Update custom command API signature

To allow spawning process with stdin/stdout redirection.

macros/src/lib.rs

@@ -44,8 +44,8 @@ pub fn main(
 /// ```
 /// # use cmd_lib::*;
 /// fn my_cmd(env: &mut CmdEnv) -> CmdResult {
-///     let msg = format!("msg from foo(), args: {:?}\n", env.args());
-///     writeln!(env.stderr(), "{}", msg)?;
+///     let msg = format!("msg from foo(), args: {:?}", env.get_args());
+///     writeln!(env.stderr(), "{msg}")?;
 ///     writeln!(env.stdout(), "bar")
 /// }
 ///

src/io.rs

@@ -29,6 +29,16 @@ impl From<CmdIn> for Stdio {
     }
 }
 
+impl CmdIn {
+    pub fn try_clone(&self) -> Result<Self> {
+        match self {
+            CmdIn::Null => Ok(CmdIn::Null),
+            CmdIn::File(file) => file.try_clone().map(CmdIn::File),
+            CmdIn::Pipe(pipe) => pipe.try_clone().map(CmdIn::Pipe),
+        }
+    }
+}
+
 pub enum CmdOut {
     Null,
     File(File),

src/lib.rs

@@ -377,6 +377,7 @@ pub type FunResult = std::io::Result<String>;
 /// Return type for [`run_cmd!()`] macro.
 pub type CmdResult = std::io::Result<()>;
 pub use child::{CmdChildren, FunChildren};
+pub use io::{CmdIn, CmdOut};
 #[doc(hidden)]
 pub use log as inner_log;
 #[doc(hidden)]

src/process.rs

@@ -10,7 +10,7 @@ use std::collections::HashMap;
 use std::ffi::{OsStr, OsString};
 use std::fmt;
 use std::fs::{File, OpenOptions};
-use std::io::{Error, ErrorKind, Read, Result, Write};
+use std::io::{Error, ErrorKind, Result};
 use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::sync::Mutex;
@@ -50,17 +50,17 @@ impl CmdEnv {
     }
 
     /// Returns a new handle to the standard input for this command.
-    pub fn stdin(&mut self) -> impl Read + '_ {
+    pub fn stdin(&mut self) -> &mut CmdIn {
         &mut self.stdin
     }
 
     /// Returns a new handle to the standard output for this command.
-    pub fn stdout(&mut self) -> impl Write + '_ {
+    pub fn stdout(&mut self) -> &mut CmdOut {
         &mut self.stdout
     }
 
     /// Returns a new handle to the standard error for this command.
-    pub fn stderr(&mut self) -> impl Write + '_ {
+    pub fn stderr(&mut self) -> &mut CmdOut {
         &mut self.stderr
     }
 }