overgrown/src/getopt.rs

116 lines
3.1 KiB
Rust

/*
* Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
* SPDX-License-Identifier: LGPL-3.0-or-later
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see https://www.gnu.org/licenses/.
*/
use std::ffi::{ c_int, c_char, CString };
pub struct Opt {
pub arg: Option<String>,
pub ind: i32,
pub opt: i32,
}
pub enum OptError {
MissingArg,
UnknownOpt,
}
// Function signature
pub trait GetOpt {
fn getopt(
argv: Vec<String>,
optstring: &str
) -> Option<Result<Opt, OptError>>;
}
impl GetOpt for Vec<String> {
fn getopt(
argv: Vec<String>,
optstring: &str
) -> Option<Result<Opt, OptError>> {
unsafe {
let args = argv
.iter()
.cloned()
.map(CString::new)
.map(Result::unwrap)
.map(|x| x.as_ptr() as c_char)
.collect::<Vec<c_char>>()
.as_ptr() as *const *mut c_char;
let len = argv.len() as c_int;
let opts = CString::new(optstring).unwrap().into_raw();
let a = match getopt(len, args, opts) {
/* From getopt(3p):
*
* The getopt() function shall return the next option character
* specified on the command line.
*
* A <colon> (':') shall be returned if getopt() detects a
* missing argument and the first character of optstring was a
* <colon> (':').
*
* A <question-mark> ('?') shall be returned if getopt()
* encounters an option character not in optstring or detects a
* missing argument and the first character of optstring was not
* a <colon> (':').
*
* Otherwise, getopt() shall return -1 when all command line
* options are parsed. */
58 => { // ASCII value for ':'
return Some(Err(OptError::MissingArg));
},
63 => { // ASCII value for '?'
return Some(Err(OptError::UnknownOpt));
},
/* From getopt(3p):
*
* If, when getopt() is called:
*
* argv[optind] is a null pointer
* *argv[optind] is not the character -
* argv[optind] points to the string "-"
*
* getopt() shall return -1 without changing optind. If:
*
* argv[optind] points to the string "--"
*
* getopt() shall return -1 after incrementing optind. */
-1 => return None,
a => a.to_string(),
};
Some(Ok(Opt { arg: Some(a), ind: optind, opt: optopt }))
}
}
}
/* binding to getopt(3p) */
extern "C" {
static mut _optarg: *mut c_char;
static mut _opterr: c_int;
static mut optind: c_int;
static mut optopt: c_int;
fn getopt(
___argc: c_int,
___argv: *const *mut c_char,
__shortopts: *const c_char,
) -> c_int;
}