Index: U

• string escape : Controlling Case
• string escape : Controlling Case
• uc( ) : Controlling Case
• ucfirst( ) : Controlling Case
• UDP protocol
• • writing clients : Setting Up a UDP Client
  • writing servers : Setting Up a UDP Server
• udpmsg program (example) : Setting Up a UDP Server
• udpqotd program (example) : Setting Up a UDP Server
• umask values : Opening a File
• uname( ) (POSIX) : Finding Your Own Name and Address
• unbuffered input/output
• • Introduction
  • Flushing Output
  • Introduction
  • Reading from the Keyboard
• uncontrol subroutine : Using POSIX termios
• undef( ) : Introduction
• undefined (undef) value : Introduction
• Unicode : Introduction
• unimport( )
• • Program: psgrep
  • Creating Magic Variables with tie
• unions of lists : Finding Elements in One Array but Not Another
• unique list elements, extracting : Extracting Unique Elements from a List
• UNIVERSAL package : Determining Subclass Membership
• Unix domain sockets
• • Introduction
  • Using UNIX Domain Sockets
• UnixDate( ) : Parsing Dates and Times from Strings
• unlink( )
• • Deleting a File
  • Removing a Directory and Its Contents
• unpack( )
• • Accessing Substrings
  • Converting Between ASCII Characters and Values
  • Reading Fixed-Length Records
  • converting binary and decimal numbers : Converting Between Binary and Decimal
• unshift( )
• • circular lists : Implementing a Circular List
  • Tie::IxHash module and : Retrieving from a Hash in Insertion Order
• untie( ) : Making and Using a DBM File
• uppercase, converting to lowercase : Controlling Case
• URI::Heuristic : Finding Stale Links
• urlify program : Program: urlify
• URLs (Uniform Resource Locators) : Introduction
• • extracting from HTML : Extracting URLs
  • fetching from Perl scripts : Fetching a URL from a Perl Script
  • putting HTML links around : Program: urlify
  • redirecting CGI requests : Redirecting to a Different Location
• use pragmas : Introduction
• • trapping errors in : Trapping Errors in require or use
  • use autouse pragma : Delaying use Until Run Time
  • use lib pragma : Keeping Your Own Module Directory
  • use locale pragma
  • • Controlling Case
    • Introduction
    • Honoring Locale Settings in Regular Expressions
  • use overload pragma : Overloading Operators
• Usenet news : Reading and Posting Usenet News Messages
• user input : (see input)
• user interfaces : Introduction
• • checking for waiting input : Checking for Waiting Input
  • clearing the screen : Clearing the Screen
  • controlling programs with Expect : Controlling Another Program with Expect
  • determining window size : Determining Terminal or Window Size
  • dialog boxes with Tk : Creating Dialog Boxes with Tk
  • editing input : Editing Input
  • full-screen mode : Introduction
  • managing screen : Managing the Screen
  • manipulating terminal directly : Using POSIX termios
  • menus with Tk : Creating Menus with Tk
  • multiscreen CGI scripts : Writing a Multiscreen CGI Script
  • parsing command-line options : Parsing Program Arguments
  • reading from keyboard : Reading from the Keyboard
  • reading passwords without echo : Reading Passwords
  • removing DOS shell window : Removing the DOS Shell Window with Windows Perl/Tk
  • ringing terminal bell : Ringing the Terminal Bell
  • tcapdemo program : Program: Small termcap program
  • testing programs if running interactively : Testing Whether a Program Is Running Interactively
  • text color : Changing Text Color
  • Tk resize events : Responding to Tk Resize Events
• userstats program (example) : Making and Using a DBM File
• utime( ) : Getting and Setting Timestamps
• uvi program (example) : Getting and Setting Timestamps