1perldoc(3) User Contributed Perl Documentation perldoc(3)
2
6 perldoc - Look up Perl documentation in Pod format.
7
9 perldoc [-h] [-D] [-t] [-u] [-m] [-l] [-U] [-F]
10 [-i] [-V] [-T] [-r]
11 [-d destination_file]
12 [-o formatname]
13 [-M FormatterClassName]
14 [-w formatteroption:value]
15 [-n nroff-replacement]
16 [-X]
17 [-L language_code]
18 PageName|ModuleName|ProgramName|URL
19 Examples:
21 perldoc -f BuiltinFunction
23 perldoc -L it -f BuiltinFunction
25 perldoc -q FAQ Keyword
27 perldoc -L fr -q FAQ Keyword
29 perldoc -v PerlVariable
31 perldoc -a PerlAPI
33 See below for more description of the switches.
35
37 perldoc looks up documentation in .pod format that is embedded in the
38 perl installation tree or in a perl script, and displays it using a
39 variety of formatters. This is primarily used for the documentation
40 for the perl library modules.
41 Your system may also have man pages installed for those modules, in
43 which case you can probably just use the man(1) command.
44 If you are looking for a table of contents to the Perl library modules
46 documentation, see the perltoc page.
47
49 -h Prints out a brief help message.
50 -D Describes search for the item in detail.
52 -t Display docs using plain text converter, instead of nroff. This
54 may be faster, but it probably won't look as nice.
55 -u Skip the real Pod formatting, and just show the raw Pod source
57 (Unformatted)
58 -m module
60 Display the entire module: both code and unformatted pod
61 documentation. This may be useful if the docs don't explain a
62 function in the detail you need, and you'd like to inspect the
63 code directly; perldoc will find the file for you and simply hand
64 it off for display.
65 -l Display only the file name of the module found.
67 -U When running as the superuser, don't attempt drop privileges for
69 security. This option is implied with -F.
70 NOTE: Please see the heading SECURITY below for more information.
72 -F Consider arguments as file names; no search in directories will be
74 performed. Implies -U if run as the superuser.
75 -f perlfunc
77 The -f option followed by the name of a perl built-in function
78 will extract the documentation of this function from perlfunc.
79 Example:
81 perldoc -f sprintf
83 -q perlfaq-search-regexp
85 The -q option takes a regular expression as an argument. It will
86 search the question headings in perlfaq[1-9] and print the entries
87 matching the regular expression.
88 Example:
90 perldoc -q shuffle
92 -a perlapifunc
94 The -a option followed by the name of a perl api function will
95 extract the documentation of this function from perlapi.
96 Example:
98 perldoc -a newHV
100 -v perlvar
102 The -v option followed by the name of a Perl predefined variable
103 will extract the documentation of this variable from perlvar.
104 Examples:
106 perldoc -v '$"'
108 perldoc -v @+
109 perldoc -v DATA
110 -T This specifies that the output is not to be sent to a pager, but
112 is to be sent directly to STDOUT.
113 -d destination-filename
115 This specifies that the output is to be sent neither to a pager
116 nor to STDOUT, but is to be saved to the specified filename.
117 Example: "perldoc -oLaTeX -dtextwrapdocs.tex Text::Wrap"
118 -o output-formatname
120 This specifies that you want Perldoc to try using a Pod-formatting
121 class for the output format that you specify. For example:
122 "-oman". This is actually just a wrapper around the "-M" switch;
123 using "-oformatname" just looks for a loadable class by adding
124 that format name (with different capitalizations) to the end of
125 different classname prefixes.
126 For example, "-oLaTeX" currently tries all of the following
128 classes: Pod::Perldoc::ToLaTeX Pod::Perldoc::Tolatex
129 Pod::Perldoc::ToLatex Pod::Perldoc::ToLATEX Pod::Simple::LaTeX
130 Pod::Simple::latex Pod::Simple::Latex Pod::Simple::LATEX
131 Pod::LaTeX Pod::latex Pod::Latex Pod::LATEX.
132 -M module-name
134 This specifies the module that you want to try using for
135 formatting the pod. The class must at least provide a
136 "parse_from_file" method. For example: "perldoc
137 -MPod::Perldoc::ToChecker".
138 You can specify several classes to try by joining them with commas
140 or semicolons, as in "-MTk::SuperPod;Tk::Pod".
141 -w option:value or -w option
143 This specifies an option to call the formatter with. For example,
144 "-w textsize:15" will call "$formatter->textsize(15)" on the
145 formatter object before it is used to format the object. For this
146 to be valid, the formatter class must provide such a method, and
147 the value you pass should be valid. (So if "textsize" expects an
148 integer, and you do "-w textsize:big", expect trouble.)
149 You can use "-w optionname" (without a value) as shorthand for "-w
151 optionname:TRUE". This is presumably useful in cases of on/off
152 features like: "-w page_numbering".
153 You can use an "=" instead of the ":", as in: "-w textsize=15".
155 This might be more (or less) convenient, depending on what shell
156 you use.
157 -X Use an index if it is present. The -X option looks for an entry
159 whose basename matches the name given on the command line in the
160 file "$Config{archlib}/pod.idx". The pod.idx file should contain
161 fully qualified filenames, one per line.
162 -L language_code
164 This allows one to specify the language code for the desired
165 language translation. If the "POD2::<language_code>" package isn't
166 installed in your system, the switch is ignored. All available
167 translation packages are to be found under the "POD2::" namespace.
168 See POD2::IT (or POD2::FR) to see how to create new localized
169 "POD2::*" documentation packages and integrate them into
170 Pod::Perldoc.
171 PageName|ModuleName|ProgramName|URL
173 The item you want to look up. Nested modules (such as
174 "File::Basename") are specified either as "File::Basename" or
175 "File/Basename". You may also give a descriptive name of a page,
176 such as "perlfunc". For URLs, HTTP and HTTPS are the only kind
177 currently supported.
178 For simple names like 'foo', when the normal search fails to find
180 a matching page, a search with the "perl" prefix is tried as well.
181 So "perldoc intro" is enough to find/render "perlintro.pod".
182 -n some-formatter
184 Specify replacement for groff
185 -r Recursive search.
187 -i Ignore case.
189 -V Displays the version of perldoc you're running.
191
193 Because perldoc does not run properly tainted, and is known to have
194 security issues, when run as the superuser it will attempt to drop
195 privileges by setting the effective and real IDs to nobody's or
196 nouser's account, or -2 if unavailable. If it cannot relinquish its
197 privileges, it will not run.
198 See the "-U" option if you do not want this behavior but beware that
200 there are significant security risks if you choose to use "-U".
201 Since 3.26, using "-F" as the superuser also implies "-U" as opening
203 most files and traversing directories requires privileges that are
204 above the nobody/nogroup level.
205
207 Any switches in the "PERLDOC" environment variable will be used before
208 the command line arguments.
209 Useful values for "PERLDOC" include "-oterm", "-otext", "-ortf",
211 "-oxml", and so on, depending on what modules you have on hand; or the
212 formatter class may be specified exactly with "-MPod::Perldoc::ToTerm"
213 or the like.
214 "perldoc" also searches directories specified by the "PERL5LIB" (or
216 "PERLLIB" if "PERL5LIB" is not defined) and "PATH" environment
217 variables. (The latter is so that embedded pods for executables, such
218 as "perldoc" itself, are available.)
219 In directories where either "Makefile.PL" or "Build.PL" exist,
221 "perldoc" will add "." and "lib" first to its search path, and as long
222 as you're not the superuser will add "blib" too. This is really
223 helpful if you're working inside of a build directory and want to read
224 through the docs even if you have a version of a module previously
225 installed.
226 "perldoc" will use, in order of preference, the pager defined in
228 "PERLDOC_PAGER", "MANPAGER", or "PAGER" before trying to find a pager
229 on its own. ("MANPAGER" is not used if "perldoc" was told to display
230 plain text or unformatted pod.)
231 When using perldoc in it's "-m" mode (display module source code),
233 "perldoc" will attempt to use the pager set in "PERLDOC_SRC_PAGER". A
234 useful setting for this command is your favorite editor as in
235 "/usr/bin/nano". (Don't judge me.)
236 One useful value for "PERLDOC_PAGER" is "less -+C -E".
238 Having PERLDOCDEBUG set to a positive integer will make perldoc emit
240 even more descriptive output than the "-D" switch does; the higher the
241 number, the more it emits.
242
244 Up to 3.14_05, the switch -v was used to produce verbose messages of
245 perldoc operation, which is now enabled by -D.
246
248 perlpod, Pod::Perldoc
249
251 Current maintainer: Mark Allen "<mallen@cpan.org>"
252 Past contributors are: brian d foy "<bdfoy@cpan.org>" Adriano R.
254 Ferreira "<ferreira@cpan.org>", Sean M. Burke "<sburke@cpan.org>",
255 Kenneth Albanowski "<kjahds@kjahds.com>", Andy Dougherty
256 "<doughera@lafcol.lafayette.edu>", and many others.
257perl v5.30.1 2020-01-30 perldoc(3)