fish-shell/printf/README.md

fish-printf

The printf implementation used in fish-shell, based on musl printf.

Licensed under the MIT license.

Usage

Run cargo add fish-printf to add this crate to your Cargo.toml file.

Notes

fish-printf attempts to match the C standard for printf. It supports the following features:

• Locale-specific formatting (decimal point, thousands separator, etc.)
• Honors the current rounding mode.
• Supports the %n modifier for counting characters written.

fish-printf does not support positional arguments, such as printf("%2$d", 1, 2).

Prefixes like l or ll are recognized, but only used for validating the format string.
The size of integer values is taken from the argument type.

fish-printf can output to an std::fmt::Write object, or return a string.

For reasons related to fish-shell, fish-printf has a feature "widestring" which uses the widestring crate. This is off by default. If enabled, run cargo add widestring to add the widestring crate.

Examples

use fish_printf::sprintf;

// Create a `String` from a format string.
let s = sprintf!("%0.5g", 123456.0) // 1.2346e+05

// Append to an existing string.
let mut s = String::new();
sprintf!(=> &mut s, "%0.5g", 123456.0) // 1.2346e+05

See the crate documentation for additional examples.