Perl Cookbook, Second Edition
| [SYMBOL] [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] " (double quote) escaping # (pound sign), with printf( ) $ (dollar sign) $! variable $#ARRAY variable $$ variable 2nd 3rd $& variable 2nd $* variable (deprecated) $+ variable $. variable 2nd $/ variable $; variable $? variable 2nd 3rd 4th $@ variable 2nd $^F variable $^I variable $^O variable 2nd $^W variable $_ variable 2nd 3rd accidental clobbering outlawing unauthorized use $` variable $| variable 2nd $0 variable 2nd $1, $2, . . . (backreferences) 2nd finding doubled words $VERSION variable (use pragma) hashes % (percent sign) %SIG hash hashes & (ampersand), && operator > (right angle bracket), file-access modes 2nd < (left angle bracket) <&= and <& open modes <=> numerical comparison operator <FH> line input operator file-access modes 2nd <> (angle brackets) globbing line input operator reading strings from binary files ' (single quote) escaping ( ) (parentheses) autouse pragma prototyping functions substitution * (asterisk), typeglobs + (plus sign), file-access modes , (comma) in numbers printing lists with - (hyphen) -> (arrow) operator 2nd -> (infix) notation -0 command-line option -a command-line option, writing filters -e command-line option, writing filters -i command-line option modifying files with writing filters -I command-line switch -n command-line option, writing filters -p command-line option modifying files with writing filters -t command-line option - (minus sign), modifiers and -C command-line switch . (dot) . . and . . . range operators period in numbers / (forward slash) /e substitution modifier 2nd /g pattern-matching modifier finding Nth matches where last pattern ended /i pattern-matching modifier /m pattern-matching modifier multiple lines /o pattern-matching modifier /s pattern-matching modifier multiple lines /x pattern modifier comments in regular expressions root directory : (colon) module names package names = (equals sign) => operator =~ operator =begin pod directive =end pod directive @ (at sign) @_ array @EXPORT array (use pragma) @EXPORT_OK array (use pragma) @EXPORT_TAGS array (use pragma) @INC array references to arrays splice( ) [] (square brackets) creating anonymous arrays and hashes \ (backslash) \1, \2, . . . (backreferences) \a for terminal bell \E string metacharacter \G anchor \L string escape \l string escape \U string escape \u string escape \X metacharacter ` string metacharacter creating arrays creating references escaping characters references to arrays references to scalars _ (underscore), file stat cache ` (backtick) executing commands without shell escapes expanding gathering program output running another program {} (curly braces) creating anonymous arrays and hashes | (vertical bar) || operator vs. or operator separating multiple comparisons ||= (assignment) operator ~ (tilde), in filenames, expanding -0 command-line option $0 variable |