fuzzing function should also return stderr

fuzz/fuzz_targets/fuzz_common.rs

@@ -3,10 +3,11 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-use libc::{close, dup, dup2, pipe, STDOUT_FILENO};
+use libc::{close, dup, dup2, pipe, STDERR_FILENO, STDOUT_FILENO};
 use std::ffi::OsString;
 use std::io;
 use std::io::Write;
+use std::os::fd::RawFd;
 use std::process::Command;
 use std::sync::atomic::Ordering;
 use std::sync::{atomic::AtomicBool, Once};
@@ -33,57 +34,90 @@ pub fn is_gnu_cmd(cmd_path: &str) -> Result<(), std::io::Error> {
     }
 }
 
-pub fn generate_and_run_uumain<F>(args: &[OsString], uumain_function: F) -> (String, i32)
+pub fn generate_and_run_uumain<F>(args: &[OsString], uumain_function: F) -> (String, String, i32)
 where
     F: FnOnce(std::vec::IntoIter<OsString>) -> i32,
 {
     let uumain_exit_status;
 
-    // Duplicate the stdout file descriptor
+    // Duplicate the stdout and stderr file descriptors
     let original_stdout_fd = unsafe { dup(STDOUT_FILENO) };
-    if original_stdout_fd == -1 {
-        return ("Failed to duplicate STDOUT_FILENO".to_string(), -1);
+    let original_stderr_fd = unsafe { dup(STDERR_FILENO) };
+    if original_stdout_fd == -1 || original_stderr_fd == -1 {
+        return (
+            "Failed to duplicate STDOUT_FILENO or STDERR_FILENO".to_string(),
+            "".to_string(),
+            -1,
+        );
     }
     println!("Running test {:?}", &args[0..]);
-    let mut pipe_fds = [-1; 2];
+    let mut pipe_stdout_fds = [-1; 2];
+    let mut pipe_stderr_fds = [-1; 2];
 
-    if unsafe { pipe(pipe_fds.as_mut_ptr()) } == -1 {
-        return ("Failed to create a pipe".to_string(), -1);
+    // Create pipes for stdout and stderr
+    if unsafe { pipe(pipe_stdout_fds.as_mut_ptr()) } == -1
+        || unsafe { pipe(pipe_stderr_fds.as_mut_ptr()) } == -1
+    {
+        return ("Failed to create pipes".to_string(), "".to_string(), -1);
     }
 
-    // Redirect stdout to the pipe
-    unsafe {
-        if dup2(pipe_fds[1], STDOUT_FILENO) == -1 {
-            close(pipe_fds[0]);
-            close(pipe_fds[1]);
-            return (
-                "Failed to redirect STDOUT_FILENO to the pipe".to_string(),
-                -1,
-            );
+    // Redirect stdout and stderr to their respective pipes
+    if unsafe { dup2(pipe_stdout_fds[1], STDOUT_FILENO) } == -1
+        || unsafe { dup2(pipe_stderr_fds[1], STDERR_FILENO) } == -1
+    {
+        unsafe {
+            close(pipe_stdout_fds[0]);
+            close(pipe_stdout_fds[1]);
+            close(pipe_stderr_fds[0]);
+            close(pipe_stderr_fds[1]);
         }
+        return (
+            "Failed to redirect STDOUT_FILENO or STDERR_FILENO".to_string(),
+            "".to_string(),
+            -1,
+        );
     }
 
     uumain_exit_status = uumain_function(args.to_owned().into_iter());
     io::stdout().flush().unwrap();
+    io::stderr().flush().unwrap();
 
-    // Restore the original stdout
-    unsafe {
-        if dup2(original_stdout_fd, STDOUT_FILENO) == -1 {
-            return (
-                "Failed to restore the original STDOUT_FILENO".to_string(),
-                -1,
-            );
-        }
-        close(original_stdout_fd);
+    // Restore the original stdout and stderr
+    if unsafe { dup2(original_stdout_fd, STDOUT_FILENO) } == -1
+        || unsafe { dup2(original_stderr_fd, STDERR_FILENO) } == -1
+    {
+        return (
+            "Failed to restore the original STDOUT_FILENO or STDERR_FILENO".to_string(),
+            "".to_string(),
+            -1,
+        );
     }
-    unsafe { close(pipe_fds[1]) };
+    unsafe {
+        close(original_stdout_fd);
+        close(original_stderr_fd);
+    }
+    unsafe { close(pipe_stdout_fds[1]) };
+    unsafe { close(pipe_stderr_fds[1]) };
 
+    let captured_stdout = read_from_fd(pipe_stdout_fds[0]).trim().to_string();
+    let captured_stderr = read_from_fd(pipe_stderr_fds[0]).to_string();
+    let captured_stderr = captured_stderr
+        .splitn(2, ':')
+        .nth(1)
+        .unwrap_or("")
+        .trim()
+        .to_string();
+
+    (captured_stdout, captured_stderr, uumain_exit_status)
+}
+
+fn read_from_fd(fd: RawFd) -> String {
     let mut captured_output = Vec::new();
     let mut read_buffer = [0; 1024];
     loop {
         let bytes_read = unsafe {
             libc::read(
-                pipe_fds[0],
+                fd,
                 read_buffer.as_mut_ptr() as *mut libc::c_void,
                 read_buffer.len(),
             )
@@ -93,29 +127,30 @@ where
             eprintln!("Failed to read from the pipe");
             break;
         }
-        if bytes_read <= 0 {
+        if bytes_read == 0 {
             break;
         }
         captured_output.extend_from_slice(&read_buffer[..bytes_read as usize]);
     }
 
-    unsafe { libc::close(pipe_fds[0]) };
+    unsafe { libc::close(fd) };
 
-    let my_output = String::from_utf8_lossy(&captured_output)
-        .to_string()
-        .trim()
-        .to_owned();
-
-    (my_output, uumain_exit_status)
+    String::from_utf8_lossy(&captured_output).into_owned()
 }
 
 pub fn run_gnu_cmd(
     cmd_path: &str,
     args: &[OsString],
     check_gnu: bool,
-) -> Result<(String, i32), io::Error> {
+) -> Result<(String, String, i32), (String, String, i32)> {
     if check_gnu {
-        is_gnu_cmd(cmd_path)?; // Check if it's a GNU implementation
+        match is_gnu_cmd(cmd_path) {
+            Ok(_) => {} // if the check passes, do nothing
+            Err(e) => {
+                // Convert the io::Error into the function's error type
+                return Err((String::new(), e.to_string(), -1));
+            }
+        }
     }
 
     let mut command = Command::new(cmd_path);
@@ -123,17 +158,25 @@ pub fn run_gnu_cmd(
         command.arg(arg);
     }
 
-    let output = command.output()?;
+    let output = match command.output() {
+        Ok(output) => output,
+        Err(e) => return Err((String::new(), e.to_string(), -1)),
+    };
     let exit_code = output.status.code().unwrap_or(-1);
+
+    // Here we get stdout and stderr as Strings
+    let stdout = String::from_utf8_lossy(&output.stdout).to_string();
+    let stderr = String::from_utf8_lossy(&output.stderr).to_string();
+    let stderr = stderr
+        .splitn(2, ':')
+        .nth(1)
+        .unwrap_or("")
+        .trim()
+        .to_string();
+
     if output.status.success() || !check_gnu {
-        Ok((
-            String::from_utf8_lossy(&output.stdout).to_string(),
-            exit_code,
-        ))
+        Ok((stdout, stderr, exit_code))
     } else {
-        Err(io::Error::new(
-            io::ErrorKind::Other,
-            format!("GNU command execution failed with exit code {}", exit_code),
-        ))
+        Err((stdout, stderr, exit_code))
     }
 }