floating-Point Numbers
• SQL database : Creating HTML Templates
• SQL queries
• • Executing an SQL Command Using DBI and DBD
  • Formatting Lists and Tables with HTML Shortcuts
• srand( ) : Generating Different Random Numbers
• stale hyperlinks, finding : Finding Stale Links
• standard filehandles : Introduction
• stat( )
• • Testing a File for Trustworthiness
  • Introduction
  • Getting and Setting Timestamps
• static data members
• • Introduction
  • Managing Class Data
• static scoping : Saving Global Values
• STDERR filehandle : Introduction
• • controlling for other programs : Controlling the Input, Output, and Error of Another Program
  • reading from programs : Reading STDERR from a Program
• STDIN filehandle : Introduction
• • preprocessing input : Preprocessing Input
  • testing for interactivity : Testing Whether a Program Is Running Interactively
• stdio library : Introduction
• STDOUT filehandle : Introduction
• • filtering output : Filtering Your Own Output
  • testing for interactivity : Testing Whether a Program Is Running Interactively
• sticky widgets : Creating Sticky Widgets
• stingy matching : (see non-greedy pattern matching)
• Storable module : Copying Data Structures
• STORE( ) : Creating Magic Variables with tie
• store( ) (Storable module) : Storing Data Structures to Disk
• stream sockets
• • Introduction
  • Forking Servers
• strftime( ) : Printing a Date
• String::Approx module : Approximate Matching
• strings
• • (see also variables)
  • Introduction
  • Expanding Variables in User Input
  • accessing substrings : Accessing Substrings
  • checking if valid numbers : Checking Whether a String Is a Valid Number
  • converting ASCII and values : Converting Between ASCII Characters and Values
  • converting ASCII to/from HTML : Converting ASCII to HTML
  • converting case : Controlling Case
  • copying and substituting : Copying and Substituting Simultaneously
  • default values for : Establishing a Default Value
  • duplicate words, finding : Detecting Duplicate Words
  • escaping characters : Escaping Characters
  • hash element indices : Introduction
  • HTML text substitutions : Program: htmlsub
  • interpolating functions/expression within : Interpolating Functions and Expressions Within Strings
  • matching letters : Matching Letters
  • matching words : Matching Words
  • numeric operators with : Overloading Operators
  • parsing datetime information in : Parsing Dates and Times from Strings
  • plurals based on numbers : Printing Correct Plurals
  • processing characters individually : Processing a String One Character at a Time
  • psgrep program (example) : Program: psgrep
  • reading from binary files : Reading a String from a Binary File
  • reformatting paragraphs : Reformatting Paragraphs
  • removing leading/trailing spaces : Trimming Blanks from the Ends of a String
  • removing/extracting HTML tags : Extracting or Removing HTML Tags
  • reversing elements of : Reversing a String by Word or Character
  • substituting specific words : Program: fixstyle
  • text color, changing : Changing Text Color
• strings program (example) : Reading a String from a Binary File
• stripping whitespace : Trimming Blanks from the Ends of a String
• StrNum class (example) : Overloading Operators
• struct( ) (Class::Struct) : Using Classes as Structs
• struct_flock( ) (lockarea) : Program: lockarea
• structs, classes as : Using Classes as Structs
• sub keyword : Introduction
• subclasses : Introduction
• • determining membership : Determining Subclass Membership
  • inheritance and : Solving the Data Inheritance Problem
• subject, sorting mail by (example) : Program: Sorting Your Mail
• submitting HTML forms : Automating Form Submission
• subroutines : Introduction
• • access arguments of : Accessing Subroutine Arguments
  • built-in, overriding : Overriding Built-In Functions
  • currently running, name of : Determining Current Function Name
  • email sorter (example) : Program: Sorting Your Mail
  • exception handling : Handling Exceptions
  • localizing : Redefining a Function
  • nesting : Nesting Subroutines
  • passing by named parameter : Passing by Named Parameter
  • passing by reference : Passing Arrays and Hashes by Reference
  • private for modules : Making Variables Private to a Module
  • private variables : Making Variables Private to a Function
  • prototypes for functions : Prototyping Functions
  • return context, detecting : Detecting Return Context
  • return values
  • • returning by reference : Returning More Than One Array or Hash
    • returning failure : Returning Failure
    • skipping selected : Skipping Selected Return Values
  • saving global values : Saving Global Values
  • trapping undefined function calls : Trapping Undefined Function Calls with AUTOLOAD
• substituting within strings : Copying and Substituting Simultaneously
• substr( ) : Accessing Substrings
• substrings : Accessing Substrings
• SUPER class : Accessing Overridden Methods
• superclasses : Introduction
• • accessing overridden methods : Accessing Overridden Methods
  • inheritance and : Solving the Data Inheritance Problem
• surface copies : Copying Data Structures
• surl script : Finding Fresh Links
• switch statement
• • Redirecting to a Different Location
  • Writing a Multiscreen CGI Script
• Symbol::qualify( ) : Determining the Caller's Package
• symbolic links : Introduction
• • duplicating directory trees : Program: symirror
  • to packages : Referring to Packages Indirectly
• symirror program (example) : Program: symirror
• symmetric differences of lists : Computing Union, Intersection, or Difference of Unique Lists
• Sys::Hostname module : Finding Your Own Name and Address
• Sys::Syslog module : Program: backsniff
• syscall( ) : High-Resolution Timers
• sysopen( ) : Opening a File
• • strange filenames with : Opening Files with Unusual Filenames
• sysread( )
• • Introduction
  • Introduction
• sysseek( ) : Introduction
• system( )
• • Running Another Program
  • Executing Commands Without Shell Escapes
• SysV IPC : Sharing Variables in Different Processes
• syswrite( )
• • Introduction
  • Introduction