bdrck 0.9.0

Generic common foundational utilities.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

// Copyright 2015 Axel Rasmussen
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use error::*;
use flags::command::{Command, CommandResult};
use flags::parse_and_execute::parse_and_execute;
use flags::parse_and_execute::parse_and_execute_command;
use std::env;
use std::fmt::{Debug, Display};
use std::process;

pub const EXIT_SUCCESS: i32 = 0;
pub const EXIT_FAILURE: i32 = 1;

/// Returns the current program's parameters (accessed essentialy via
/// `std::env::args`) collected into a Vec. The 0'th parameter (the executable)
/// is omitted.
pub fn get_program_parameters() -> Vec<String> {
    env::args()
        .skip(1) // Skip the first argument, which is our executable.
        .collect()
}

pub fn handle_result<E: Display + Debug>(r: Result<CommandResult<E>>) -> i32 {
    match r {
        Ok(command_result) => match command_result {
            Ok(_) => EXIT_SUCCESS,
            Err(e) => {
                eprintln!(
                    "{}",
                    match cfg!(debug_assertions) {
                        false => e.to_string(),
                        true => format!("{:?}", e),
                    }
                );
                EXIT_FAILURE
            }
        },
        Err(e) => {
            eprintln!(
                "Flag parsing error: {}",
                match cfg!(debug_assertions) {
                    false => e.to_string(),
                    true => format!("{:?}", e),
                }
            );
            EXIT_FAILURE
        }
    }
}

/// Parses command-line parameters and executes the specified command.
///
/// This function exits this process with an appropriate exit code. Like
/// `std::process::exit`, because this function never returns and it terminates
/// the process, no destructors on the current stack or any other thread's
/// stack will be run. The caller should ensure that this function is called
/// from the only thread, and that any destructors which need to be run are in
/// the stack of the command callback.
pub fn main_impl_multiple_commands<E: Display + Debug>(commands: Vec<Command<E>>) -> ! {
    process::exit(handle_result(parse_and_execute_command(
        env::args().next().unwrap().as_ref(),
        &get_program_parameters(),
        commands,
        Some(::std::io::stderr()),
    )));
}

/// Parses command-line parameters and executes the given command.
///
/// This function exits this process with an appropriate exit code. Like
/// `std::process::exit`, because this function never returns and it terminates
/// the process, no destructors on the current stack or any other thread's
/// stack will be run. The caller should ensure that this function is called
/// from the only thread, and that any destructors which need to be run are in
/// the stack of the command callback.
pub fn main_impl_single_command<E: Display + Debug>(command: Command<E>) -> ! {
    process::exit(handle_result(parse_and_execute(
        env::args().next().unwrap().as_ref(),
        &get_program_parameters(),
        command,
        Some(::std::io::stderr()),
    )));
}