shell_escape/
lib.rs

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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Escape characters that may have special meaning in a shell.
#![doc(html_root_url="https://docs.rs/shell-escape/0.1")]

use std::borrow::Cow;
use std::env;

/// Escape characters that may have special meaning in a shell.
pub fn escape(s: Cow<str>) -> Cow<str> {
    if cfg!(unix) || env::var("MSYSTEM").is_ok() {
        unix::escape(s)
    } else {
        windows::escape(s)
    }
}

/// Windows-specific escaping.
pub mod windows {
    use std::borrow::Cow;
    use std::iter::repeat;

    /// Escape for the windows cmd.exe shell.
    ///
    /// See [here][msdn] for more information.
    ///
    /// [msdn]: http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx
    pub fn escape(s: Cow<str>) -> Cow<str> {
        let mut needs_escape = s.is_empty();
        for ch in s.chars() {
            match ch {
                '"' | '\t' | '\n' | ' ' => needs_escape = true,
                _ => {}
            }
        }
        if !needs_escape {
            return s
        }
        let mut es = String::with_capacity(s.len());
        es.push('"');
        let mut chars = s.chars().peekable();
        loop {
            let mut nslashes = 0;
            while let Some(&'\\') = chars.peek() {
                chars.next();
                nslashes += 1;
            }

            match chars.next() {
                Some('"') => {
                    es.extend(repeat('\\').take(nslashes * 2 + 1));
                    es.push('"');
                }
                Some(c) => {
                    es.extend(repeat('\\').take(nslashes));
                    es.push(c);
                }
                None => {
                    es.extend(repeat('\\').take(nslashes * 2));
                    break;
                }
            }

        }
        es.push('"');
        es.into()
    }

    #[test]
    fn test_escape() {
        assert_eq!(escape("--aaa=bbb-ccc".into()), "--aaa=bbb-ccc");
        assert_eq!(escape("linker=gcc -L/foo -Wl,bar".into()),
        r#""linker=gcc -L/foo -Wl,bar""#);
        assert_eq!(escape(r#"--features="default""#.into()),
        r#""--features=\"default\"""#);
        assert_eq!(escape(r#"\path\to\my documents\"#.into()),
        r#""\path\to\my documents\\""#);
        assert_eq!(escape("".into()), r#""""#);
    }
}

/// Unix-specific escaping.
pub mod unix {
    use std::borrow::Cow;

    fn non_whitelisted(ch: char) -> bool {
        match ch {
            'a'...'z' | 'A'...'Z' | '0'...'9' | '-' | '_' | '=' | '/' | ',' | '.' | '+' => false,
            _ => true,
        }
    }

    /// Escape characters that may have special meaning in a shell, including spaces.
    pub fn escape(s: Cow<str>) -> Cow<str> {
        if !s.is_empty() && !s.contains(non_whitelisted) {
            return s;
        }

        let mut es = String::with_capacity(s.len() + 2);
        es.push('\'');
        for ch in s.chars() {
            match ch {
                '\'' | '!' => {
                    es.push_str("'\\");
                    es.push(ch);
                    es.push('\'');
                }
                _ => es.push(ch),
            }
        }
        es.push('\'');
        es.into()
    }

    #[test]
    fn test_escape() {
        assert_eq!(
            escape("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_=/,.+".into()),
            "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_=/,.+"
        );
        assert_eq!(escape("--aaa=bbb-ccc".into()), "--aaa=bbb-ccc");
        assert_eq!(escape("linker=gcc -L/foo -Wl,bar".into()), r#"'linker=gcc -L/foo -Wl,bar'"#);
        assert_eq!(escape(r#"--features="default""#.into()), r#"'--features="default"'"#);
        assert_eq!(escape(r#"'!\$`\\\n "#.into()), r#"''\'''\!'\$`\\\n '"#);
        assert_eq!(escape("".into()), r#"''"#);
    }
}