提交命令管道实验

Author: dorname

exercises/01_concurrency_sync/04_process_pipe/src/lib.rs

@@ -49,11 +49,16 @@ use std::process::{Command, Stdio};
 /// 3. Call `.output()` to execute the child and obtain its `Output`.
 /// 4. Convert the `stdout` field (a `Vec<u8>`) into a `String`.
 pub fn run_command(program: &str, args: &[&str]) -> String {
-    // TODO: Use Command::new to create process
-    // TODO: Set stdout to Stdio::piped()
-    // TODO: Execute with .output() and get output
-    // TODO: Convert stdout to String and return
-    todo!()
+    // Use Command::new to create process
+    // Set stdout to Stdio::piped()
+    // Execute with .output() and get output
+    let cmd = Command::new(program).args(args).output().unwrap();
+    if !cmd.status.success() {
+        // Convert stdout to String and return
+        String::from_utf8_lossy(&cmd.stderr).to_string()
+    }else {
+        String::from_utf8_lossy(&cmd.stdout).to_string()
+    }
 }
 
 /// Write data to child process (cat) stdin via pipe and read its stdout output.
@@ -84,12 +89,19 @@ pub fn run_command(program: &str, args: &[&str]) -> String {
 /// 5. Read the child's stdout (`child.stdout.take().unwrap().read_to_string(...)`).
 /// 6. Wait for the child to exit with `.wait()` (or rely on drop‑wait).
 pub fn pipe_through_cat(input: &str) -> String {
-    // TODO: Create "cat" command, set stdin and stdout to piped
-    // TODO: Spawn process
-    // TODO: Write input to child process stdin
-    // TODO: Drop stdin to close pipe (otherwise cat won't exit)
-    // TODO: Read output from child process stdout
-    todo!()
+    // Create "cat" command, set stdin and stdout to piped
+    // 创建 cat 命令，并将标准输入（stdin）和标准输出（stdout）设置为管道模式
+    // Spawn process 启动（创建）子进程
+    // Write input to child process stdin 将输入数据写入子进程的标准输入（stdin）
+    // Drop stdin to close pipe (otherwise cat won't exit) 释放（drop）stdin 以关闭管道（否则 cat 不会退出）
+    // Read output from child process stdout 从子进程的标准输出（stdout）读取输出数据
+    let mut child = Command::new("cat").stdin(Stdio::piped()).stdout(Stdio::piped()).spawn().unwrap();
+    let mut stdin = child.stdin.unwrap();
+    stdin.write_all(input.as_bytes()).unwrap();
+    drop(stdin);
+    let mut buffer = String::new();
+    child.stdout.take().unwrap().read_to_string(&mut buffer).unwrap();
+    buffer
 }
 
 /// Get child process exit code.
@@ -107,10 +119,11 @@ pub fn pipe_through_cat(input: &str) -> String {
 /// 3. Use `.code()` to get the exit code as `Option<i32>`.
 /// 4. If the child terminated normally, return the exit code; otherwise return a default.
 pub fn get_exit_code(command: &str) -> i32 {
-    // TODO: Use Command::new("sh").args(["-c", command])
-    // TODO: Execute and get status
-    // TODO: Return exit code
-    todo!()
+    // Use Command::new("sh").args(["-c", command])
+    // Execute and get status
+    let status =  Command::new("sh").args(["-c", command]).status().unwrap();
+    // Return exit code
+    status.code().unwrap()
 }
 
 /// Execute the given shell command and return its stdout output as a `Result`.
@@ -133,11 +146,19 @@ pub fn get_exit_code(command: &str) -> i32 {
 /// 3. Call `.output()` and propagate any `io::Error`.
 /// 4. Convert `stdout` to `String` with `String::from_utf8`; if that fails, map to an `io::Error`.
 pub fn run_command_with_result(program: &str, args: &[&str]) -> io::Result<String> {
-    // TODO: Use Command::new to create process
-    // TODO: Set stdout to Stdio::piped()
-    // TODO: Execute with .output() and handle Result
-    // TODO: Convert stdout to String with from_utf8, mapping errors to io::Error
-    todo!()
+    // Use Command::new to create process
+    // Set stdout to Stdio::piped()
+    // Execute with .output() and handle Result
+    // Convert stdout to String with from_utf8, mapping errors to io::Error
+    let result = Command::new(program).args(args).stdout(Stdio::piped()).output();
+    if result.is_ok() {
+        let output = result.unwrap();
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        Ok(stdout.to_string())
+    }else {
+        Err(result.unwrap_err())
+    }
+
 }
 
 /// Interact with `grep` via bidirectional pipes, filtering lines that contain a pattern.
@@ -161,13 +182,34 @@ pub fn run_command_with_result(program: &str, args: &[&str]) -> io::Result<Strin
 /// 7. Return the concatenated matching lines as a single `String`.
 ///
 pub fn pipe_through_grep(pattern: &str, input: &str) -> String {
-    // TODO: Create "grep" command with pattern, set stdin and stdout to piped
-    // TODO: Spawn process
-    // TODO: Write input lines to child stdin
-    // TODO: Drop stdin to close pipe
-    // TODO: Read output from child stdout line by line
-    // TODO: Collect and return matching lines
-    todo!()
+    // Create "grep" command with pattern, set stdin and stdout to piped
+    // Spawn process
+    // Write input lines to child stdin
+    // Drop stdin to close pipe
+    // Read output from child stdout line by line
+    // Collect and return matching lines
+    let mut child = Command::new("grep")
+        .arg(pattern)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()
+        .unwrap();
+
+    let mut stdin = child.stdin.take().unwrap();
+    stdin.write_all(input.as_bytes()).unwrap();
+    drop(stdin);
+
+    let mut output = String::new();
+    child
+        .stdout
+        .take()
+        .unwrap()
+        .read_to_string(&mut output)
+        .unwrap();
+
+    child.wait().unwrap();
+
+    output
 }
 
 #[cfg(test)]