Add collect_output function to shell commands

src/command.rs

@@ -4,11 +4,11 @@ use std::error::Error;
 use std::fmt::{Display, Formatter};
 use std::io;
 use std::iter::once;
-use std::process::{Command, ExitStatus, Stdio};
+use std::process::{Command, ExitStatus, Output};
 
 pub trait LogRunnable {
-  //TODO add function to query output on success, could further improve code readability
   fn run(&mut self, logger: &Logger) -> Result<(), SpecificExecutionError>;
+  fn collect_output(&mut self) -> Result<Output, SpecificExecutionError>;
 }
 
 impl LogRunnable for Command {
@@ -18,6 +18,13 @@ impl LogRunnable for Command {
       error,
     })
   }
+
+  fn collect_output(&mut self) -> Result<Output, SpecificExecutionError> {
+    collect_output(self, None).map_err(|error| SpecificExecutionError {
+      command: self,
+      error,
+    })
+  }
 }
 
 fn run(command: &mut Command, logger: &Logger) -> Result<(), ExecutionError> {
@@ -29,16 +36,26 @@ fn run(command: &mut Command, logger: &Logger) -> Result<(), ExecutionError> {
       }
     }
     LogLevel::Error => {
-      let output = command.stdout(Stdio::piped()).output()?;
-      if !output.status.success() {
-        log!(logger, error, "{}", String::from_utf8_lossy(&output.stderr));
-        Err(output.status)?;
-      }
+      collect_output(command, Some(logger))?;
     }
   }
   Ok(())
 }
 
+fn collect_output(
+  command: &mut Command,
+  logger: Option<&Logger>,
+) -> Result<Output, ExecutionError> {
+  let output = command.output()?; //pipes stdout and stderr automatically
+  if !output.status.success() {
+    if let Some(logger) = logger {
+      log!(logger, error, "{}", String::from_utf8_lossy(&output.stderr));
+    }
+    Err(output.status)?;
+  }
+  Ok(output)
+}
+
 #[derive(Debug)]
 pub struct SpecificExecutionError<'a> {
   pub command: &'a Command,