uufuzz: add examples and them in the CI

fuzz/uufuzz/examples/simple_integration.rs

@@ -0,0 +1,105 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use std::ffi::OsString;
+use uufuzz::{CommandResult, run_gnu_cmd};
+
+fn main() {
+    println!("=== Simple Integration Testing uufuzz Example ===");
+    println!("This demonstrates how to use uufuzz to compare against GNU tools");
+    println!("without the complex file descriptor manipulation.\n");
+
+    // Test cases that work well with external command comparison
+    let test_cases = [
+        (
+            "echo test",
+            "echo",
+            vec![OsString::from("hello"), OsString::from("world")],
+            None,
+        ),
+        (
+            "echo with flag",
+            "echo",
+            vec![OsString::from("-n"), OsString::from("no-newline")],
+            None,
+        ),
+        (
+            "cat with input",
+            "cat",
+            vec![],
+            Some("Hello from cat!\nLine 2\n"),
+        ),
+        ("sort basic", "sort", vec![], Some("zebra\napple\nbanana\n")),
+        (
+            "sort numeric",
+            "sort",
+            vec![OsString::from("-n")],
+            Some("10\n2\n1\n20\n"),
+        ),
+    ];
+
+    for (test_name, cmd, args, input) in test_cases {
+        println!("--- {} ---", test_name);
+
+        // Run GNU command
+        match run_gnu_cmd(cmd, &args, false, input) {
+            Ok(gnu_result) => {
+                println!("✓ GNU {} succeeded", cmd);
+                println!(
+                    "  Stdout: {:?}",
+                    gnu_result.stdout.trim().replace('\n', "\\n")
+                );
+                println!("  Exit code: {}", gnu_result.exit_code);
+
+                // This demonstrates how you would compare results
+                // In real usage, you'd run your implementation and compare:
+                // let my_result = run_my_implementation(&args, input);
+                // assert_eq!(my_result.stdout, gnu_result.stdout);
+                // assert_eq!(my_result.exit_code, gnu_result.exit_code);
+            }
+            Err(error_result) => {
+                println!(
+                    "⚠ GNU {} failed or not available: {}",
+                    cmd, error_result.stderr
+                );
+                println!("  This is normal if GNU coreutils isn't installed");
+            }
+        }
+        println!();
+    }
+
+    println!("=== Practical Example: Compare two echo implementations ===");
+
+    // Simple echo comparison
+    let args = vec![OsString::from("hello"), OsString::from("world")];
+    match run_gnu_cmd("echo", &args, false, None) {
+        Ok(gnu_result) => {
+            println!("GNU echo result: {:?}", gnu_result.stdout.trim());
+
+            // Simulate our own echo implementation result
+            let our_result = CommandResult {
+                stdout: "hello world\n".to_string(),
+                stderr: String::new(),
+                exit_code: 0,
+            };
+
+            if our_result.stdout.trim() == gnu_result.stdout.trim()
+                && our_result.exit_code == gnu_result.exit_code
+            {
+                println!("✓ Our echo matches GNU echo!");
+            } else {
+                println!("✗ Our echo differs from GNU echo");
+                println!("  Our result: {:?}", our_result.stdout.trim());
+                println!("  GNU result: {:?}", gnu_result.stdout.trim());
+            }
+        }
+        Err(_) => {
+            println!("Cannot compare - GNU echo not available");
+        }
+    }
+
+    println!("\n=== Example completed ===");
+    println!("This approach is simpler and more reliable for integration testing.");
+}