1use std::collections::HashMap;
2use std::ffi::OsString;
3use std::fs;
4use std::io::{self, Read};
5use std::os::unix::ffi::OsStringExt;
6use std::path::{Path, PathBuf};
7use std::str;
8
9/// Returns all XDG user directories obtained from $(XDG_CONFIG_HOME)/user-dirs.dirs.
10pub fn all(home_dir_path: &Path, user_dir_file_path: &Path) -> HashMap<String, PathBuf> {
11 let bytes: Vec = read_all(user_dir_file_path).unwrap_or_default();
12 parse_user_dirs(home_dir_path, user_dir:None, &bytes)
13}
14
15/// Returns a single XDG user directory obtained from $(XDG_CONFIG_HOME)/user-dirs.dirs.
16pub fn single(home_dir_path: &Path, user_dir_file_path: &Path, user_dir_name: &str) -> HashMap<String, PathBuf> {
17 let bytes: Vec = read_all(user_dir_file_path).unwrap_or_default();
18 parse_user_dirs(home_dir_path, user_dir:Some(user_dir_name), &bytes)
19}
20
21fn parse_user_dirs(home_dir: &Path, user_dir: Option<&str>, bytes: &[u8]) -> HashMap<String, PathBuf> {
22 let mut user_dirs = HashMap::new();
23
24 for line in bytes.split(|b| *b == b'\n') {
25 let mut single_dir_found = false;
26 let (key, value) = match split_once(line, b'=') {
27 Some(kv) => kv,
28 None => continue,
29 };
30
31 let key = trim_blank(key);
32 let key = if key.starts_with(b"XDG_") && key.ends_with(b"_DIR") {
33 match str::from_utf8(&key[4..key.len() - 4]) {
34 Ok(key) => {
35 if user_dir.is_some() && option_contains(user_dir, key) {
36 single_dir_found = true;
37 key
38 } else if user_dir.is_none() {
39 key
40 } else {
41 continue;
42 }
43 }
44 Err(_) => continue,
45 }
46 } else {
47 continue;
48 };
49
50 // xdg-user-dirs-update uses double quotes and we don't support anything else.
51 let value = trim_blank(value);
52 let mut value =
53 if value.starts_with(b"\"") && value.ends_with(b"\"") { &value[1..value.len() - 1] } else { continue };
54
55 // Path should be either relative to the home directory or absolute.
56 let is_relative = if value == b"$HOME/" {
57 // "Note: To disable a directory, point it to the homedir."
58 // Source: https://www.freedesktop.org/wiki/Software/xdg-user-dirs/
59 // Additionally directory is reassigned to homedir when removed.
60 continue;
61 } else if value.starts_with(b"$HOME/") {
62 value = &value[b"$HOME/".len()..];
63 true
64 } else if value.starts_with(b"/") {
65 false
66 } else {
67 continue;
68 };
69
70 let value = OsString::from_vec(shell_unescape(value));
71
72 let path = if is_relative {
73 let mut path = PathBuf::from(&home_dir);
74 path.push(value);
75 path
76 } else {
77 PathBuf::from(value)
78 };
79
80 user_dirs.insert(key.to_owned(), path);
81 if single_dir_found {
82 break;
83 }
84 }
85
86 user_dirs
87}
88
89/// Reads the entire contents of a file into a byte vector.
90fn read_all(path: &Path) -> io::Result<Vec<u8>> {
91 let mut file: File = fs::File::open(path)?;
92 let mut bytes: Vec = Vec::with_capacity(1024);
93 file.read_to_end(&mut bytes)?;
94 Ok(bytes)
95}
96
97/// Returns bytes before and after first occurrence of separator.
98fn split_once(bytes: &[u8], separator: u8) -> Option<(&[u8], &[u8])> {
99 bytes.iter().position(|b: &u8| *b == separator).map(|i: usize| (&bytes[..i], &bytes[i + 1..]))
100}
101
102/// Returns a slice with leading and trailing <blank> characters removed.
103fn trim_blank(bytes: &[u8]) -> &[u8] {
104 // Trim leading <blank> characters.
105 let i: usize = bytes.iter().cloned().take_while(|b: &u8| *b == b' ' || *b == b'\t').count();
106 let bytes: &[u8] = &bytes[i..];
107
108 // Trim trailing <blank> characters.
109 let i: usize = bytes.iter().cloned().rev().take_while(|b: &u8| *b == b' ' || *b == b'\t').count();
110 &bytes[..bytes.len() - i]
111}
112
113/// Unescape bytes escaped with POSIX shell double-quotes rules (as used by xdg-user-dirs-update).
114fn shell_unescape(escaped: &[u8]) -> Vec<u8> {
115 // We assume that byte string was created by xdg-user-dirs-update which
116 // escapes all characters that might potentially have special meaning,
117 // so there is no need to check if backslash is actually followed by
118 // $ ` " \ or a <newline>.
119
120 let mut unescaped: Vec<u8> = Vec::with_capacity(escaped.len());
121 let mut i: impl Iterator = escaped.iter().cloned();
122
123 while let Some(b: u8) = i.next() {
124 if b == b'\\' {
125 if let Some(b: u8) = i.next() {
126 unescaped.push(b);
127 }
128 } else {
129 unescaped.push(b);
130 }
131 }
132
133 unescaped
134}
135
136fn option_contains<T: PartialEq>(option: Option<T>, value: T) -> bool {
137 match option {
138 Some(val: T) => val == value,
139 None => false,
140 }
141}
142
143#[cfg(test)]
144mod tests {
145 use super::{parse_user_dirs, shell_unescape, split_once, trim_blank};
146 use std::collections::HashMap;
147 use std::path::{Path, PathBuf};
148
149 #[test]
150 fn test_trim_blank() {
151 assert_eq!(b"x", trim_blank(b"x"));
152 assert_eq!(b"", trim_blank(b" \t "));
153 assert_eq!(b"hello there", trim_blank(b" \t hello there \t "));
154 assert_eq!(b"\r\n", trim_blank(b"\r\n"));
155 }
156
157 #[test]
158 fn test_split_once() {
159 assert_eq!(None, split_once(b"a b c", b'='));
160 assert_eq!(Some((b"before".as_ref(), b"after".as_ref())), split_once(b"before=after", b'='));
161 }
162
163 #[test]
164 fn test_shell_unescape() {
165 assert_eq!(b"abc", shell_unescape(b"abc").as_slice());
166 assert_eq!(b"x\\y$z`", shell_unescape(b"x\\\\y\\$z\\`").as_slice());
167 }
168
169 #[test]
170 fn test_parse_empty() {
171 assert_eq!(HashMap::new(), parse_user_dirs(Path::new("/root/"), None, b""));
172 assert_eq!(HashMap::new(), parse_user_dirs(Path::new("/root/"), Some("MUSIC"), b""));
173 }
174
175 #[test]
176 fn test_absolute_path_is_accepted() {
177 let mut dirs = HashMap::new();
178 dirs.insert("MUSIC".to_owned(), PathBuf::from("/media/music"));
179 let bytes = br#"XDG_MUSIC_DIR="/media/music""#;
180 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
181 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
182 }
183
184 #[test]
185 fn test_relative_path_is_rejected() {
186 let dirs = HashMap::new();
187 let bytes = br#"XDG_MUSIC_DIR="music""#;
188 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
189 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
190 }
191
192 #[test]
193 fn test_relative_to_home() {
194 let mut dirs = HashMap::new();
195 dirs.insert("MUSIC".to_owned(), PathBuf::from("/home/john/Music"));
196 let bytes = br#"XDG_MUSIC_DIR="$HOME/Music""#;
197 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
198 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
199 }
200
201 #[test]
202 fn test_disabled_directory() {
203 let dirs = HashMap::new();
204 let bytes = br#"XDG_MUSIC_DIR="$HOME/""#;
205 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
206 assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
207 }
208
209 #[test]
210 fn test_parse_user_dirs() {
211 let mut dirs: HashMap<String, PathBuf> = HashMap::new();
212 dirs.insert("DESKTOP".to_string(), PathBuf::from("/home/bob/Desktop"));
213 dirs.insert("DOWNLOAD".to_string(), PathBuf::from("/home/bob/Downloads"));
214 dirs.insert("PICTURES".to_string(), PathBuf::from("/home/eve/pics"));
215
216 let bytes = br#"
217# This file is written by xdg-user-dirs-update
218# If you want to change or add directories, just edit the line you're
219# interested in. All local changes will be retained on the next run.
220# Format is XDG_xxx_DIR="$HOME/yyy", where yyy is a shell-escaped
221# homedir-relative path, or XDG_xxx_DIR="/yyy", where /yyy is an
222# absolute path. No other format is supported.
223XDG_DESKTOP_DIR="$HOME/Desktop"
224XDG_DOWNLOAD_DIR="$HOME/Downloads"
225XDG_TEMPLATES_DIR=""
226XDG_PUBLICSHARE_DIR="$HOME"
227XDG_DOCUMENTS_DIR="$HOME/"
228XDG_PICTURES_DIR="/home/eve/pics"
229XDG_VIDEOS_DIR="$HOxyzME/Videos"
230"#;
231
232 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), None, bytes));
233
234 let mut dirs: HashMap<String, PathBuf> = HashMap::new();
235 dirs.insert("DESKTOP".to_string(), PathBuf::from("/home/bob/Desktop"));
236 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("DESKTOP"), bytes));
237
238 let mut dirs: HashMap<String, PathBuf> = HashMap::new();
239 dirs.insert("PICTURES".to_string(), PathBuf::from("/home/eve/pics"));
240 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("PICTURES"), bytes));
241
242 let dirs: HashMap<String, PathBuf> = HashMap::new();
243 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("TEMPLATES"), bytes));
244 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("PUBLICSHARE"), bytes));
245 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("DOCUMENTS"), bytes));
246 assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("VIDEOS"), bytes));
247 }
248}
249