Index

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

# Symbols and Numbers

-0 switch, perl : Switches
& (ampersand) : Named Unary and File Test Operators

address-of operator (in C) : C Operators Missing from Perl
bitwise AND operator : Bitwise Operators
in filenames : open
prototype character : Prototypes
for subroutine names

Variables
Subroutines

&& (AND) operator : C-style Logical (Short Circuit) Operators
&&= (assignment) operator : Assignment Operators
&= (assignment) operator : Assignment Operators

* (asterisk) : Named Unary and File Test Operators

dereference operator (in C) : C Operators Missing from Perl
multiplicative operator : Multiplicative Operators
prototype character : Prototypes
quantifier

Quantifiers
The rules of regular expression matching

for typeglob names

Typeglobs and Filehandles
Passing Symbol Table Entries (Typeglobs)

** (exponentiation) operator : Exponentiation
**= (assignment) operator : Assignment Operators
*= (assignment) operator : Assignment Operators

@ (at sign) : Previous Perl Traps

for array names : Variables
in debugger : Using the Debugger
in picture lines : Formats
prototype character : Prototypes
@_ array

Subroutines
English--Use English or awk Names for Punctuation Variables
Debugger Bugs

\ (backslash)

to escape metacharacters : The regular expression bestiary
for multiline commands : Using the Debugger
quotemeta function for : quotemeta
reference operator

Ideographic Unary Operators
The Backslash Operator

` (backtick) : Anonymous pipes

emulating : Cleaning up your path
operator

Command input (backtick) operator
Shell Traps
Programming with Style

! (bang)

for argument specifiers : Getopt::Long--Extended Processing of Command-Line Options
debugger command : Debugger Commands
in import list : Specialized import lists
logical negation operator : Ideographic Unary Operators
!! debugger command : Debugger Commands
!= (not equal to) operator

Equality Operators
Universal Blunders

!~ (binding) operator : Binding Operators

{ } (braces)

Braces, Brackets, and Quoting
Universal Blunders
Programming with Style
in awk : Awk Traps
for statement blocks : Compound Statements
hash composer : The Anonymous Hash Composer
identifiers in : String literals
quantifier

Quantifiers
The rules of regular expression matching

[ ] (brackets)

array composer : The Anonymous Array Composer
to match characters : The rules of regular expression matching

^ (caret)

assertion : Quantifiers
bitwise XOR operator

Bitwise Operators
Awk Traps

line boundary

Nailing Things Down
The rules of regular expression matching
The fine print

matching : The rules of regular expression matching
in picture lines : Formats
^= (assignment) operator : Assignment Operators

: (colon)

in import list : Specialized import lists
:: for package identifiers

Packages
Previous Perl Traps

, (comma) : Universal Blunders

delimiting list values : List Values and Arrays
key/value pairs and : Hashes (Associative Arrays)
large numbers and : Numeric literals
operator

Comma Operators
Awk Traps

$ (dollar sign)

for backreferences (see backreferences)
in debugger : Using the Debugger
line boundary

The rules of regular expression matching
The fine print

prototype character : Prototypes
for scalar variable names : Variables
word boundary : Nailing Things Down
$# prefix : List Values and Arrays

$ variables

$0 ($PROGRAM_NAME)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$1, $2, $3... (see backreferences)
$& ($MATCH)

The fine print
Regular Expression Special Variables
a2p
English--Use English or awk Names for Punctuation Variables
Time Efficiency

$' ($POSTMATCH)

The fine print
Regular Expression Special Variables
a2p
English--Use English or awk Names for Punctuation Variables
Time Efficiency

$* ($MULTILINE_MATCHING) : Regular Expression Special Variables
$@ ($EVAL_ERROR)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$\ ($OUTPUT_RECORD_SEPARATOR)

Global Special Variables
Switches
English--Use English or awk Names for Punctuation Variables

$` ($PREMATCH)

The fine print
Regular Expression Special Variables
a2p
English--Use English or awk Names for Punctuation Variables
Time Efficiency

$! ($OS_ERROR)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$[ : Global Special Variables
$] ($PERL_VERSION)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^ ($FORMAT_TOP_NAME)

Format Variables
Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables
Universal Blunders

$^A ($ACCUMULATOR)

Accessing Formatting Internals
Global Special Variables
English--Use English or awk Names for Punctuation Variables
formline function : formline

$^D ($DEBUGGING)

Global Special Variables
Switches
English--Use English or awk Names for Punctuation Variables

$^F ($SYSTEM_FD_MAX)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^H : Global Special Variables
$^I ($INPLACE_EDIT)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^L ($FORMAT_LINEFEED)

Format Variables
Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^O ($OSNAME)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^P ($PERLDB)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^T ($BASETIME)

Named Unary and File Test Operators
Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^W ($WARNING)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$^X ($EXECUTABLE_NAME)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$: ($FORMAT_LINE_BREAK _CHARACTERS)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$, ($OUTPUT_FIELD_SEPARATOR)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$$ ($PROCESS_ID)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$. ($INPUT_LINE_NUMBER)

Global Special Variables
English--Use English or awk Names for Punctuation Variables
resetting with close function : close

$= ($FORMAT_LINES_PER_PAGE)

Format Variables
Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables

$- ($FORMAT_LINES_LEFT)

Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables

$< ($REAL_USER_ID)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$( ($REAL_GROUP_ID)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$) ($EFFECTIVE_GROUP_ID)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$% ($FORMAT_PAGE_NUMBER)

Format Variables
Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables

$+ ($LAST_PAREN_MATCH)

The fine print
Regular Expression Special Variables
English--Use English or awk Names for Punctuation Variables

$? ($CHILD_ERROR)

Global Special Variables
English--Use English or awk Names for Punctuation Variables
backtick operator and : Command input (backtick) operator
close function and : close

$" ($LIST_SEPARATOR) : English--Use English or awk Names for Punctuation Variables
$> ($EFFECTIVE_USER_ID)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$; ($SUBSCRIPT_SEPARATOR)

Global Special Variables
English--Use English or awk Names for Punctuation Variables

$# ($OFMT) : Global Special Variables
$/ ($INPUT_RECORD_SEPARATOR)

Global Special Variables
Switches
English--Use English or awk Names for Punctuation Variables

$~ ($FORMAT_NAME)

Format Variables
Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables

$_ ($ARG)

The fine print
Global Special Variables
English--Use English or awk Names for Punctuation Variables
angle operator and : Line input (angle) operator
forearch statement and : Foreach loops
glob function with : Filename globbing operator
grep function and : grep
map function and : map

$| ($OUTPUT_AUTOFLUSH)

Format Variables
Per-Filehandle Special Variables
English--Use English or awk Names for Punctuation Variables

. (dot) : Named Unary and File Test Operators

character wildcard

Regular Expressions
The rules of regular expression matching
The fine print

concatenation operator

String Operators
Additive Operators
Time Efficiency

debugger command : Debugger Commands
.. (range) operator : Range Operator
.= (assignment) operator : Assignment Operators

= (equal sign)

assignment operator

Assignment Operators
Assignment Operators

copy constructor : Copy constructor
debugger command : Debugger Commands
sortas="@equalright">=> (corresponds to) operator : Comma Operators
= = (equal to) operator

Equality Operators
Universal Blunders

=> (corresponds to) operator

with key/value pairs : Hashes (Associative Arrays)
with named parameters : Hashes (Associative Arrays)

=~ (binding) operator : Binding Operators

- (hyphen)

The rules of regular expression matching
Named Unary and File Test Operators
arithmetic negation operator : Ideographic Unary Operators
debugger command : Debugger Commands
subtractive operator : Additive Operators
-*- for Emacs : Command Processing
-= (assignment) operator : Assignment Operators
- - (autodecrement) operator

Autoincrement and Autodecrement Operators
Autoincrement and Autodecrement
Switches
Overloadable operations

-> (arrow) operator

The Arrow Operator
Using the Arrow Operator
Object-Oriented Scaling Tips

-| piping pseudo-command : Talking to yourself

< (left angle bracket)

debugger command : Debugger Commands
for filename globbing operator : Filename globbing operator
in filenames : open
for left justification : Format Variables
less than operator : Relational Operators
for line input operator : Line input (angle) operator
<= (less than or equal) operator : Relational Operators
<=> (comparison) operator

Equality Operators
sort

<< for here documents

"Here" documents
Shift Operators

<<= (assignment) operator : Assignment Operators
< > construct (see angle operator)

Non-option callback routine

<FH> operator : Frequently Ignored Advice

( ) (parentheses)

The regular expression bestiary
Operators
Terms and List Operators (Leftward)
Programming with Style
for backreferences : Backreferences
in functions : Functions
grouping operator : The rules of regular expression matching
for list values : List Values and Arrays
(?!) assertion : Regular expression extensions
(?!...) assertion : The rules of regular expression matching
(?:) for grouping : Regular expression extensions
(?...) assertion : The rules of regular expression matching
(?=) assertion : Regular expression extensions
(?i) modifier : Regular expression extensions
(?#) for comments : Regular expression extensions

% (percent sign) : Named Unary and File Test Operators

for checksums : unpack
for hash names : Variables
modulus operator : Multiplicative Operators
prototype character : Prototypes
%= (assignment) operator : Assignment Operators

+ (plus) : Named Unary and File Test Operators

additive operator : Additive Operators
in filenames : open
quantifier

Regular Expressions
The rules of regular expression matching

unary operator : Ideographic Unary Operators
+= (assignment) operator : Assignment Operators
++ (autoincrement) operator

Autoincrement and Autodecrement Operators
Autoincrement and Autodecrement
Overloadable operations

? (question mark) : Named Unary and File Test Operators

debugger command : Debugger Commands
quantifier

Quantifiers
The rules of regular expression matching

?: (conditional) operator : Conditional Operator
?? operator (see m?? operator)

' (single quotes) : String literals
" (double quotes)

String literals
The regular expression bestiary
in formline arguments : formline

> (right angle bracket)

debugger command : Debugger Commands
for filename globbing operator : Filename globbing operator
in filenames : open
greater than operator : Relational Operators
for line input operator : Line input (angle) operator
for right justification : Format Variables
>= (greater than or equal) operator : Relational Operators
>> (right-shift) operator : Shift Operators
>>= (assignment) operator : Assignment Operators

; (semicolon)

Simple Statements
Universal Blunders

# (sharp)

for comments : Pattern Matching
in formats : Formats
#! (shebang) notation

How to Do It
Command Processing
Security bugs

/ (slash) : Named Unary and File Test Operators

debugger command : Debugger Commands
division operator : Multiplicative Operators
in import list : Specialized import lists
root directory : chroot
/= (assignment) operator : Assignment Operators
// operator (see match operator)

~ (tilde)

bitwise negation operator : Ideographic Unary Operators
complement operator : Awk Traps
to supress blank lines : Formats

_ (underscore)

Variables
Previous Perl Traps
global filehandle : Global Special Filehandles
large numbers and : Numeric literals
in variable names : Programming with Style

| (vertical bar)

for alternation : The regular expression bestiary
bitwise OR operator : Bitwise Operators
for centering : Format Variables
debugger command : Debugger Commands
in filenames : open
for option speficiers : Aliases and abbreviations
|= (assignment) operator : Assignment Operators
|- piping pseudo-command : Talking to yourself
|| (OR) operator : C-style Logical (Short Circuit) Operators

debugger command : Debugger Commands

||= (assignment) operator : Assignment Operators

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

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