***

## Registration

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-add-hook/">WP_CLI::add_hook()</a></strong> - Schedule a callback to be executed at a certain point.</li>


<li><strong><a href="/docs/internal-api/wp-cli-do-hook/">WP_CLI::do_hook()</a></strong> - Execute callbacks registered to a given hook.</li>


<li><strong><a href="/docs/internal-api/wp-cli-add-wp-hook/">WP_CLI::add_wp_hook()</a></strong> - Add a callback to a WordPress action or filter.</li>


<li><strong><a href="/docs/internal-api/wp-cli-add-command/">WP_CLI::add_command()</a></strong> - Register a command to WP-CLI.</li>


</ul>


## Output

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-utils-format-items/">WP_CLI\Utils\format_items()</a></strong> - Render a collection of items as an ASCII table, JSON, CSV, YAML, list of ids, or count.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-make-progress-bar/">WP_CLI\Utils\make_progress_bar()</a></strong> - Create a progress bar to display percent completion of a given operation.</li>


<li><strong><a href="/docs/internal-api/wp-cli-colorize/">WP_CLI::colorize()</a></strong> - Colorize a string for output.</li>


<li><strong><a href="/docs/internal-api/wp-cli-line/">WP_CLI::line()</a></strong> - Display informational message without prefix, and ignore `--quiet`.</li>


<li><strong><a href="/docs/internal-api/wp-cli-log/">WP_CLI::log()</a></strong> - Display informational message without prefix.</li>


<li><strong><a href="/docs/internal-api/wp-cli-success/">WP_CLI::success()</a></strong> - Display success message prefixed with &quot;Success: &quot;.</li>


<li><strong><a href="/docs/internal-api/wp-cli-debug/">WP_CLI::debug()</a></strong> - Display debug message prefixed with &quot;Debug: &quot; when `--debug` is used.</li>


<li><strong><a href="/docs/internal-api/wp-cli-warning/">WP_CLI::warning()</a></strong> - Display warning message prefixed with &quot;Warning: &quot;.</li>


<li><strong><a href="/docs/internal-api/wp-cli-error/">WP_CLI::error()</a></strong> - Display error message prefixed with &quot;Error: &quot; and exit script.</li>


<li><strong><a href="/docs/internal-api/wp-cli-halt/">WP_CLI::halt()</a></strong> - Halt script execution with a specific return code.</li>


<li><strong><a href="/docs/internal-api/wp-cli-error-multi-line/">WP_CLI::error_multi_line()</a></strong> - Display a multi-line error message in a red box. Doesn't exit script.</li>


</ul>


## Input

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-utils-launch-editor-for-input/">WP_CLI\Utils\launch_editor_for_input()</a></strong> - Launch system's $EDITOR for the user to edit some text.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-get-flag-value/">WP_CLI\Utils\get_flag_value()</a></strong> - Return the flag value or, if it's not set, the $default value.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-report-batch-operation-results/">WP_CLI\Utils\report_batch_operation_results()</a></strong> - Report the results of the same operation against multiple resources.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-parse-str-to-argv/">WP_CLI\Utils\parse_str_to_argv()</a></strong> - Parse a string of command line arguments into an $argv-esqe variable.</li>


<li><strong><a href="/docs/internal-api/wp-cli-confirm/">WP_CLI::confirm()</a></strong> - Ask for confirmation before running a destructive operation.</li>


<li><strong><a href="/docs/internal-api/wp-cli-read-value/">WP_CLI::read_value()</a></strong> - Read a value, from various formats.</li>


<li><strong><a href="/docs/internal-api/wp-cli-get-config/">WP_CLI::get_config()</a></strong> - Get values of global configuration parameters.</li>


</ul>


## Execution

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-launch/">WP_CLI::launch()</a></strong> - Launch an arbitrary external process that takes over I/O.</li>


<li><strong><a href="/docs/internal-api/wp-cli-launch-self/">WP_CLI::launch_self()</a></strong> - Run a WP-CLI command in a new process reusing the current runtime arguments.</li>


<li><strong><a href="/docs/internal-api/wp-cli-runcommand/">WP_CLI::runcommand()</a></strong> - Run a WP-CLI command.</li>


<li><strong><a href="/docs/internal-api/wp-cli-run-command/">WP_CLI::run_command()</a></strong> - Run a given command within the current process using the same global</li>


</ul>


## System

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-utils-get-temp-dir/">WP_CLI\Utils\get_temp_dir()</a></strong> - Get the system's temp directory. Warns user if it isn't writable.</li>


<li><strong><a href="/docs/internal-api/wp-cli-get-php-binary/">WP_CLI::get_php_binary()</a></strong> - Get the path to the PHP binary used when executing WP-CLI.</li>


</ul>


## Misc

<ul>


<li><strong><a href="/docs/internal-api/wp-cli-utils-write-csv/">WP_CLI\Utils\write_csv()</a></strong> - Write data as CSV to a given file.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-http-request/">WP_CLI\Utils\http_request()</a></strong> - Make a HTTP request to a remote URL.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-get-named-sem-ver/">WP_CLI\Utils\get_named_sem_ver()</a></strong> - Compare two version strings to get the named semantic version.</li>


<li><strong><a href="/docs/internal-api/wp-cli-utils-parse-ssh-url/">WP_CLI\Utils\parse_ssh_url()</a></strong> - Parse a SSH url for its host, port, and path.</li>


</ul>