feat: add command function to return std::Command

Adds new `command` function that returns the underlying `std::Command`
that would be called to open given path.

Related: Byron#63
Related: helix-editor/helix#5820

src/haiku.rs

@@ -2,11 +2,14 @@ use std::{ffi::OsStr, io, process::Command};
 
 use crate::{CommandExt, IntoResult};
 
+pub fn command<T: AsRef<OsStr>>(path: T) -> Command {
+    let mut cmd = Command::new("/bin/open");
+    cmd.arg(path.as_ref());
+    cmd
+}
+
 pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
-    Command::new("/bin/open")
-        .arg(path.as_ref())
-        .status_without_output()
-        .into_result()
+    command(path).status_without_output().into_result()
 }
 
 pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {

src/ios.rs

@@ -2,12 +2,14 @@ use std::{ffi::OsStr, io, process::Command};
 
 use crate::{CommandExt, IntoResult};
 
+pub fn command<T: AsRef<OsStr>>(path: T) -> Command {
+    let mut cmd = Command::new("uiopen");
+    cmd.arg("--url").arg(path.as_ref());
+    cmd
+}
+
 pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
-    Command::new("uiopen")
-        .arg("--url")
-        .arg(path.as_ref())
-        .status_without_output()
-        .into_result()
+    command(path).status_without_output().into_result()
 }
 
 pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {

src/lib.rs

@@ -14,6 +14,12 @@
 //! open::with("http://rust-lang.org", "firefox").unwrap();
 //! ```
 //!
+//! Or obtain the command without running it.
+//!
+//! ```no_run
+//! let cmd = open::command("http://rust-lang.org");
+//! ```
+//!
 //! # Notes
 //!
 //! ## Nonblocking operation
@@ -131,6 +137,23 @@ pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()>
     os::with(path, app)
 }
 
+/// Get command that opens path with the default application.
+///
+/// # Examples
+///
+/// ```no_run
+/// let path = "http://rust-lang.org";
+/// let cmd = open::command(path);
+///
+/// match cmd.status_without_output().into_result() {
+///     Ok(()) => println!("Opened '{}' successfully.", path),
+///     Err(err) => panic!("An error occurred when opening '{}': {}", path, err),
+/// }
+/// ```
+pub fn command<'a, T: AsRef<OsStr>>(path: T) -> Command {
+    os::command(path)
+}
+
 /// Open path with the default application in a new thread.
 ///
 /// See documentation of [`that()`] for more details.

src/macos.rs

@@ -2,11 +2,14 @@ use std::{ffi::OsStr, io, process::Command};
 
 use crate::{CommandExt, IntoResult};
 
+pub fn command<T: AsRef<OsStr>>(path: T) -> Command {
+    let mut cmd = Command::new("/usr/bin/open");
+    cmd.arg(path.as_ref());
+    cmd
+}
+
 pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
-    Command::new("/usr/bin/open")
-        .arg(path.as_ref())
-        .status_without_output()
-        .into_result()
+    command(path).status_without_output().into_result()
 }
 
 pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {

src/unix.rs

@@ -8,39 +8,39 @@ use std::{
 
 use crate::{CommandExt, IntoResult};
 
-pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
+pub fn command<T: AsRef<OsStr>>(path: T) -> Command {
     let path = path.as_ref();
     let open_handlers = [
-        ("xdg-open", &[path] as &[_]),
-        ("gio", &[OsStr::new("open"), path]),
-        ("gnome-open", &[path]),
-        ("kde-open", &[path]),
-        ("wslview", &[&wsl_path(path)]),
+        ("xdg-open", &["--version"], &[path] as &[_]),
+        ("gio", &["version"], &[OsStr::new("open"), path]),
+        ("gnome-open", &["--version"], &[path]),
+        ("kde-open", &["--version"], &[path]),
+        ("wslview", &["--version"], &[&wsl_path(path)]),
     ];
 
-    let mut unsuccessful = None;
-    let mut io_error = None;
-
-    for (command, args) in &open_handlers {
-        let result = Command::new(command).args(*args).status_without_output();
+    for (command, check_args, args) in &open_handlers {
+        let result = Command::new(command)
+            .args(*check_args)
+            .status_without_output();
 
-        match result {
-            Ok(status) if status.success() => return Ok(()),
-            Ok(status) => {
-                unsuccessful = unsuccessful.or_else(|| {
-                    Some(std::io::Error::new(
-                        std::io::ErrorKind::Other,
-                        status.to_string(),
-                    ))
-                })
-            }
-            Err(err) => io_error = io_error.or(Some(err)),
-        }
+        if let Ok(status) = result {
+            if status.success() {
+                let mut cmd = Command::new(command);
+                cmd.args(*args);
+                return cmd;
+            };
+        };
     }
 
-    Err(unsuccessful
-        .or(io_error)
-        .expect("successful cases don't get here"))
+    // fallback to xdg-open
+    let (command, _, args) = &open_handlers[0];
+    let mut cmd = Command::new(command);
+    cmd.args(*args);
+    cmd
+}
+
+pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
+    command(path).status_without_output().into_result()
 }
 
 pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {