1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.43)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings. \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
. ds -- \(*W-
. ds PI pi
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
. ds L" ""
. ds R" ""
. ds C` ""
. ds C' ""
'br\}
.el\{\
. ds -- \|\(em\|
. ds PI \(*p
. ds L" ``
. ds R" ''
. ds C`
. ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD. Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
. if \nF \{\
. de IX
. tm Index:\\$1\t\\n%\t"\\$2"
..
. if !\nF==2 \{\
. nr % 0
. nr F 2
. \}
. \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "PERLCHEAT 1"
.TH PERLCHEAT 1 "2023-11-25" "perl v5.36.0" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
perlcheat \- Perl 5 Cheat Sheet
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This 'cheat sheet' is a handy reference, meant for beginning Perl
programmers. Not everything is mentioned, but 195 features may
already be overwhelming.
.SS "The sheet"
.IX Subsection "The sheet"
.Vb 10
\& CONTEXTS SIGILS ref ARRAYS HASHES
\& void $scalar SCALAR @array %hash
\& scalar @array ARRAY @array[0, 2] @hash{\*(Aqa\*(Aq, \*(Aqb\*(Aq}
\& list %hash HASH $array[0] $hash{\*(Aqa\*(Aq}
\& &sub CODE
\& *glob GLOB SCALAR VALUES
\& FORMAT number, string, ref, glob, undef
\& REFERENCES
\& \e reference $$foo[1] aka $foo\->[1]
\& $@%&* dereference $$foo{bar} aka $foo\->{bar}
\& [] anon. arrayref ${$$foo[1]}[2] aka $foo\->[1]\->[2]
\& {} anon. hashref ${$$foo[1]}[2] aka $foo\->[1][2]
\& \e() list of refs
\& SYNTAX
\& OPERATOR PRECEDENCE foreach (LIST) { } for (a;b;c) { }
\& \-> while (e) { } until (e) { }
\& ++ \-\- if (e) { } elsif (e) { } else { }
\& ** unless (e) { } elsif (e) { } else { }
\& ! ~ \e u+ u\- given (e) { when (e) {} default {} }
\& =~ !~
\& * / % x NUMBERS vs STRINGS FALSE vs TRUE
\& + \- . = = undef, "", 0, "0"
\& << >> + . anything else
\& named uops == != eq ne
\& < > <= >= lt gt le ge < > <= >= lt gt le ge
\& == != <=> eq ne cmp ~~ <=> cmp
\& &
\& | ^ REGEX MODIFIERS REGEX METACHARS
\& && /i case insensitive ^ string begin
\& || // /m line based ^$ $ str end (bfr \en)
\& .. ... /s . includes \en + one or more
\& ?: /x /xx ign. wh.space * zero or more
\& = += last goto /p preserve ? zero or one
\& , => /a ASCII /aa safe {3,7} repeat in range
\& list ops /l locale /d dual | alternation
\& not /u Unicode [] character class
\& and /e evaluate /ee rpts \eb boundary
\& or xor /g global \ez string end
\& /o compile pat once () capture
\& DEBUG (?:p) no capture
\& \-MO=Deparse REGEX CHARCLASSES (?#t) comment
\& \-MO=Terse . [^\en] (?=p) ZW pos ahead
\& \-D## \es whitespace (?!p) ZW neg ahead
\& \-d:Trace \ew word chars (?<=p) ZW pos behind \eK
\& \ed digits (?<!p) ZW neg behind
\& CONFIGURATION \epP named property (?>p) no backtrack
\& perl \-V:ivsize \eh horiz.wh.space (?|p|p)branch reset
\& \eR linebreak (?<n>p)named capture
\& \eS \eW \eD \eH negate \eg{n} ref to named cap
\& \eK keep left part
\& 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 $\e 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 10 hinthash @INC include paths
\& 11 blksz 3..10 only @_ subroutine args
\& 12 blcks with EXPR %ENV environment
.Ve
.SH "ACKNOWLEDGEMENTS"
.IX Header "ACKNOWLEDGEMENTS"
The first version of this document appeared on Perl Monks, where several
people had useful suggestions. Thank you, Perl Monks.
.PP
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
Raku version to show that Perl will stay Perl.
.SH "AUTHOR"
.IX Header "AUTHOR"
Juerd Waalboer <#####@juerd.nl>, with the help of many Perl Monks.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
.IP "\(bu" 4
<https://perlmonks.org/?node_id=216602> \- the original \s-1PM\s0 post
.IP "\(bu" 4
<https://perlmonks.org/?node_id=238031> \- Damian Conway's Raku version
.IP "\(bu" 4
<https://juerd.nl/site.plp/perlcheat> \- home of the Perl Cheat Sheet
|
