vendor/shell-escape/src/lib.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10 //! Escape characters that may have special meaning in a shell.
  11 #![doc(html_root_url="https://docs.rs/shell-escape/0.1")]
  12
  13 use std::borrow::Cow;
  14 use std::env;
  15
  16 /// Escape characters that may have special meaning in a shell.
  17 pub fn escape(s: Cow<str>) -> Cow<str> {
  18     if cfg!(unix) || env::var("MSYSTEM").is_ok() {
  19         unix::escape(s)
  20     } else {
  21         windows::escape(s)
  22     }
  23 }
  24
  25 /// Windows-specific escaping.
  26 pub mod windows {
  27     use std::borrow::Cow;
  28     use std::iter::repeat;
  29
  30     /// Escape for the windows cmd.exe shell.
  31     ///
  32     /// See [here][msdn] for more information.
  33     ///
  34     /// [msdn]: http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx
  35     pub fn escape(s: Cow<str>) -> Cow<str> {
  36         let mut needs_escape = s.is_empty();
  37         for ch in s.chars() {
  38             match ch {
  39                 '"' | '\t' | '\n' | ' ' => needs_escape = true,
  40                 _ => {}
  41             }
  42         }
  43         if !needs_escape {
  44             return s
  45         }
  46         let mut es = String::with_capacity(s.len());
  47         es.push('"');
  48         let mut chars = s.chars().peekable();
  49         loop {
  50             let mut nslashes = 0;
  51             while let Some(&'\\') = chars.peek() {
  52                 chars.next();
  53                 nslashes += 1;
  54             }
  55
  56             match chars.next() {
  57                 Some('"') => {
  58                     es.extend(repeat('\\').take(nslashes * 2 + 1));
  59                     es.push('"');
  60                 }
  61                 Some(c) => {
  62                     es.extend(repeat('\\').take(nslashes));
  63                     es.push(c);
  64                 }
  65                 None => {
  66                     es.extend(repeat('\\').take(nslashes * 2));
  67                     break;
  68                 }
  69             }
  70
  71         }
  72         es.push('"');
  73         es.into()
  74     }
  75
  76     #[test]
  77     fn test_escape() {
  78         assert_eq!(escape("--aaa=bbb-ccc".into()), "--aaa=bbb-ccc");
  79         assert_eq!(escape("linker=gcc -L/foo -Wl,bar".into()),
  80         r#""linker=gcc -L/foo -Wl,bar""#);
  81         assert_eq!(escape(r#"--features="default""#.into()),
  82         r#""--features=\"default\"""#);
  83         assert_eq!(escape(r#"\path\to\my documents\"#.into()),
  84         r#""\path\to\my documents\\""#);
  85         assert_eq!(escape("".into()), r#""""#);
  86     }
  87 }
  88
  89 /// Unix-specific escaping.
  90 pub mod unix {
  91     use std::borrow::Cow;
  92
  93     fn non_whitelisted(ch: char) -> bool {
  94         match ch {
  95             'a'...'z' | 'A'...'Z' | '0'...'9' | '-' | '_' | '=' | '/' | ',' | '.' | '+' => false,
  96             _ => true,
  97         }
  98     }
  99
 100     /// Escape characters that may have special meaning in a shell, including spaces.
 101     pub fn escape(s: Cow<str>) -> Cow<str> {
 102         if !s.is_empty() && !s.contains(non_whitelisted) {
 103             return s;
 104         }
 105
 106         let mut es = String::with_capacity(s.len() + 2);
 107         es.push('\'');
 108         for ch in s.chars() {
 109             match ch {
 110                 '\'' | '!' => {
 111                     es.push_str("'\\");
 112                     es.push(ch);
 113                     es.push('\'');
 114                 }
 115                 _ => es.push(ch),
 116             }
 117         }
 118         es.push('\'');
 119         es.into()
 120     }
 121
 122     #[test]
 123     fn test_escape() {
 124         assert_eq!(
 125             escape("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_=/,.+".into()),
 126             "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_=/,.+"
 127         );
 128         assert_eq!(escape("--aaa=bbb-ccc".into()), "--aaa=bbb-ccc");
 129         assert_eq!(escape("linker=gcc -L/foo -Wl,bar".into()), r#"'linker=gcc -L/foo -Wl,bar'"#);
 130         assert_eq!(escape(r#"--features="default""#.into()), r#"'--features="default"'"#);
 131         assert_eq!(escape(r#"'!\$`\\\n "#.into()), r#"''\'''\!'\$`\\\n '"#);
 132         assert_eq!(escape("".into()), r#"''"#);
 133     }
 134 }
 135