PERLUTIL

Section: Perl Programmers Reference Guide (1)
Updated: 2021-03-31
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NAME

perlutil - utilities packaged with the Perl distribution

DESCRIPTION

Along with the Perl interpreter itself, the Perl distribution installs a range of utilities on your system. There are also several utilities which are used by the Perl distribution itself as part of the install process. This document exists to list all of these utilities, explain what they are for and provide pointers to each module's documentation, if appropriate.

LIST OF UTILITIES

Documentation

perldoc: The main interface to Perl's documentation is "perldoc", although if you're reading this, it's more than likely that you've already found it. perldoc will extract and format the documentation from any file in the current directory, any Perl module installed on the system, or any of the standard documentation pages, such as this one. Use "perldoc <name>" to get information on any of the utilities described in this document.
pod2man and pod2text: If it's run from a terminal, perldoc will usually call pod2man to translate POD (Plain Old Documentation - see perlpod for an explanation) into a manpage, and then run man to display it; if man isn't available, pod2text will be used instead and the output piped through your favourite pager.
pod2html: As well as these two, there is another converter: pod2html will produce HTML pages from POD.
pod2usage: If you just want to know how to use the utilities described here, pod2usage will just extract the ``USAGE'' section; some of the utilities will automatically call pod2usage on themselves when you call them with "-help".
podchecker: If you're writing your own documentation in POD, the podchecker utility will look for errors in your markup.
splain: splain is an interface to perldiag - paste in your error message to it, and it'll explain it for you.
"roffitall": The "roffitall" utility is not installed on your system but lives in the pod/ directory of your Perl source kit; it converts all the documentation from the distribution to *roff format, and produces a typeset PostScript or text file of the whole lot.

Converters

To help you convert legacy programs to more modern Perl, the pl2pm utility will help you convert old-style Perl 4 libraries to new-style Perl5 modules.

Administration

libnetcfg: To display and change the libnet configuration run the libnetcfg command.
perlivp: The perlivp program is set up at Perl source code build time to test the Perl version it was built under. It can be used after running "make install" (or your platform's equivalent procedure) to verify that perl and its libraries have been installed correctly.

Development

There are a set of utilities which help you in developing Perl programs, and in particular, extending Perl with C.

perlbug: perlbug used to be the recommended way to report bugs in the perl interpreter itself or any of the standard library modules back to the developers; bug reports and patches should now be submitted to <https://github.com/Perl/perl5/issues>.
perlthanks: This program provides an easy way to send a thank-you message back to the authors and maintainers of perl. It's just perlbug installed under another name.
h2ph: Back before Perl had the XS system for connecting with C libraries, programmers used to get library constants by reading through the C header files. You may still see "require 'syscall.ph'" or similar around - the .ph file should be created by running h2ph on the corresponding .h file. See the h2ph documentation for more on how to convert a whole bunch of header files at once.
h2xs: h2xs converts C header files into XS modules, and will try and write as much glue between C libraries and Perl modules as it can. It's also very useful for creating skeletons of pure Perl modules.
enc2xs: enc2xs builds a Perl extension for use by Encode from either Unicode Character Mapping files (.ucm) or Tcl Encoding Files (.enc). Besides being used internally during the build process of the Encode module, you can use enc2xs to add your own encoding to perl. No knowledge of XS is necessary.
xsubpp: xsubpp is a compiler to convert Perl XS code into C code. It is typically run by the makefiles created by ExtUtils::MakeMaker.
xsubpp will compile XS code into C code by embedding the constructs necessary to let C functions manipulate Perl values and creates the glue necessary to let Perl access those functions.
prove: prove is a command-line interface to the test-running functionality of Test::Harness. It's an alternative to "make test".
corelist: A command-line front-end to "Module::CoreList", to query what modules were shipped with given versions of perl.

General tools

A few general-purpose tools are shipped with perl, mostly because they came along modules included in the perl distribution.

piconv: piconv is a Perl version of iconv, a character encoding converter widely available for various Unixen today. This script was primarily a technology demonstrator for Perl v5.8.0, but you can use piconv in the place of iconv for virtually any case.
ptar: ptar is a tar-like program, written in pure Perl.
ptardiff: ptardiff is a small utility that produces a diff between an extracted archive and an unextracted one. (Note that this utility requires the "Text::Diff" module to function properly; this module isn't distributed with perl, but is available from the CPAN.)
ptargrep: ptargrep is a utility to apply pattern matching to the contents of files in a tar archive.
shasum: This utility, that comes with the "Digest::SHA" module, is used to print or verify SHA checksums.
zipdetails: zipdetails displays information about the internal record structure of the zip file. It is not concerned with displaying any details of the compressed data stored in the zip file.

Installation

These utilities help manage extra Perl modules that don't come with the perl distribution.

cpan

cpan is a command-line interface to CPAN.pm. It allows you to install modules or distributions from CPAN, or just get information about them, and a lot more. It is similar to the command line mode of the CPAN module,

    perl -MCPAN -e shell

instmodsh

A little interface to ExtUtils::Installed to examine installed modules, validate your packlists and even create a tarball from an installed module.