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perlcheat(1) [x11r4 man page]

PERLCHEAT(1)						 Perl Programmers Reference Guide					      PERLCHEAT(1)

NAME
perlcheat - Perl 5 Cheat Sheet DESCRIPTION
This 'cheat sheet' is a handy reference, meant for beginning Perl programmers. Not everything is mentioned, but 195 features may already be overwhelming. The sheet CONTEXTS SIGILS ARRAYS HASHES void $scalar whole: @array %hash scalar @array slice: @array[0, 2] @hash{'a', 'b'} list %hash element: $array[0] $hash{'a'} &sub *glob SCALAR VALUES number, string, reference, glob, undef REFERENCES references $$foo[1] aka $foo->[1] $@%&* dereference $$foo{bar} aka $foo->{bar} [] anon. arrayref ${$$foo[1]}[2] aka $foo->[1]->[2] {} anon. hashref ${$$foo[1]}[2] aka $foo->[1][2] () list of refs NUMBERS vs STRINGS LINKS OPERATOR PRECEDENCE = = perl.plover.com -> + . search.cpan.org ++ -- == != eq ne cpan.org ** < > <= >= lt gt le ge pm.org ! ~ u+ u- <=> cmp tpj.com =~ !~ perldoc.com * / % x SYNTAX + - . for (LIST) { }, for (a;b;c) { } << >> while ( ) { }, until ( ) { } named uops if ( ) { } elsif ( ) { } else { } < > <= >= lt gt le ge unless ( ) { } elsif ( ) { } else { } == != <=> eq ne cmp for equals foreach (ALWAYS) & | ^ REGEX METACHARS REGEX MODIFIERS && ^ string begin /i case insens. || $ str. end (before ) /m line based ^$ .. ... + one or more /s . includes ?: * zero or more /x ign. wh.space = += -= *= etc. ? zero or one /g global , => {3,7} repeat in range /o cmpl pat. once list ops () capture not (?:) no capture REGEX CHARCLASSES and [] character class . == [^ ] or xor | alternation s == whitespace  word boundary w == word characters z string end d == digits DO S, W and D negate use strict; DON'T use warnings; "$foo" LINKS my $var; $$variable_name perl.com open() or die $!; `$userinput` use.perl.org use Modules; /$userinput/ perl.apache.org FUNCTION RETURN LISTS stat localtime caller SPECIAL VARIABLES 0 dev 0 second 0 package $_ default variable 1 ino 1 minute 1 filename $0 program name 2 mode 2 hour 2 line $/ input separator 3 nlink 3 day 3 subroutine $ output separator 4 uid 4 month-1 4 hasargs $| autoflush 5 gid 5 year-1900 5 wantarray $! sys/libcall error 6 rdev 6 weekday 6 evaltext $@ eval error 7 size 7 yearday 7 is_require $$ process ID 8 atime 8 is_dst 8 hints $. line number 9 mtime 9 bitmask @ARGV command line args 10 ctime just use @INC include paths 11 blksz POSIX:: 3..9 only @_ subroutine args 12 blcks strftime! with EXPR %ENV environment ACKNOWLEDGEMENTS
The first version of this document appeared on Perl Monks, where several people had useful suggestions. Thank you, Perl Monks. A special thanks to Damian Conway, who didn't only suggest important changes, but also took the time to count the number of listed features and make a Perl 6 version to show that Perl will stay Perl. AUTHOR
Juerd Waalboer <#####@juerd.nl>, with the help of many Perl Monks. SEE ALSO
http://perlmonks.org/?node_id=216602 the original PM post http://perlmonks.org/?node_id=238031 Damian Conway's Perl 6 version http://juerd.nl/site.plp/perlcheat home of the Perl Cheat Sheet perl v5.8.9 2007-11-17 PERLCHEAT(1)

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Devel::Backtrace::Point(3pm)				User Contributed Perl Documentation			      Devel::Backtrace::Point(3pm)

NAME
Devel::Backtrace::Point - Object oriented access to the information caller() provides SYNOPSIS
print Devel::Backtrace::Point->new([caller(0)])->to_long_string; DESCRIPTION
This class is a nice way to access all the information caller provides on a given level. It is used by Devel::Backtrace, which generates an array of all trace points. METHODS
$p->package, $p->filename, $p->line, $p->subroutine, $p->hasargs, $p->wantarray, $p->evaltext, $p->is_require, $p->hints, $p->bitmask, $p->hinthash See "caller" in perlfunc for documentation of these fields. hinthash is only available in perl 5.9 and higher. When this module is loaded, it tests how many values caller returns. Depending on the result, it adds the necessary accessors. Thus, you should be able to find out if your perl supports hinthash by using "can" in UNIVERSAL: Devel::Backtrace::Point->can('hinthash'); $p->level This is the level given to new(). It's intended to be the parameter that was given to caller(). $p->called_package This returns the package that $p->subroutine is in. If $p->subroutine does not contain '::', then '(unknown)' is returned. This is the case if $p->subroutine is '(eval)'. $p->by_index($i) You may also access the fields by their index in the list that caller() returns. This may be useful if some future perl version introduces a new field for caller, and the author of this module doesn't react in time. new([caller($i)]) This constructs a Devel::Backtrace object. The argument must be a reference to an array holding the return values of caller(). This array must have either three or ten elements (or eleven if hinthash is supported) (see "caller" in perlfunc). Optional additional parameters: -format => 'formatstring', -level => $i The format string will be used as a default for to_string(). The level should be the parameter that was given to caller() to obtain the caller information. $tracepoint->to_string() Returns a string of the form "Blah::subname called from main (foo.pl:17)". This means that the subroutine "subname" from package "Blah" was called by package "main" in "foo.pl" line 17. If you print a "Devel::Backtrace::Point" object or otherwise treat it as a string, to_string() will be called automatically due to overloading. Optional parameters: -format => 'formatstring' The format string changes the appearance of the return value. It can contain %p (package), %c (called_package), %f (filename), %l (line), %s (subroutine), %a (hasargs), %e (evaltext), %r (is_require), %h (hints), %b (bitmask), %i (level), %I (level, see below). The difference between %i and %I is that the former is the argument to caller() while the latter is actually the index in $backtrace->points(). %i and %I are different if "-start", skipme() or skipmysubs() is used in Devel::Backtrace. If no format string is given, the one passed to "new" will be used. If none was given to "new", the format string defaults to 'default', which is an abbreviation for "%s called from %p (%f:%l)". Format strings have been added in Devel-Backtrace-0.10. $tracepoint->to_long_string() This returns a string which lists all available fields in a table that spans several lines. Example: package: main filename: /tmp/foo.pl line: 6 subroutine: main::foo hasargs: 1 wantarray: undef evaltext: undef is_require: undef hints: 0 bitmask: 000000000000 hinthash is not included in the output, as it is a hash. FIELDS This constant contains a list of all the available field names. The number of fields depends on your perl version. SEE ALSO
Devel::Backtrace AUTHOR
Christoph Bussenius <pepe@cpan.org> LICENSE
This Perl module is in the public domain. If your country's law does not allow this module being in the public domain or does not include the concept of public domain, you may use the module under the same terms as perl itself. perl v5.10.0 2009-01-27 Devel::Backtrace::Point(3pm)
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