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use std::collections::HashMap;
use std::ffi::OsString;
use std::fs;
use std::io::{self, Read};
use std::os::unix::ffi::OsStringExt;
use std::path::{Path, PathBuf};
use std::str;
/// Returns all XDG user directories obtained from $(XDG_CONFIG_HOME)/user-dirs.dirs.
pub fn all(home_dir_path: &Path, user_dir_file_path: &Path) -> HashMap<String, PathBuf> {
let bytes = read_all(user_dir_file_path).unwrap_or(Vec::new());
parse_user_dirs(home_dir_path, None, &bytes)
}
/// Returns a single XDG user directory obtained from $(XDG_CONFIG_HOME)/user-dirs.dirs.
pub fn single(home_dir_path: &Path, user_dir_file_path: &Path, user_dir_name: &str) -> HashMap<String, PathBuf> {
let bytes = read_all(user_dir_file_path).unwrap_or(Vec::new());
parse_user_dirs(home_dir_path, Some(user_dir_name), &bytes)
}
fn parse_user_dirs(home_dir: &Path, user_dir: Option<&str>, bytes: &[u8]) -> HashMap<String, PathBuf> {
let mut user_dirs = HashMap::new();
for line in bytes.split(|b| *b == b'\n') {
let mut single_dir_found = false;
let (key, value) = match split_once(line, b'=') {
Some(kv) => kv,
None => continue,
};
let key = trim_blank(key);
let key = if key.starts_with(b"XDG_") && key.ends_with(b"_DIR") {
match str::from_utf8(&key[4..key.len()-4]) {
Ok(key) =>
if user_dir.is_some() && option_contains(user_dir, key) {
single_dir_found = true;
key
} else if user_dir.is_none() {
key
} else {
continue
},
Err(_) => continue,
}
} else {
continue
};
// xdg-user-dirs-update uses double quotes and we don't support anything else.
let value = trim_blank(value);
let mut value = if value.starts_with(b"\"") && value.ends_with(b"\"") {
&value[1..value.len()-1]
} else {
continue
};
// Path should be either relative to the home directory or absolute.
let is_relative = if value == b"$HOME/" {
// "Note: To disable a directory, point it to the homedir."
// Additionally directory is reassigned to homedir when removed.
continue
} else if value.starts_with(b"$HOME/") {
value = &value[b"$HOME/".len()..];
true
} else if value.starts_with(b"/") {
false
} else {
continue
};
let value = OsString::from_vec(shell_unescape(value));
let path = if is_relative {
let mut path = PathBuf::from(&home_dir);
path.push(value);
path
} else {
PathBuf::from(value)
};
user_dirs.insert(key.to_owned(), path);
if single_dir_found {
break;
}
}
user_dirs
}
/// Reads the entire contents of a file into a byte vector.
fn read_all(path: &Path) -> io::Result<Vec<u8>> {
let mut file = fs::File::open(path)?;
let mut bytes = Vec::with_capacity(1024);
file.read_to_end(&mut bytes)?;
Ok(bytes)
}
/// Returns bytes before and after first occurrence of separator.
fn split_once(bytes: &[u8], separator: u8) -> Option<(&[u8], &[u8])> {
bytes.iter().position(|b| *b == separator).map(|i| {
(&bytes[..i], &bytes[i+1..])
})
}
/// Returns a slice with leading and trailing <blank> characters removed.
fn trim_blank(bytes: &[u8]) -> &[u8] {
// Trim leading <blank> characters.
let i = bytes.iter().cloned().take_while(|b| *b == b' ' || *b == b'\t').count();
let bytes = &bytes[i..];
// Trim trailing <blank> characters.
let i = bytes.iter().cloned().rev().take_while(|b| *b == b' ' || *b == b'\t').count();
&bytes[..bytes.len()-i]
}
/// Unescape bytes escaped with POSIX shell double-quotes rules (as used by xdg-user-dirs-update).
fn shell_unescape(escaped: &[u8]) -> Vec<u8> {
// We assume that byte string was created by xdg-user-dirs-update which
// escapes all characters that might potentially have special meaning,
// so there is no need to check if backslash is actually followed by
// $ ` " \ or a <newline>.
let mut unescaped: Vec<u8> = Vec::with_capacity(escaped.len());
let mut i = escaped.iter().cloned();
while let Some(b) = i.next() {
if b == b'\\' {
if let Some(b) = i.next() {
unescaped.push(b);
}
} else {
unescaped.push(b);
}
}
unescaped
}
fn option_contains<T : PartialEq>(option: Option<T>, value: T) -> bool {
match option {
Some(val) => val == value,
None => false
}
}
#[cfg(test)]
mod tests {
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use super::{trim_blank, shell_unescape, split_once, parse_user_dirs};
#[test]
fn test_trim_blank() {
assert_eq!(b"x", trim_blank(b"x"));
assert_eq!(b"", trim_blank(b" \t "));
assert_eq!(b"hello there", trim_blank(b" \t hello there \t "));
assert_eq!(b"\r\n", trim_blank(b"\r\n"));
}
#[test]
fn test_split_once() {
assert_eq!(None, split_once(b"a b c", b'='));
assert_eq!(Some((b"before".as_ref(), b"after".as_ref())), split_once(b"before=after", b'='));
}
#[test]
fn test_shell_unescape() {
assert_eq!(b"abc", shell_unescape(b"abc").as_slice());
assert_eq!(b"x\\y$z`", shell_unescape(b"x\\\\y\\$z\\`").as_slice());
}
#[test]
fn test_parse_empty() {
assert_eq!(HashMap::new(), parse_user_dirs(Path::new("/root/"), None, b""));
assert_eq!(HashMap::new(), parse_user_dirs(Path::new("/root/"), Some("MUSIC"), b""));
}
#[test]
fn test_absolute_path_is_accepted() {
let mut dirs = HashMap::new();
dirs.insert("MUSIC".to_owned(), PathBuf::from("/media/music"));
let bytes = br#"XDG_MUSIC_DIR="/media/music""#;
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
}
#[test]
fn test_relative_path_is_rejected() {
let dirs = HashMap::new();
let bytes = br#"XDG_MUSIC_DIR="music""#;
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
}
#[test]
fn test_relative_to_home() {
let mut dirs = HashMap::new();
dirs.insert("MUSIC".to_owned(), PathBuf::from("/home/john/Music"));
let bytes = br#"XDG_MUSIC_DIR="$HOME/Music""#;
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
}
#[test]
fn test_disabled_directory() {
let dirs = HashMap::new();
let bytes = br#"XDG_MUSIC_DIR="$HOME/""#;
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), None, bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/john"), Some("MUSIC"), bytes));
}
#[test]
fn test_parse_user_dirs() {
let mut dirs: HashMap<String, PathBuf> = HashMap::new();
dirs.insert("DESKTOP".to_string(), PathBuf::from("/home/bob/Desktop"));
dirs.insert("DOWNLOAD".to_string(), PathBuf::from("/home/bob/Downloads"));
dirs.insert("PICTURES".to_string(), PathBuf::from("/home/eve/pics"));
let bytes = br#"
# This file is written by xdg-user-dirs-update
# If you want to change or add directories, just edit the line you're
# interested in. All local changes will be retained on the next run.
# Format is XDG_xxx_DIR="$HOME/yyy", where yyy is a shell-escaped
# homedir-relative path, or XDG_xxx_DIR="/yyy", where /yyy is an
# absolute path. No other format is supported.
XDG_DESKTOP_DIR="$HOME/Desktop"
XDG_DOWNLOAD_DIR="$HOME/Downloads"
XDG_TEMPLATES_DIR=""
XDG_PUBLICSHARE_DIR="$HOME"
XDG_DOCUMENTS_DIR="$HOME/"
XDG_PICTURES_DIR="/home/eve/pics"
XDG_VIDEOS_DIR="$HOxyzME/Videos"
"#;
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), None, bytes));
let mut dirs: HashMap<String, PathBuf> = HashMap::new();
dirs.insert("DESKTOP".to_string(), PathBuf::from("/home/bob/Desktop"));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("DESKTOP"), bytes));
let mut dirs: HashMap<String, PathBuf> = HashMap::new();
dirs.insert("PICTURES".to_string(), PathBuf::from("/home/eve/pics"));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("PICTURES"), bytes));
let dirs: HashMap<String, PathBuf> = HashMap::new();
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("TEMPLATES"), bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("PUBLICSHARE"), bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("DOCUMENTS"), bytes));
assert_eq!(dirs, parse_user_dirs(Path::new("/home/bob"), Some("VIDEOS"), bytes));
}
}