Print messges to stdout int a way to make cargo test happy

Use `println!` to print messages to stdout, or `cargo test` would
not hide the output, see #23

Author: tao-guo

src/child.rs

@@ -1,7 +1,7 @@
 use crate::CmdResult;
 use log::info;
-use os_pipe::PipeReader;
-use std::io::{self, BufRead, BufReader, Error, ErrorKind, Read, Result, Write};
+use os_pipe::{self, PipeReader};
+use std::io::{BufRead, BufReader, Error, ErrorKind, Read, Result};
 use std::process::{Child, ExitStatus};
 use std::thread::JoinHandle;
 use CmdChild::{ProcChild, SyncChild, ThreadChild};
@@ -43,6 +43,12 @@ impl CmdChild {
                 cmd,
             } => {
                 Self::log_stderr_output(stderr);
+                if let Some(stdout) = child.stdout.take() {
+                    BufReader::new(stdout)
+                        .lines()
+                        .filter_map(|line| line.ok())
+                        .for_each(|line| println!("{}", line));
+                }
                 let status = child.wait()?;
                 if !status.success() && (is_last || pipefail) {
                     return Err(Self::status_to_io_error(
@@ -73,7 +79,7 @@ impl CmdChild {
                 if let Some(mut out) = output {
                     let mut buf = vec![];
                     check_result(out.read_to_end(&mut buf).map(|_| ()))?;
-                    check_result(io::stdout().write_all(&buf[..]))?;
+                    println!("{}", String::from_utf8_lossy(&buf));
                 }
             }
         }

src/process.rs

@@ -140,7 +140,7 @@ impl GroupCmds {
     pub fn spawn(mut self) -> Result<WaitCmd> {
         assert_eq!(self.group_cmds.len(), 1);
         let mut cmds = self.group_cmds.pop().unwrap().0;
-        let ret = cmds.spawn(&mut self.current_dir, false);
+        let ret = cmds.spawn(&mut self.current_dir);
         if let Err(ref err) = ret {
             error!("Spawning {} failed, Error: {}", cmds.get_full_cmds(), err);
         }
@@ -150,7 +150,7 @@ impl GroupCmds {
     pub fn spawn_with_output(mut self) -> Result<WaitFun> {
         assert_eq!(self.group_cmds.len(), 1);
         let mut cmds = self.group_cmds.pop().unwrap().0;
-        match cmds.spawn(&mut self.current_dir, true) {
+        match cmds.spawn(&mut self.current_dir) {
             Ok(ret) => Ok(WaitFun(ret.0)),
             Err(err) => {
                 error!("Spawning {} failed, Error: {}", cmds.get_full_cmds(), err);
@@ -181,7 +181,7 @@ impl Cmds {
         &self.full_cmds
     }
 
-    fn spawn(&mut self, current_dir: &mut String, with_output: bool) -> Result<WaitCmd> {
+    fn spawn(&mut self, current_dir: &mut String) -> Result<WaitCmd> {
         if std::env::var("CMD_LIB_DEBUG") == Ok("1".into()) {
             debug!("Running {} ...", self.get_full_cmds());
         }
@@ -200,19 +200,19 @@ impl Cmds {
             } else {
                 cmd.setup_redirects(&mut last_pipe_in, None)?;
             }
-            let child = cmd.spawn(current_dir, with_output)?;
+            let child = cmd.spawn(current_dir)?;
             children.push(child);
         }
 
         Ok(WaitCmd(children))
     }
 
     fn run_cmd(&mut self, current_dir: &mut String) -> CmdResult {
-        self.spawn(current_dir, false)?.wait_result_nolog()
+        self.spawn(current_dir)?.wait_result_nolog()
     }
 
     fn run_fun(&mut self, current_dir: &mut String) -> FunResult {
-        WaitFun(self.spawn(current_dir, true)?.0).wait_result_nolog()
+        WaitFun(self.spawn(current_dir)?.0).wait_result_nolog()
     }
 }
 
@@ -439,7 +439,7 @@ impl Cmd {
         }
     }
 
-    fn spawn(mut self, current_dir: &mut String, with_output: bool) -> Result<CmdChild> {
+    fn spawn(mut self, current_dir: &mut String) -> Result<CmdChild> {
         let arg0 = self.arg0();
         let full_cmd = self.debug_str();
         if arg0 == "cd" {
@@ -463,12 +463,10 @@ impl Cmd {
                 },
                 stdout: if let Some(redirect_out) = self.stdout_redirect.take() {
                     redirect_out
-                } else if with_output {
+                } else {
                     let (pipe_reader, pipe_writer) = os_pipe::pipe()?;
                     new_pipe_out = Some(pipe_reader);
                     CmdOut::CmdPipe(pipe_writer)
-                } else {
-                    CmdOut::CmdPipe(os_pipe::dup_stdout()?)
                 },
                 stderr: if let Some(redirect_err) = self.stderr_redirect.take() {
                     redirect_err
@@ -510,7 +508,7 @@ impl Cmd {
             // update stdout
             if let Some(redirect_out) = self.stdout_redirect.take() {
                 cmd.stdout(redirect_out);
-            } else if with_output {
+            } else {
                 cmd.stdout(Stdio::piped());
             }