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 and pod2latex

As well as these two, there are two other converters: pod2html will produce HTML pages from POD, and pod2latex, which produces LaTeX files.

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".

podselect

pod2usage is a special case of podselect, a utility to extract named sections from documents written in POD. For instance, while utilities have "USAGE" sections, Perl modules usually have "SYNOPSIS" sections: "podselect -s "SYNOPSIS" ..." will extract this section for a given file.

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 Perl, we've included three conversion filters:

a2p

a2p converts awk scripts to Perl programs; for example, "a2p -F:" on the simple awk script "{print $2}" will produce a Perl program based around this code:

    while (<>) {
        ($Fld1,$Fld2) = split(/[:\n]/, $_, -1);
        print $Fld2;
    }
    

s2p and psed

Similarly, s2p converts sed scripts to Perl programs. s2p run on "s/foo/bar" will produce a Perl program based around this:

    while (<>) {
        chomp;
        s/foo/bar/g;
        print if $printit;
    }
    

When invoked as psed, it behaves as a sed implementation, written in Perl.

find2perl

Finally, find2perl translates "find" commands to Perl equivalents which use the File::Find module. As an example, "find2perl . -user root -perm 4000 -print" produces the following callback subroutine for "File::Find":

    sub wanted {
        my ($dev,$ino,$mode,$nlink,$uid,$gid);
        (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) &&
        $uid == $uid{'root'}) &&
        (($mode & 0777) == 04000);
        print("$name\n");
    }
    

As well as these filters for converting other languages, the pl2pm utility will help you convert old-style Perl 4 libraries to new-style Perl5 modules.

Administration¶

config_data

Query or change configuration of Perl modules that use Module::Build-based configuration files for features and config data.

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 is the recommended way to report bugs in the perl interpreter itself or any of the standard library modules back to the developers; please read through the documentation for perlbug thoroughly before using it to submit a bug report.

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.

c2ph and pstruct

c2ph and pstruct, which are actually the same program but behave differently depending on how they are called, provide another way of getting at C with Perl - they'll convert C structures and union declarations to Perl code. This is deprecated in favour of h2xs these days.

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 5.8.0, 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
    

cpanp

cpanp is, like cpan, a command-line interface to the CPAN, using the "CPANPLUS" module as a back-end. It can be used interactively or imperatively.

cpan2dist

cpan2dist is a tool to create distributions (or packages) from CPAN modules, then suitable for your package manager of choice. Support for specific formats are available from CPAN as "CPANPLUS::Dist::*" modules.

instmodsh

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