Struct Getopt 

pub struct Getopt {
    pub optind: usize,
    pub optopt: char,
    pub optarg: Option<String>,
    pub opterr: bool,
    /* private fields */
}

A BSD-style command-line option parser.

Getopt iterates over command-line arguments and returns options one by one, mimicking the behavior of traditional Unix getopt.

The parser maintains internal state such as:

• optind: index of the next argument to process
• optarg: argument associated with the current option (if any)
• optopt: the last option character processed
• opterr: whether to print error messages

Example

use bsd_getopt::Getopt;

let args = vec![
    "prog".to_string(),
    "-a".to_string(),
    "-bvalue".to_string(),
];

let mut g = Getopt::new("ab:", args);

assert_eq!(g.next(), Some('a'));
assert_eq!(g.next(), Some('b'));
assert_eq!(g.optarg, Some("value".to_string()));
assert_eq!(g.next(), None);

Fields

optind: usize

optopt: char

optarg: Option<String>

opterr: bool

Implementations

impl Getopt

pub fn new(optstring: &str, args: Vec<String>) -> Self

Creates a new Getopt parser.

Parameters

• optstring: A string describing valid options.
• args: Command-line arguments (typically from std::env::args()).

Behavior

• Parsing starts from index 1 (skipping program name)
• Internal state is initialized to default values

Example

use bsd_getopt::Getopt;

let args = vec!["prog".to_string(), "-a".to_string()];
let parser = Getopt::new("a", args);

pub fn next(&mut self) -> Option<char>

Returns the next option character, or None if parsing is complete.

This function mimics the behavior of the standard getopt:

• Returns Some(char) for a valid option
• Returns Some('?') for an unknown option
• Returns Some(':') if an argument is missing and optstring starts with :
• Returns None when no more options are available

Side Effects

• Updates optind, optarg, and optopt
• May print errors to stderr if opterr is true

Rules

• Options can be grouped: -abc
• Options with arguments:
  • -o value
  • -ovalue
• -- stops option parsing

Example

use bsd_getopt::Getopt;

let args = vec![
    "prog".to_string(),
    "-a".to_string(),
    "-b".to_string(),
    "foo".to_string(),
];

let mut g = Getopt::new("ab:", args);

assert_eq!(g.next(), Some('a'));
assert_eq!(g.next(), Some('b'));
assert_eq!(g.optarg, Some("foo".to_string()));
assert_eq!(g.next(), None);

Trait Implementations

impl Clone for Getopt

fn clone(&self) -> Getopt

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Getopt

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

Formats the value using the given formatter.