Struct HelpFormatter 

pub struct HelpFormatter { /* private fields */ }

Help text formatter with terminal-aware wrapping.

This struct provides methods for formatting help text with proper indentation, text wrapping, and special formatting for definition lists (options/arguments).

Example

use click::HelpFormatter;

let mut formatter = HelpFormatter::new(80);

formatter.write_usage("mycli", "[OPTIONS] COMMAND");
formatter.write_paragraph("A helpful CLI tool.");
formatter.write_heading("Options");
formatter.write_definition_list(&[
    ("--help, -h", "Show this help message"),
    ("--verbose, -v", "Enable verbose output"),
]);

println!("{}", formatter.get_help());

Implementations

impl HelpFormatter

pub fn new(width: usize) -> Self

Create a new HelpFormatter with the specified terminal width.

If width is 0 or less than minimum, uses default width.

pub fn detect_width() -> Self

Create a new HelpFormatter that detects terminal width.

pub fn get_help(&self) -> &str

Get the accumulated help text.

pub fn into_help(self) -> String

Consume the formatter and return the help text.

pub fn width(&self) -> usize

Get the current terminal width.

pub fn set_indent(&mut self, indent: usize)

Set the current indentation level.

pub fn indent(&mut self, amount: usize)

Increase indentation by the given amount.

pub fn dedent(&mut self, amount: usize)

Decrease indentation by the given amount.

pub fn write_blank(&mut self)

Write a blank line.

pub fn write_raw(&mut self, text: &str)

Write raw text without any processing.

pub fn write(&mut self, text: &str)

Write text with the current indentation.

pub fn write_usage(&mut self, prog: &str, args: &str)

Write a usage line.

Format: Usage: prog [OPTIONS] ARGS

pub fn write_heading(&mut self, heading: &str)

Write a section heading.

The heading is followed by a blank line.

pub fn write_paragraph(&mut self, text: &str)

Write a paragraph of text with word wrapping.

Preserves paragraph breaks (double newlines) and wraps text to fit within the terminal width.

pub fn write_definition_list(&mut self, items: &[(&str, &str)])

Write a definition list (term + description pairs).

Used for formatting options and arguments. Each item is a tuple of (term, description).

Format depends on term length:

• Short terms: description on same line
• Long terms: description on next line, indented

pub fn write_definition_list_strings(&mut self, items: &[(String, String)])

Write a definition list with string tuples.

Trait Implementations

impl Debug for HelpFormatter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for HelpFormatter

fn default() -> Self

Returns the “default value” for a type.