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NAME

ppisel - Select PPI::Element nodes using CSel syntax

VERSION

This document describes version 0.001 of ppisel (from Perl distribution App-ppisel), released on 2019-07-29.

SYNOPSIS

To print all 'print' statements:

 % ppisel script.pl '.Statement:has(.Token::Word[content="print"])'

To print the first comment:

 % ppisel script.pl 'Comment:first'

To dump PPI document tree (--root select the root node, --dump dumps the content):

 % ppisel script.pl --root --dump

DESCRIPTION

This utility uses CSel to select against a tree of PPI::Element nodes, constructed by PPI from a Perl source code.

About the tree: the root node is PPI::Document object, which is a subclass of PPI::Element. The other nodes are also subclasses of PPI::Element. This utility allows you to omit the PPI::Token:: or PPI:: prefix, so to select a word token can use:

 .Token::Word

or just:

 .Word

OPTIONS

* marks required options.

Main options

--count

Shortcut for --node-action count.

See --node-action.

--dump

Shortcut for --node-action dump.

See --node-action.

--expr=s
--file=filename

Default value:

 "-"
--node-action=s@

Specify action(s) to perform on matching nodes.

Default value:

 ["print_as_string"]

Each action can be one of the following:

* `count` will print the number of matching nodes.

* `print_method` will call on or more of the node object's methods and print the result. Example:

    print_method:as_string

* `dump` will show a indented text representation of the node and its descendants. Each line will print information about a single node: its class, followed by the value of one or more attributes. You can specify which attributes to use in a dot-separated syntax, e.g.:

    dump:tag.id.class

which will result in a node printed like this:

    HTML::Element tag=p id=undef class=undef

By default, if no attributes are specified, `id` is used. If the node class does not support the attribute, or if the value of the attribute is undef, then `undef` is shown.

Can be specified multiple times.

--node-actions-json=s

Specify action(s) to perform on matching nodes (JSON-encoded).

See --node-action.

--print

Shortcut for --node-action print_as_string.

See --node-action.

--print-method=s@

--print-method M is shortcut for --node-action print_method:M.

See --node-action.

Can be specified multiple times.

--root

Shortcut for --select-action=root.

See --select-action.

--select-action=s

Specify how we should select nodes.

Default value:

 "csel"

Valid values:

 ["csel","root"]

The default is `csel`, which will select nodes from the tree using the CSel expression. Note that the root node itself is not included. For more details on CSel expression, refer to <pm:Data::CSel>.

`root` will return a single node which is the root node.

Configuration options

--config-path=s, -c

Set path to configuration file.

--config-profile=s, -P

Set configuration profile to use.

--no-config, -C

Do not use any configuration file.

Environment options

--no-env

Do not read environment for default options.

Output options

--format=s

Choose output format, e.g. json, text.

Default value:

 undef
--json

Set output format to json.

--naked-res

When outputing as JSON, strip result envelope.

Default value:

 0

By default, when outputing as JSON, the full enveloped result is returned, e.g.:

    [200,"OK",[1,2,3],{"func.extra"=>4}]

The reason is so you can get the status (1st element), status message (2nd element) as well as result metadata/extra result (4th element) instead of just the result (3rd element). However, sometimes you want just the result, e.g. when you want to pipe the result for more post-processing. In this case you can use `--naked-res` so you just get:

    [1,2,3]

Other options

--help, -h, -?

Display help message and exit.

--version, -v

Display program's version and exit.

COMPLETION

This script has shell tab completion capability with support for several shells.

bash

To activate bash completion for this script, put:

 complete -C ppisel ppisel

in your bash startup (e.g. ~/.bashrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.

It is recommended, however, that you install modules using cpanm-shcompgen which can activate shell completion for scripts immediately.

tcsh

To activate tcsh completion for this script, put:

 complete ppisel 'p/*/`ppisel`/'

in your tcsh startup (e.g. ~/.tcshrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.

It is also recommended to install shcompgen (see above).

other shells

For fish and zsh, install shcompgen as described above.

CONFIGURATION FILE

This script can read configuration files. Configuration files are in the format of IOD, which is basically INI with some extra features.

By default, these names are searched for configuration filenames (can be changed using --config-path): ~/.config/ppisel.conf, ~/ppisel.conf, or /etc/ppisel.conf.

All found files will be read and merged.

To disable searching for configuration files, pass --no-config.

You can put multiple profiles in a single file by using section names like [profile=SOMENAME] or [SOMESECTION profile=SOMENAME]. Those sections will only be read if you specify the matching --config-profile SOMENAME.

You can also put configuration for multiple programs inside a single file, and use filter program=NAME in section names, e.g. [program=NAME ...] or [SOMESECTION program=NAME]. The section will then only be used when the reading program matches.

Finally, you can filter a section by environment variable using the filter env=CONDITION in section names. For example if you only want a section to be read if a certain environment variable is true: [env=SOMEVAR ...] or [SOMESECTION env=SOMEVAR ...]. If you only want a section to be read when the value of an environment variable has value equals something: [env=HOSTNAME=blink ...] or [SOMESECTION env=HOSTNAME=blink ...]. If you only want a section to be read when the value of an environment variable does not equal something: [env=HOSTNAME!=blink ...] or [SOMESECTION env=HOSTNAME!=blink ...]. If you only want a section to be read when an environment variable contains something: [env=HOSTNAME*=server ...] or [SOMESECTION env=HOSTNAME*=server ...]. Note that currently due to simplistic parsing, there must not be any whitespace in the value being compared because it marks the beginning of a new section filter or section name.

List of available configuration parameters:

 expr (see --expr)
 file (see --file)
 format (see --format)
 naked_res (see --naked-res)
 node_actions (see --node-action)
 select_action (see --select-action)

ENVIRONMENT

PPISEL_OPT => str

Specify additional command-line options.

FILES

~/.config/ppisel.conf

~/ppisel.conf

/etc/ppisel.conf

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/App-ppisel.

SOURCE

Source repository is at https://github.com/perlancar/perl-App-ppisel.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=App-ppisel

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

SEE ALSO

Data::CSel

PPI

Other utilities that use CSel against various data: ddsel, jsonsel, orgsel, podsel, htmlsel, yamlsel.

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2019 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.