Struct AppPath

pub struct AppPath { /* private fields */ }

Creates paths relative to the executable location for portable applications.

AppPath enables building truly portable applications where configuration, data, and executable stay together as a deployable unit. Perfect for USB drives, network shares, or any directory without installation.

Key Features

• Portable: Relative paths resolve to executable directory
• System integration: Absolute paths work as-is
• Zero-cost: Implements Deref<Target=Path> and all path traits
• Thread-safe: Static caching with proper synchronization
• Memory efficient: Only stores the final resolved path

API Overview

• Self::new() - Primary API: Simple, infallible construction
• Self::try_new() - Libraries: Fallible version for error handling
• Self::with_override() - Deployment: Environment-configurable paths
• Self::path() - Access: Get the resolved &Path

Panics

Methods panic if executable location cannot be determined (extremely rare). After first successful call, methods never panic (uses cached result).

Examples

use app_path::AppPath;

// Basic usage - most common pattern
let config = AppPath::new("config.toml");
let data = AppPath::new("data/users.db");

// Works like standard paths
if config.exists() {
    let content = std::fs::read_to_string(&config);
}
data.create_dir_all(); // Creates data/ directory

// Mixed portable and system paths
let portable = AppPath::new("app.conf");           // → exe_dir/app.conf
let system = AppPath::new("/var/log/app.log");     // → /var/log/app.log

// Override for deployment flexibility
let config = AppPath::with_override(
    "config.toml",
    std::env::var("CONFIG_PATH").ok()
);

Implementations

impl AppPath

pub fn new(path: impl AsRef<Path>) -> Self

Creates file paths relative to the executable location.

Recommended for most applications. This is the simple, infallible API that handles the common case cleanly without error handling boilerplate.

Path Resolution

• Relative paths: "config.toml" → exe_dir/config.toml (portable)
• Absolute paths: "/etc/config" → /etc/config (system integration)

Performance

• Static caching: Executable location determined once, reused forever
• Zero allocations: Efficient path resolution
• Thread-safe: Safe to call from multiple threads

Panics

Panics if executable location cannot be determined (extremely rare):

• std::env::current_exe() fails
• Executable path is empty (system corruption)

After first successful call, this method never panics (uses cached result).

Examples

use app_path::AppPath;

// Most common usage
let config = AppPath::new("config.toml");
let data = AppPath::new("data/users.db");
let logs = AppPath::new("logs/app.log");

// Mixed portable and system paths
let app_config = AppPath::new("config.toml");           // → exe_dir/config.toml
let system_log = AppPath::new("/var/log/myapp.log");    // → /var/log/myapp.log

// Use like normal paths
if config.exists() {
    let content = std::fs::read_to_string(&config);
}
data.create_dir_all(); // Creates data/ directory

Panics

Panics on first use if the executable location cannot be determined. This is extremely rare and indicates fundamental system issues. See AppPathError for details on the possible failure conditions.

After the first successful call, this method will never panic as it uses the cached result.

Performance

This method is highly optimized:

• Static caching: Executable location determined once, reused forever
• Zero allocations: Uses AsRef<Path> to avoid unnecessary conversions
• Minimal memory: Only stores the final resolved path
• Thread-safe: Safe to call from multiple threads concurrently

Examples

use app_path::AppPath;

// Most common usage
let config = AppPath::new("config.toml");
let data = AppPath::new("data/users.db");
let logs = AppPath::new("logs/app.log");

// Mixed portable and system paths
let app_config = AppPath::new("config.toml");           // → exe_dir/config.toml
let system_log = AppPath::new("/var/log/myapp.log");    // → /var/log/myapp.log

// Use like normal paths
if config.exists() {
    let content = std::fs::read_to_string(&config);
}
data.create_dir_all(); // Creates data/ directory

pub fn try_new(path: impl AsRef<Path>) -> Result<Self, AppPathError>

Creates file paths relative to the executable location (fallible).

Use this only for libraries or specialized applications requiring explicit error handling. Most applications should use Self::new() instead for simpler, cleaner code.

When to Use

Use try_new() for:

• Reusable libraries that shouldn’t panic
• System tools with fallback strategies
• Applications running in unusual environments

Use Self::new() for:

• Desktop, web, server, CLI applications
• When you want simple, clean code (recommended)

Examples

use app_path::{AppPath, AppPathError};

// Library with graceful error handling
fn load_config() -> Result<String, AppPathError> {
    let config_path = AppPath::try_new("config.toml")?;
    // Load configuration...
    Ok("config loaded".to_string())
}

// Better: Use override API for environment variables
fn load_config_with_override() -> Result<String, AppPathError> {
    let config_path = AppPath::try_with_override(
        "config.toml",
        std::env::var("APP_CONFIG").ok()
    )?;
    // Load configuration...
    Ok("config loaded".to_string())
}

// Multiple environment variable fallback (better approach)
fn get_config_with_fallback() -> Result<AppPath, AppPathError> {
    AppPath::try_with_override_fn("config.toml", || {
        std::env::var("APP_CONFIG").ok()
            .or_else(|| std::env::var("CONFIG_FILE").ok())
            .or_else(|| std::env::var("XDG_CONFIG_HOME").ok().map(|dir| format!("{}/myapp/config.toml", dir)))
    })
}

Reality check: Executable location determination failing is extremely rare:

• It requires fundamental system issues or unusual deployment scenarios
• When it happens, it usually indicates unrecoverable system problems
• Most applications can’t meaningfully continue without knowing their location
• The error handling overhead isn’t worth it for typical applications

Better approaches for most applications:

use app_path::AppPath;
use std::env;

// Use our override API for environment variables (recommended)
fn get_config_path() -> AppPath {
    AppPath::with_override("config.toml", env::var("MYAPP_CONFIG_DIR").ok())
}

// Or fallible version for libraries
fn try_get_config_path() -> Result<AppPath, app_path::AppPathError> {
    AppPath::try_with_override("config.toml", env::var("MYAPP_CONFIG_DIR").ok())
}

Global Caching Behavior

Once the executable directory is successfully determined by either this method or AppPath::new(), the result is cached globally and all subsequent calls to both methods will use the cached value. This means that after the first successful call, try_new() will never return an error.

Arguments

• path - A path that will be resolved according to AppPath’s resolution strategy. Accepts any type implementing AsRef<Path>.

Returns

• Ok(AppPath) - Successfully created AppPath with resolved path
• Err(AppPathError) - Failed to determine executable location (extremely rare)

Examples

Library Error Handling

use app_path::{AppPath, AppPathError};

// Library function that returns Result instead of panicking
pub fn create_config_manager() -> Result<ConfigManager, AppPathError> {
    let config_path = AppPath::try_new("config.toml")?;
    Ok(ConfigManager::new(config_path))
}

pub struct ConfigManager {
    config_path: AppPath,
}

impl ConfigManager {
    fn new(config_path: AppPath) -> Self {
        Self { config_path }
    }
}

Error Propagation Pattern

use app_path::{AppPath, AppPathError};

fn initialize_app() -> Result<(), Box<dyn std::error::Error>> {
    let config = AppPath::try_new("config.toml")?;
    let data = AppPath::try_new("data/app.db")?;
     
    // Initialize application with these paths
    println!("Config: {}", config.path().display());
    println!("Data: {}", data.path().display());
     
    Ok(())
}

pub fn path(&self) -> &Path

Get the full resolved path.

This is the primary method for getting the actual filesystem path where your file or directory is located.

Examples

use app_path::AppPath;

let config = AppPath::new("config.toml");

// Get the path for use with standard library functions
println!("Config path: {}", config.path().display());

// The path is always absolute
assert!(config.path().is_absolute());

pub fn exists(&self) -> bool

Check if the path exists.

Examples

use app_path::AppPath;

let config = AppPath::new("config.toml");

if config.exists() {
    println!("Config file found!");
} else {
    println!("Config file not found, using defaults.");
}

pub fn create_dir_all(&self) -> Result<()>

Create parent directories if they don’t exist.

This is equivalent to calling std::fs::create_dir_all on the parent directory of this path.

Examples

use app_path::AppPath;
use std::env;

// Use a temporary directory for the example
let temp_dir = env::temp_dir().join("app_path_example");
let data_file_path = temp_dir.join("data/users/profile.json");
let data_file = AppPath::new(data_file_path);

// Ensure the "data/users" directory exists
data_file.create_dir_all()?;

// Verify the directory was created
assert!(data_file.path().parent().unwrap().exists());

pub fn with_override( default: impl AsRef<Path>, override_option: Option<impl AsRef<Path>>, ) -> Self

Creates a path with override support (infallible).

This method provides a one-line solution for creating paths that can be overridden by external configuration. If an override is provided, it takes precedence over the default path. Otherwise, the default path is used with normal AppPath resolution.

This is the primary method for implementing configurable paths in applications. It combines the simplicity of AppPath::new() with the flexibility of external configuration overrides.

Common Use Cases

• Environment variable overrides: Allow users to customize file locations
• Command-line argument overrides: CLI tools with configurable paths

How It Works

If override is provided: Use the override path directly (can be relative or absolute) If override is None: Use the default path with normal AppPath resolution

Examples

use app_path::AppPath;
use std::env;

// Environment variable override
let config = AppPath::with_override(
    "config.toml",
    env::var("APP_CONFIG").ok()
);

// CLI argument override
fn get_config(cli_override: Option<&str>) -> AppPath {
    AppPath::with_override("config.toml", cli_override)
}

// Configuration file override
struct Config {
    data_dir: Option<String>,
}

let config = load_config();
let data_dir = AppPath::with_override("data", config.data_dir.as_deref());

pub fn with_override_fn<F, P>(default: impl AsRef<Path>, override_fn: F) -> Self

where F: FnOnce() -> Option<P>, P: AsRef<Path>,

Creates a path with dynamic override support.

Use this for complex override logic or lazy evaluation. The closure is called once to determine if an override should be applied.

Examples

use app_path::AppPath;
use std::env;

// Multiple fallback sources
let config = AppPath::with_override_fn("config.toml", || {
    env::var("APP_CONFIG").ok()
        .or_else(|| env::var("CONFIG_FILE").ok())
        .or_else(|| {
            // Only check expensive operations if needed
            if env::var("USE_SYSTEM_CONFIG").is_ok() {
                Some("/etc/myapp/config.toml".to_string())
            } else {
                None
            }
        })
});

// Development mode override
let data_dir = AppPath::with_override_fn("data", || {
    if env::var("DEVELOPMENT").is_ok() {
        Some("dev_data".to_string())
    } else {
        None
    }
});

pub fn try_with_override( default: impl AsRef<Path>, override_option: Option<impl AsRef<Path>>, ) -> Result<Self, AppPathError>

Creates a path with override support (fallible).

Fallible version of Self::with_override(). Most applications should use the infallible version instead for cleaner code.

Examples

use app_path::{AppPath, AppPathError};
use std::env;

fn get_config() -> Result<AppPath, AppPathError> {
    AppPath::try_with_override("config.toml", env::var("CONFIG").ok())
}

cleaner, more idiomatic code.

When to Use This Method

• Reusable libraries that should handle errors gracefully
• System-level tools that need to handle broken environments
• Applications with custom fallback strategies for rare edge cases

See AppPath::try_new() for detailed guidance on when to use fallible APIs.

Arguments

• default - The default path to use if no override is provided
• override_option - Optional override path that takes precedence if provided

Returns

• Ok(AppPath) - Successfully created AppPath with resolved path
• Err(AppPathError) - Failed to determine executable location

Examples

Library with Error Handling

use app_path::{AppPath, AppPathError};
use std::env;

fn create_config_path() -> Result<AppPath, AppPathError> {
    let config_override = env::var("MYAPP_CONFIG").ok();
    AppPath::try_with_override("config.toml", config_override.as_deref())
}

Error Propagation

use app_path::{AppPath, AppPathError};

fn setup_paths(config_override: Option<&str>) -> Result<(AppPath, AppPath), AppPathError> {
    let config = AppPath::try_with_override("config.toml", config_override)?;
    let data = AppPath::try_with_override("data", None::<&str>)?;
    Ok((config, data))
}

pub fn try_with_override_fn<F, P>( default: impl AsRef<Path>, override_fn: F, ) -> Result<Self, AppPathError>

where F: FnOnce() -> Option<P>, P: AsRef<Path>,

Creates a path with dynamic override support (fallible).

This is the fallible version of AppPath::with_override_fn(). Use this method when you need explicit error handling combined with dynamic override logic.

Most applications should use AppPath::with_override_fn() instead for cleaner, more idiomatic code.

When to Use This Method

• Reusable libraries with complex override logic that should handle errors gracefully
• System-level tools with dynamic configuration that need to handle broken environments
• Applications with custom fallback strategies for rare edge cases

See AppPath::try_new() for detailed guidance on when to use fallible APIs.

Arguments

• default - The default path to use if the override function returns None
• override_fn - A function that returns an optional override path

Returns

• Ok(AppPath) - Successfully created AppPath with resolved path
• Err(AppPathError) - Failed to determine executable location

Examples

Library with Complex Override Logic

use app_path::{AppPath, AppPathError};
use std::env;

fn create_data_path() -> Result<AppPath, AppPathError> {
    AppPath::try_with_override_fn("data", || {
        // Complex override logic with multiple sources
        env::var("DATA_DIR").ok()
            .or_else(|| env::var("MYAPP_DATA_DIR").ok())
            .or_else(|| {
                if env::var("DEVELOPMENT").is_ok() {
                    Some("dev_data".to_string())
                } else {
                    None
                }
            })
    })
}

Error Propagation with Dynamic Logic

use app_path::{AppPath, AppPathError};

fn setup_logging() -> Result<AppPath, AppPathError> {
    AppPath::try_with_override_fn("logs/app.log", || {
        // Dynamic override based on multiple conditions
        if std::env::var("SYSLOG").is_ok() {
            Some("/var/log/myapp.log".to_string())
        } else if std::env::var("LOG_TO_TEMP").is_ok() {
            Some(std::env::temp_dir().join("myapp.log").to_string_lossy().into_owned())
        } else {
            None
        }
    })
}

pub fn join(&self, path: impl AsRef<Path>) -> Self

Joins additional path segments to create a new AppPath.

This creates a new AppPath by joining the current path with additional segments. The new path inherits the same resolution behavior as the original.

Examples

use app_path::AppPath;

let data_dir = AppPath::new("data");
let users_db = data_dir.join("users.db");
let backups = data_dir.join("backups").join("daily");

// Chain operations for complex paths
let log_file = AppPath::new("logs")
    .join("2024")
    .join("app.log");

pub fn parent(&self) -> Option<Self>

Returns the parent directory as an AppPath, if it exists.

Returns None if this path is a root directory or has no parent.

Examples

use app_path::AppPath;    ///
let config = AppPath::new("config/app.toml");
let config_dir = config.parent().unwrap();

let logs_dir = AppPath::new("logs");
let _app_dir = logs_dir.parent(); // Points to exe directory

pub fn with_extension(&self, ext: &str) -> Self

Creates a new AppPath with the specified file extension.

If the path has an existing extension, it will be replaced. If no extension exists, the new extension will be added.

Examples

use app_path::AppPath;

let config = AppPath::new("config");
let config_toml = config.with_extension("toml");
let config_json = config.with_extension("json");

let log_file = AppPath::new("app.log");
let backup_file = log_file.with_extension("bak");

pub fn file_name(&self) -> Option<&OsStr>

Returns the file name of this path as an OsStr, if it exists.

This is a convenience method that delegates to the underlying Path.

Examples

use app_path::AppPath;

let config = AppPath::new("config/app.toml");
assert_eq!(config.file_name().unwrap(), "app.toml");

pub fn file_stem(&self) -> Option<&OsStr>

Returns the file stem of this path as an OsStr, if it exists.

This is a convenience method that delegates to the underlying Path.

Examples

use app_path::AppPath;

let config = AppPath::new("config/app.toml");
assert_eq!(config.file_stem().unwrap(), "app");

pub fn extension(&self) -> Option<&OsStr>

Returns the extension of this path as an OsStr, if it exists.

This is a convenience method that delegates to the underlying Path.

Examples

use app_path::AppPath;

let config = AppPath::new("config/app.toml");
assert_eq!(config.extension().unwrap(), "toml");

pub fn is_dir(&self) -> bool

Returns true if this path points to a directory.

This is a convenience method that delegates to the underlying Path.

Examples

use app_path::AppPath;

let data_dir = AppPath::new("data");
if data_dir.is_dir() {
    println!("Data directory exists");
}

pub fn is_file(&self) -> bool

Returns true if this path points to a regular file.

This is a convenience method that delegates to the underlying Path.

Examples

use app_path::AppPath;

let config = AppPath::new("config.toml");
if config.is_file() {
    println!("Config file exists");
}

Methods from Deref<Target = Path>

pub fn as_os_str(&self) -> &OsStr

Yields the underlying OsStr slice.

Examples

use std::path::Path;

let os_str = Path::new("foo.txt").as_os_str();
assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));

pub fn to_str(&self) -> Option<&str>

Yields a &str slice if the Path is valid unicode.

This conversion may entail doing a check for UTF-8 validity. Note that validation is performed because non-UTF-8 strings are perfectly valid for some OS.

Examples

use std::path::Path;

let path = Path::new("foo.txt");
assert_eq!(path.to_str(), Some("foo.txt"));

pub fn to_string_lossy(&self) -> Cow<'_, str>

Converts a Path to a Cow<str>.

Any non-UTF-8 sequences are replaced with U+FFFD REPLACEMENT CHARACTER.

Examples

Calling to_string_lossy on a Path with valid unicode:

use std::path::Path;

let path = Path::new("foo.txt");
assert_eq!(path.to_string_lossy(), "foo.txt");

Had path contained invalid unicode, the to_string_lossy call might have returned "fo�.txt".

pub fn to_path_buf(&self) -> PathBuf

Converts a Path to an owned PathBuf.

Examples

use std::path::{Path, PathBuf};

let path_buf = Path::new("foo.txt").to_path_buf();
assert_eq!(path_buf, PathBuf::from("foo.txt"));

pub fn is_absolute(&self) -> bool

Returns true if the Path is absolute, i.e., if it is independent of the current directory.

• On Unix, a path is absolute if it starts with the root, so is_absolute and has_root are equivalent.

• On Windows, a path is absolute if it has a prefix and starts with the root: c:\windows is absolute, while c:temp and \temp are not.

Examples

use std::path::Path;

assert!(!Path::new("foo.txt").is_absolute());

pub fn is_relative(&self) -> bool

Returns true if the Path is relative, i.e., not absolute.

See is_absolute’s documentation for more details.

Examples

use std::path::Path;

assert!(Path::new("foo.txt").is_relative());

pub fn has_root(&self) -> bool

Returns true if the Path has a root.

• On Unix, a path has a root if it begins with /.

• On Windows, a path has a root if it:

  • has no prefix and begins with a separator, e.g., \windows
  • has a prefix followed by a separator, e.g., c:\windows but not c:windows
  • has any non-disk prefix, e.g., \\server\share

Examples

use std::path::Path;

assert!(Path::new("/etc/passwd").has_root());

pub fn parent(&self) -> Option<&Path>

Returns the Path without its final component, if there is one.

This means it returns Some("") for relative paths with one component.

Returns None if the path terminates in a root or prefix, or if it’s the empty string.

Examples

use std::path::Path;

let path = Path::new("/foo/bar");
let parent = path.parent().unwrap();
assert_eq!(parent, Path::new("/foo"));

let grand_parent = parent.parent().unwrap();
assert_eq!(grand_parent, Path::new("/"));
assert_eq!(grand_parent.parent(), None);

let relative_path = Path::new("foo/bar");
let parent = relative_path.parent();
assert_eq!(parent, Some(Path::new("foo")));
let grand_parent = parent.and_then(Path::parent);
assert_eq!(grand_parent, Some(Path::new("")));
let great_grand_parent = grand_parent.and_then(Path::parent);
assert_eq!(great_grand_parent, None);

pub fn ancestors(&self) -> Ancestors<'_>

Produces an iterator over Path and its ancestors.

The iterator will yield the Path that is returned if the parent method is used zero or more times. If the parent method returns None, the iterator will do likewise. The iterator will always yield at least one value, namely Some(&self). Next it will yield &self.parent(), &self.parent().and_then(Path::parent) and so on.

Examples

use std::path::Path;

let mut ancestors = Path::new("/foo/bar").ancestors();
assert_eq!(ancestors.next(), Some(Path::new("/foo/bar")));
assert_eq!(ancestors.next(), Some(Path::new("/foo")));
assert_eq!(ancestors.next(), Some(Path::new("/")));
assert_eq!(ancestors.next(), None);

let mut ancestors = Path::new("../foo/bar").ancestors();
assert_eq!(ancestors.next(), Some(Path::new("../foo/bar")));
assert_eq!(ancestors.next(), Some(Path::new("../foo")));
assert_eq!(ancestors.next(), Some(Path::new("..")));
assert_eq!(ancestors.next(), Some(Path::new("")));
assert_eq!(ancestors.next(), None);

pub fn file_name(&self) -> Option<&OsStr>

Returns the final component of the Path, if there is one.

If the path is a normal file, this is the file name. If it’s the path of a directory, this is the directory name.

Returns None if the path terminates in ...

Examples

use std::path::Path;
use std::ffi::OsStr;

assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
assert_eq!(None, Path::new("foo.txt/..").file_name());
assert_eq!(None, Path::new("/").file_name());

pub fn strip_prefix<P>(&self, base: P) -> Result<&Path, StripPrefixError>

where P: AsRef<Path>,

Returns a path that, when joined onto base, yields self.

Errors

If base is not a prefix of self (i.e., starts_with returns false), returns Err.

Examples

use std::path::{Path, PathBuf};

let path = Path::new("/test/haha/foo.txt");

assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt")));
assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt")));
assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt")));
assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new("")));
assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new("")));

assert!(path.strip_prefix("test").is_err());
assert!(path.strip_prefix("/te").is_err());
assert!(path.strip_prefix("/haha").is_err());

let prefix = PathBuf::from("/test/");
assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt")));

pub fn starts_with<P>(&self, base: P) -> bool

where P: AsRef<Path>,

Determines whether base is a prefix of self.

Only considers whole path components to match.

Examples

use std::path::Path;

let path = Path::new("/etc/passwd");

assert!(path.starts_with("/etc"));
assert!(path.starts_with("/etc/"));
assert!(path.starts_with("/etc/passwd"));
assert!(path.starts_with("/etc/passwd/")); // extra slash is okay
assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay

assert!(!path.starts_with("/e"));
assert!(!path.starts_with("/etc/passwd.txt"));

assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo"));

pub fn ends_with<P>(&self, child: P) -> bool

where P: AsRef<Path>,

Determines whether child is a suffix of self.

Only considers whole path components to match.

Examples

use std::path::Path;

let path = Path::new("/etc/resolv.conf");

assert!(path.ends_with("resolv.conf"));
assert!(path.ends_with("etc/resolv.conf"));
assert!(path.ends_with("/etc/resolv.conf"));

assert!(!path.ends_with("/resolv.conf"));
assert!(!path.ends_with("conf")); // use .extension() instead

pub fn file_stem(&self) -> Option<&OsStr>

Extracts the stem (non-extension) portion of self.file_name.

The stem is:

• None, if there is no file name;
• The entire file name if there is no embedded .;
• The entire file name if the file name begins with . and has no other .s within;
• Otherwise, the portion of the file name before the final .

Examples

use std::path::Path;

assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap());
assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap());

See Also

This method is similar to Path::file_prefix, which extracts the portion of the file name before the first .

pub fn file_prefix(&self) -> Option<&OsStr>

🔬This is a nightly-only experimental API. (path_file_prefix)

Extracts the prefix of self.file_name.

The prefix is:

• None, if there is no file name;
• The entire file name if there is no embedded .;
• The portion of the file name before the first non-beginning .;
• The entire file name if the file name begins with . and has no other .s within;
• The portion of the file name before the second . if the file name begins with .

Examples

use std::path::Path;

assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap());
assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap());

See Also

This method is similar to Path::file_stem, which extracts the portion of the file name before the last .

pub fn extension(&self) -> Option<&OsStr>

Extracts the extension (without the leading dot) of self.file_name, if possible.

The extension is:

• None, if there is no file name;
• None, if there is no embedded .;
• None, if the file name begins with . and has no other .s within;
• Otherwise, the portion of the file name after the final .

Examples

use std::path::Path;

assert_eq!("rs", Path::new("foo.rs").extension().unwrap());
assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap());

pub fn join<P>(&self, path: P) -> PathBuf

where P: AsRef<Path>,

Creates an owned PathBuf with path adjoined to self.

If path is absolute, it replaces the current path.

See PathBuf::push for more details on what it means to adjoin a path.

Examples

use std::path::{Path, PathBuf};

assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd"));
assert_eq!(Path::new("/etc").join("/bin/sh"), PathBuf::from("/bin/sh"));

pub fn with_file_name<S>(&self, file_name: S) -> PathBuf

where S: AsRef<OsStr>,

Creates an owned PathBuf like self but with the given file name.

See PathBuf::set_file_name for more details.

Examples

use std::path::{Path, PathBuf};

let path = Path::new("/tmp/foo.png");
assert_eq!(path.with_file_name("bar"), PathBuf::from("/tmp/bar"));
assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt"));

let path = Path::new("/tmp");
assert_eq!(path.with_file_name("var"), PathBuf::from("/var"));

pub fn with_extension<S>(&self, extension: S) -> PathBuf

where S: AsRef<OsStr>,

Creates an owned PathBuf like self but with the given extension.

See PathBuf::set_extension for more details.

Examples

use std::path::Path;

let path = Path::new("foo.rs");
assert_eq!(path.with_extension("txt"), Path::new("foo.txt"));
assert_eq!(path.with_extension(""), Path::new("foo"));

Handling multiple extensions:

use std::path::Path;

let path = Path::new("foo.tar.gz");
assert_eq!(path.with_extension("xz"), Path::new("foo.tar.xz"));
assert_eq!(path.with_extension("").with_extension("txt"), Path::new("foo.txt"));

Adding an extension where one did not exist:

use std::path::Path;

let path = Path::new("foo");
assert_eq!(path.with_extension("rs"), Path::new("foo.rs"));

pub fn with_added_extension<S>(&self, extension: S) -> PathBuf

where S: AsRef<OsStr>,

🔬This is a nightly-only experimental API. (path_add_extension)

Creates an owned PathBuf like self but with the extension added.

See PathBuf::add_extension for more details.

Examples

#![feature(path_add_extension)]

use std::path::{Path, PathBuf};

let path = Path::new("foo.rs");
assert_eq!(path.with_added_extension("txt"), PathBuf::from("foo.rs.txt"));

let path = Path::new("foo.tar.gz");
assert_eq!(path.with_added_extension(""), PathBuf::from("foo.tar.gz"));
assert_eq!(path.with_added_extension("xz"), PathBuf::from("foo.tar.gz.xz"));
assert_eq!(path.with_added_extension("").with_added_extension("txt"), PathBuf::from("foo.tar.gz.txt"));

pub fn components(&self) -> Components<'_>

Produces an iterator over the Components of the path.

When parsing the path, there is a small amount of normalization:

• Repeated separators are ignored, so a/b and a//b both have a and b as components.

• Occurrences of . are normalized away, except if they are at the beginning of the path. For example, a/./b, a/b/, a/b/. and a/b all have a and b as components, but ./a/b starts with an additional CurDir component.

• A trailing slash is normalized away, /a/b and /a/b/ are equivalent.

Note that no other normalization takes place; in particular, a/c and a/b/../c are distinct, to account for the possibility that b is a symbolic link (so its parent isn’t a).

Examples

use std::path::{Path, Component};
use std::ffi::OsStr;

let mut components = Path::new("/tmp/foo.txt").components();

assert_eq!(components.next(), Some(Component::RootDir));
assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp"))));
assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt"))));
assert_eq!(components.next(), None)

pub fn iter(&self) -> Iter<'_>

Produces an iterator over the path’s components viewed as OsStr slices.

For more information about the particulars of how the path is separated into components, see components.

Examples

use std::path::{self, Path};
use std::ffi::OsStr;

let mut it = Path::new("/tmp/foo.txt").iter();
assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string())));
assert_eq!(it.next(), Some(OsStr::new("tmp")));
assert_eq!(it.next(), Some(OsStr::new("foo.txt")));
assert_eq!(it.next(), None)

pub fn display(&self) -> Display<'_>

Returns an object that implements Display for safely printing paths that may contain non-Unicode data. This may perform lossy conversion, depending on the platform. If you would like an implementation which escapes the path please use Debug instead.

Examples

use std::path::Path;

let path = Path::new("/tmp/foo.rs");

println!("{}", path.display());

pub fn metadata(&self) -> Result<Metadata, Error>

Queries the file system to get information about a file, directory, etc.

This function will traverse symbolic links to query information about the destination file.

This is an alias to fs::metadata.

Examples

use std::path::Path;

let path = Path::new("/Minas/tirith");
let metadata = path.metadata().expect("metadata call failed");
println!("{:?}", metadata.file_type());

pub fn symlink_metadata(&self) -> Result<Metadata, Error>

Queries the metadata about a file without following symlinks.

This is an alias to fs::symlink_metadata.

Examples

use std::path::Path;

let path = Path::new("/Minas/tirith");
let metadata = path.symlink_metadata().expect("symlink_metadata call failed");
println!("{:?}", metadata.file_type());

pub fn canonicalize(&self) -> Result<PathBuf, Error>

Returns the canonical, absolute form of the path with all intermediate components normalized and symbolic links resolved.

This is an alias to fs::canonicalize.

Examples

use std::path::{Path, PathBuf};

let path = Path::new("/foo/test/../test/bar.rs");
assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));

pub fn normalize_lexically(&self) -> Result<PathBuf, NormalizeError>

🔬This is a nightly-only experimental API. (normalize_lexically)

Normalize a path, including .. without traversing the filesystem.

Returns an error if normalization would leave leading .. components.

This function always resolves .. to the “lexical” parent. That is “a/b/../c” will always resolve to a/c which can change the meaning of the path. In particular, a/c and a/b/../c are distinct on many systems because b may be a symbolic link, so its parent isn’t a.

path::absolute is an alternative that preserves ... Or Path::canonicalize can be used to resolve any .. by querying the filesystem.

pub fn read_link(&self) -> Result<PathBuf, Error>

Reads a symbolic link, returning the file that the link points to.

This is an alias to fs::read_link.

Examples

use std::path::Path;

let path = Path::new("/laputa/sky_castle.rs");
let path_link = path.read_link().expect("read_link call failed");

pub fn read_dir(&self) -> Result<ReadDir, Error>

Returns an iterator over the entries within a directory.

The iterator will yield instances of io::Result<fs::DirEntry>. New errors may be encountered after an iterator is initially constructed.

This is an alias to fs::read_dir.

Examples

use std::path::Path;

let path = Path::new("/laputa");
for entry in path.read_dir().expect("read_dir call failed") {
    if let Ok(entry) = entry {
        println!("{:?}", entry.path());
    }
}

pub fn exists(&self) -> bool

Returns true if the path points at an existing entity.

Warning: this method may be error-prone, consider using try_exists() instead! It also has a risk of introducing time-of-check to time-of-use (TOCTOU) bugs.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

Examples

use std::path::Path;
assert!(!Path::new("does_not_exist.txt").exists());

See Also

This is a convenience function that coerces errors to false. If you want to check errors, call Path::try_exists.

pub fn try_exists(&self) -> Result<bool, Error>

Returns Ok(true) if the path points at an existing entity.

This function will traverse symbolic links to query information about the destination file. In case of broken symbolic links this will return Ok(false).

Path::exists() only checks whether or not a path was both found and readable. By contrast, try_exists will return Ok(true) or Ok(false), respectively, if the path was verified to exist or not exist. If its existence can neither be confirmed nor denied, it will propagate an Err(_) instead. This can be the case if e.g. listing permission is denied on one of the parent directories.

Note that while this avoids some pitfalls of the exists() method, it still can not prevent time-of-check to time-of-use (TOCTOU) bugs. You should only use it in scenarios where those bugs are not an issue.

This is an alias for std::fs::exists.

Examples

use std::path::Path;
assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt"));
assert!(Path::new("/root/secret_file.txt").try_exists().is_err());

pub fn is_file(&self) -> bool

Returns true if the path exists on disk and is pointing at a regular file.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

Examples

use std::path::Path;
assert_eq!(Path::new("./is_a_directory/").is_file(), false);
assert_eq!(Path::new("a_file.txt").is_file(), true);

See Also

This is a convenience function that coerces errors to false. If you want to check errors, call fs::metadata and handle its Result. Then call fs::Metadata::is_file if it was Ok.

When the goal is simply to read from (or write to) the source, the most reliable way to test the source can be read (or written to) is to open it. Only using is_file can break workflows like diff <( prog_a ) on a Unix-like system for example. See fs::File::open or fs::OpenOptions::open for more information.

pub fn is_dir(&self) -> bool

Returns true if the path exists on disk and is pointing at a directory.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

Examples

use std::path::Path;
assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
assert_eq!(Path::new("a_file.txt").is_dir(), false);

See Also

This is a convenience function that coerces errors to false. If you want to check errors, call fs::metadata and handle its Result. Then call fs::Metadata::is_dir if it was Ok.

pub fn is_symlink(&self) -> bool

Returns true if the path exists on disk and is pointing at a symbolic link.

This function will not traverse symbolic links. In case of a broken symbolic link this will also return true.

If you cannot access the directory containing the file, e.g., because of a permission error, this will return false.

Examples

use std::path::Path;
use std::os::unix::fs::symlink;

let link_path = Path::new("link");
symlink("/origin_does_not_exist/", link_path).unwrap();
assert_eq!(link_path.is_symlink(), true);
assert_eq!(link_path.exists(), false);

See Also

This is a convenience function that coerces errors to false. If you want to check errors, call fs::symlink_metadata and handle its Result. Then call fs::Metadata::is_symlink if it was Ok.

Trait Implementations

impl AsRef<OsStr> for AppPath

fn as_ref(&self) -> &OsStr

Converts AppPath to &OsStr for FFI operations.

This is useful when interfacing with operating system APIs that require OsStr.

Examples

use app_path::AppPath;
use std::ffi::OsStr;

let config = AppPath::new("config.toml");
let os_str: &OsStr = config.as_ref();

impl AsRef<Path> for AppPath

fn as_ref(&self) -> &Path

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<Path> for AppPath

fn borrow(&self) -> &Path

Allows AppPath to be borrowed as a Path.

This enables AppPath to be used seamlessly in collections that are keyed by Path, and allows for efficient lookups using &Path values.

Examples

use app_path::AppPath;
use std::collections::HashMap;
use std::path::Path;

let mut path_map = HashMap::new();
let app_path = AppPath::new("config.toml");
path_map.insert(app_path, "config data");

// Can look up using a &Path
let lookup_path = Path::new("relative/to/exe/config.toml");
// Note: This would only work if the paths actually match

impl Clone for AppPath

fn clone(&self) -> AppPath

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AppPath

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AppPath

fn default() -> Self

Creates an AppPath pointing to the executable’s directory.

This is equivalent to calling AppPath::new(""). The default instance represents the directory containing the executable, which is useful as a starting point for portable applications.

Examples

use app_path::AppPath;

let exe_dir = AppPath::default();
let empty_path = AppPath::new("");

// Default should be equivalent to new("")
assert_eq!(exe_dir, empty_path);

// Both should point to the executable directory
assert_eq!(exe_dir.path(), app_path::exe_dir());

impl Deref for AppPath

fn deref(&self) -> &Self::Target

Provides direct access to the underlying Path through deref coercion.

This allows AppPath to be used directly with any API that expects a &Path, making it a zero-cost abstraction in many contexts. All Path methods become directly available on AppPath instances.

Examples

use app_path::AppPath;

let app_path = AppPath::new("config.toml");

// Direct access to Path methods through deref
assert_eq!(app_path.extension(), Some("toml".as_ref()));
assert_eq!(app_path.file_name(), Some("config.toml".as_ref()));

// Works with functions expecting &Path
fn process_path(path: &std::path::Path) {
    println!("Processing: {}", path.display());
}

process_path(&app_path); // Automatic deref coercion

type Target = Path

The resulting type after dereferencing.

impl Display for AppPath

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&Path> for AppPath

fn from(path: &Path) -> Self

Converts to this type from the input type.

impl From<&PathBuf> for AppPath

fn from(path: &PathBuf) -> Self

Converts to this type from the input type.

impl From<&String> for AppPath

fn from(path: &String) -> Self

Converts to this type from the input type.

impl From<&str> for AppPath

fn from(path: &str) -> Self

Converts to this type from the input type.

impl From<AppPath> for OsString

fn from(app_path: AppPath) -> Self

Converts AppPath to OsString for owned FFI operations.

Examples

use app_path::AppPath;
use std::ffi::OsString;

let config = AppPath::new("config.toml");
let os_string: OsString = config.into();

impl From<AppPath> for PathBuf

fn from(app_path: AppPath) -> Self

Converts to this type from the input type.

impl From<PathBuf> for AppPath

fn from(path: PathBuf) -> Self

Converts to this type from the input type.

impl From<String> for AppPath

fn from(path: String) -> Self

Converts to this type from the input type.

impl Hash for AppPath

fn hash<H: Hasher>(&self, state: &mut H)

Computes a hash for the AppPath based on its resolved path.

This enables AppPath to be used as keys in hash-based collections like HashMap and HashSet. The hash is computed from the full resolved path, ensuring consistent behavior.

Examples

use app_path::AppPath;
use std::collections::HashMap;

let mut config_map = HashMap::new();
let config_path = AppPath::new("config.toml");
config_map.insert(config_path, "Configuration file");

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for AppPath

fn cmp(&self, other: &Self) -> Ordering

Compares two AppPath instances lexicographically based on their resolved paths.

This provides a total ordering that enables AppPath to be used in sorted collections like BTreeMap and BTreeSet.

Examples

use app_path::AppPath;
use std::collections::BTreeSet;

let mut paths = BTreeSet::new();
paths.insert(AppPath::new("config.toml"));
paths.insert(AppPath::new("data.db"));
paths.insert(AppPath::new("app.log"));

// Paths are automatically sorted lexicographically
let sorted: Vec<_> = paths.into_iter().collect();

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for AppPath

fn eq(&self, other: &Self) -> bool

Compares two AppPath instances for equality based on their resolved paths.

Two AppPath instances are considered equal if their full resolved paths are identical, regardless of how they were constructed.

Examples

use app_path::AppPath;

let path1 = AppPath::new("config.toml");
let path2 = AppPath::new("config.toml");
let path3 = AppPath::new("other.toml");

assert_eq!(path1, path2);
assert_ne!(path1, path3);

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for AppPath

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

Compares two AppPath instances lexicographically based on their resolved paths.

The comparison is performed on the full resolved paths, providing consistent ordering for sorting and collection operations.

Examples

use app_path::AppPath;

let path1 = AppPath::new("a.txt");
let path2 = AppPath::new("b.txt");

assert!(path1 < path2);

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for AppPath