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 { let bytes = read_all(user_dir_file_path).unwrap_or_default(); parse_user_dirs(home_dir_path, None, &bytes) } /// Returns a single XDG user directory obtained from $(XDG_CONFIG_HOME)/user-dirs.dirs. pub fn single(home_dir_path: &Path, user_dir_file_path: &Path, user_dir_name: &str) -> HashMap { let bytes = read_all(user_dir_file_path).unwrap_or_default(); parse_user_dirs(home_dir_path, Some(user_dir_name), &bytes) } fn parse_user_dirs(home_dir: &Path, user_dir: Option<&str>, bytes: &[u8]) -> HashMap { let mut user_dirs = HashMap::new(); for line in bytes.split(|b| *b == b'\n') { let mut single_dir_found = false; let (key, value) = match split_once(line, b'=') { Some(kv) => kv, None => continue, }; let key = trim_blank(key); let key = if key.starts_with(b"XDG_") && key.ends_with(b"_DIR") { match str::from_utf8(&key[4..key.len() - 4]) { Ok(key) => { if user_dir.is_some() && option_contains(user_dir, key) { single_dir_found = true; key } else if user_dir.is_none() { key } else { continue; } } Err(_) => continue, } } else { continue; }; // xdg-user-dirs-update uses double quotes and we don't support anything else. let value = trim_blank(value); let mut value = if value.starts_with(b"\"") && value.ends_with(b"\"") { &value[1..value.len() - 1] } else { continue }; // Path should be either relative to the home directory or absolute. let is_relative = if value == b"$HOME/" { // "Note: To disable a directory, point it to the homedir." // Source: https://www.freedesktop.org/wiki/Software/xdg-user-dirs/ // 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> { 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 characters removed. fn trim_blank(bytes: &[u8]) -> &[u8] { // Trim leading characters. let i = bytes.iter().cloned().take_while(|b| *b == b' ' || *b == b'\t').count(); let bytes = &bytes[i..]; // Trim trailing 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 { // 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 . let mut unescaped: Vec = 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(option: Option, value: T) -> bool { match option { Some(val) => val == value, None => false, } } #[cfg(test)] mod tests { use super::{parse_user_dirs, shell_unescape, split_once, trim_blank}; use std::collections::HashMap; use std::path::{Path, PathBuf}; #[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 = 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 = 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 = 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 = 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)); } }