Symbols | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Explanatory note

U

-u file test operator : Named Unary and File Test Operators
-U switch, perl : Switches
-u switch, perl : Switches
uc function : uc
ucfirst function : ucfirst
UDP communications : UDP: message passing
$UID (see $<; variable)
uid (user ID) (see also $<; variable; $>; variable) chown assumed : Talking to yourself passwd file entry from : getpwuid
$uid file statistic : stat
umask function : umask
unary operators Calling conventions for unary operations Overloadable operations arithmetic : Autoincrement and Autodecrement Operators glob operator as : Filename globbing operator ideographic : Ideographic Unary Operators named Filename globbing operator Named Unary and File Test Operators
unbuffered input : getc
undef (value) : defined
undef function undef Time Efficiency
undefined scalars : Scalar Values Boolean context and : Boolean context
underscore (see _)
unequal (see equality operators; relational operators)
uninitialized variables : Singularities
uninstall( ) : ExtUtils::Install--Install Files from Here to There
UNIVERSAL class : A Class Is Simply a Package
UNIX clients/servers : UNIX-domain clients and servers security bugs : Security bugs
unless statement (see if statement)
unlink function : unlink
unlinking (see deleting)
unordered lists (see hashes)
unpack function : unpack
unsafe operations : Switches
unshift function : unshift
untie function dbmclose untie Using Tied Variables
until statement (see while loop)
use declarations (see pragmas) use strict : Frequently Ignored Advice use vars pragma : AutoLoader--Load Functions Only on Demand
user CPU times : times
user CPU time : Notes
user efficiency : User Efficiency
user ID (see uid)
user-defined functions (see subroutines)
username passwd file entry from : getpwnam
"uses" relationship : Implementation (the "Uses" Relationship)
utime function : utime
utmp file (see /etc/utmp file) Symbols | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z Explanatory note Copyright © 1997 O'Reilly & Associates, Inc. All Rights Reserved.