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/*
* Copyright (c) 2021 Peter Pentchev <roam@ringlet.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
//! Query a program for its features.
//!
//! The [`obtain_features`] function, when passed
//! a [`Config`][crate::defs::Config] object, will run a program with
//! the appropriate command-line options, analyze its output, and
//! build up a list of the supported features.
//!
//! See the crate-level documentation for sample usage.
use std::collections::HashMap;
use std::error;
use std::process;
use crate::defs;
fn decode_output(output: Vec<u8>) -> Result<String, Box<dyn error::Error>> {
// FIXME: handle non-UTF-8 stuff
Ok(String::from_utf8(output)?)
}
/// Run the specified program, analyze its output.
///
/// See the crate-level documentation for sample usage.
pub fn obtain_features(config: &defs::Config) -> Result<defs::Obtained, Box<dyn error::Error>> {
match process::Command::new(&config.program)
.args(&[&config.option_name])
.output()
{
Ok(output) => match output.status.success() {
true => {
match decode_output(output.stdout)?
.lines()
.find(|line| line.starts_with(&config.prefix))
{
Some(line) => {
let pfx_len = config.prefix.len();
let res: HashMap<String, String> = line[pfx_len..]
.split(' ')
.map(|pair| match pair.find('=') {
Some(pos) => (pair[..pos].to_string(), pair[pos + 1..].to_string()),
None => (pair.to_string(), "1.0".to_string()),
})
.collect();
Ok(defs::Obtained::Features(res))
}
None => Ok(defs::Obtained::NotSupported),
}
}
false => Ok(defs::Obtained::NotSupported),
},
Err(err) => Ok(defs::Obtained::Failed(Box::new(err))),
}
}