Provided by: perl-doc_5.38.2-3.2ubuntu0.1_all 
NAME
perldoc - Look up Perl documentation in Pod format.
SYNOPSIS
perldoc [-h] [-D] [-t] [-u] [-m] [-l] [-U] [-F]
[-i] [-V] [-T] [-r]
[-d destination_file]
[-o formatname]
[-M FormatterClassName]
[-w formatteroption:value]
[-n nroff-replacement]
[-X]
[-L language_code]
PageName|ModuleName|ProgramName|URL
Examples:
perldoc -f BuiltinFunction
perldoc -L it -f BuiltinFunction
perldoc -q FAQ Keyword
perldoc -L fr -q FAQ Keyword
perldoc -v PerlVariable
perldoc -a PerlAPI
See below for more description of the switches.
DESCRIPTION
perldoc looks up documentation in .pod format that is embedded in the perl installation tree or in a perl
script, and displays it using a variety of formatters. This is primarily used for the documentation for
the perl library modules.
Your system may also have man pages installed for those modules, in which case you can probably just use
the man(1) command.
If you are looking for a table of contents to the Perl library modules documentation, see the perltoc
page.
OPTIONS
-h Prints out a brief help message.
-D Describes search for the item in detail.
-t Display docs using plain text converter, instead of nroff. This may be faster, but it probably won't
look as nice.
-u Skip the real Pod formatting, and just show the raw Pod source (Unformatted)
-m module
Display the entire module: both code and unformatted pod documentation. This may be useful if the
docs don't explain a function in the detail you need, and you'd like to inspect the code directly;
perldoc will find the file for you and simply hand it off for display.
-l Display only the file name of the module found.
-U When running as the superuser, don't attempt drop privileges for security. This option is implied
with -F.
NOTE: Please see the heading SECURITY below for more information.
-F Consider arguments as file names; no search in directories will be performed. Implies -U if run as
the superuser.
-f perlfunc
The -f option followed by the name of a perl built-in function will extract the documentation of
this function from perlfunc.
Example:
perldoc -f sprintf
-q perlfaq-search-regexp
The -q option takes a regular expression as an argument. It will search the question headings in
perlfaq[1-9] and print the entries matching the regular expression.
Example:
perldoc -q shuffle
-a perlapifunc
The -a option followed by the name of a perl api function will extract the documentation of this
function from perlapi.
Example:
perldoc -a newHV
-v perlvar
The -v option followed by the name of a Perl predefined variable will extract the documentation of
this variable from perlvar.
Examples:
perldoc -v '$"'
perldoc -v @+
perldoc -v DATA
-T This specifies that the output is not to be sent to a pager, but is to be sent directly to STDOUT.
-d destination-filename
This specifies that the output is to be sent neither to a pager nor to STDOUT, but is to be saved to
the specified filename. Example: "perldoc -oLaTeX -dtextwrapdocs.tex Text::Wrap"
-o output-formatname
This specifies that you want Perldoc to try using a Pod-formatting class for the output format that
you specify. For example: "-oman". This is actually just a wrapper around the "-M" switch; using
"-oformatname" just looks for a loadable class by adding that format name (with different
capitalizations) to the end of different classname prefixes.
For example, "-oLaTeX" currently tries all of the following classes: Pod::Perldoc::ToLaTeX
Pod::Perldoc::Tolatex Pod::Perldoc::ToLatex Pod::Perldoc::ToLATEX Pod::Simple::LaTeX
Pod::Simple::latex Pod::Simple::Latex Pod::Simple::LATEX Pod::LaTeX Pod::latex Pod::Latex
Pod::LATEX.
-M module-name
This specifies the module that you want to try using for formatting the pod. The class must at
least provide a "parse_from_file" method. For example: "perldoc -MPod::Perldoc::ToChecker".
You can specify several classes to try by joining them with commas or semicolons, as in
"-MTk::SuperPod;Tk::Pod".
-w option:value or -w option
This specifies an option to call the formatter with. For example, "-w textsize:15" will call
"$formatter->textsize(15)" on the formatter object before it is used to format the object. For this
to be valid, the formatter class must provide such a method, and the value you pass should be valid.
(So if "textsize" expects an integer, and you do "-w textsize:big", expect trouble.)
You can use "-w optionname" (without a value) as shorthand for "-w optionname:TRUE". This is
presumably useful in cases of on/off features like: "-w page_numbering".
You can use an "=" instead of the ":", as in: "-w textsize=15". This might be more (or less)
convenient, depending on what shell you use.
-X Use an index if it is present. The -X option looks for an entry whose basename matches the name
given on the command line in the file "$Config{archlib}/pod.idx". The pod.idx file should contain
fully qualified filenames, one per line.
-L language_code
This allows one to specify the language code for the desired language translation. If the
"POD2::<language_code>" package isn't installed in your system, the switch is ignored. All
available translation packages are to be found under the "POD2::" namespace. See POD2::IT (or
POD2::FR) to see how to create new localized "POD2::*" documentation packages and integrate them
into Pod::Perldoc.
PageName|ModuleName|ProgramName|URL
The item you want to look up. Nested modules (such as "File::Basename") are specified either as
"File::Basename" or "File/Basename". You may also give a descriptive name of a page, such as
"perlfunc". For URLs, HTTP and HTTPS are the only kind currently supported.
For simple names like 'foo', when the normal search fails to find a matching page, a search with the
"perl" prefix is tried as well. So "perldoc intro" is enough to find/render "perlintro.pod".
-n some-formatter
Specify replacement for groff
-r Recursive search.
-i Ignore case.
-V Displays the version of perldoc you're running.
SECURITY
Because perldoc does not run properly tainted, and is known to have security issues, when run as the
superuser it will attempt to drop privileges by setting the effective and real IDs to nobody's or
nouser's account, or -2 if unavailable. If it cannot relinquish its privileges, it will not run.
See the "-U" option if you do not want this behavior but beware that there are significant security risks
if you choose to use "-U".
Since 3.26, using "-F" as the superuser also implies "-U" as opening most files and traversing
directories requires privileges that are above the nobody/nogroup level.
ENVIRONMENT
Any switches in the "PERLDOC" environment variable will be used before the command line arguments.
Useful values for "PERLDOC" include "-oterm", "-otext", "-ortf", "-oxml", and so on, depending on what
modules you have on hand; or the formatter class may be specified exactly with "-MPod::Perldoc::ToTerm"
or the like.
"perldoc" also searches directories specified by the "PERL5LIB" (or "PERLLIB" if "PERL5LIB" is not
defined) and "PATH" environment variables. (The latter is so that embedded pods for executables, such as
"perldoc" itself, are available.)
In directories where either "Makefile.PL" or "Build.PL" exist, "perldoc" will add "." and "lib" first to
its search path, and as long as you're not the superuser will add "blib" too. This is really helpful if
you're working inside of a build directory and want to read through the docs even if you have a version
of a module previously installed.
"perldoc" will use, in order of preference, the pager defined in "PERLDOC_PAGER", "MANPAGER", or "PAGER"
before trying to find a pager on its own. ("MANPAGER" is not used if "perldoc" was told to display plain
text or unformatted pod.)
When using perldoc in it's "-m" mode (display module source code), "perldoc" will attempt to use the
pager set in "PERLDOC_SRC_PAGER". A useful setting for this command is your favorite editor as in
"/usr/bin/nano". (Don't judge me.)
One useful value for "PERLDOC_PAGER" is "less -+C -E".
Having PERLDOCDEBUG set to a positive integer will make perldoc emit even more descriptive output than
the "-D" switch does; the higher the number, the more it emits.
CHANGES
Up to 3.14_05, the switch -v was used to produce verbose messages of perldoc operation, which is now
enabled by -D.
SEE ALSO
perlpod, Pod::Perldoc
AUTHOR
Current maintainer: Mark Allen "<mallen@cpan.org>"
Past contributors are: brian d foy "<bdfoy@cpan.org>" Adriano R. Ferreira "<ferreira@cpan.org>", Sean M.
Burke "<sburke@cpan.org>", Kenneth Albanowski "<kjahds@kjahds.com>", Andy Dougherty
"<doughera@lafcol.lafayette.edu>", and many others.
perl v5.38.2 2025-04-08 PERLDOC(1)