uufuzz: add examples and them in the CI

fuzz/uufuzz/examples/pipe_input.rs

@@ -0,0 +1,68 @@
+// 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 std::io::{self, Read};
+use uufuzz::{compare_result, generate_and_run_uumain, run_gnu_cmd};
+
+// Mock cat implementation for demonstration
+fn mock_cat_main(args: std::vec::IntoIter<OsString>) -> i32 {
+    let _args: Vec<OsString> = args.collect();
+
+    // Read from stdin and write to stdout
+    let mut input = String::new();
+    match io::stdin().read_to_string(&mut input) {
+        Ok(_) => {
+            print!("{}", input);
+            0
+        }
+        Err(_) => {
+            eprintln!("Error reading from stdin");
+            1
+        }
+    }
+}
+
+fn main() {
+    println!("=== Pipe Input uufuzz Example ===");
+
+    let args = vec![OsString::from("cat")];
+    let pipe_input = "Hello from pipe!\nThis is line 2.\nAnd line 3.";
+
+    println!("Running mock cat implementation with pipe input...");
+    let rust_result = generate_and_run_uumain(&args, mock_cat_main, Some(pipe_input));
+
+    println!("Running GNU cat with pipe input...");
+    match run_gnu_cmd("cat", &args[1..], false, Some(pipe_input)) {
+        Ok(gnu_result) => {
+            println!("Comparing results...");
+            compare_result(
+                "cat",
+                "",
+                Some(pipe_input),
+                &rust_result,
+                &gnu_result,
+                false,
+            );
+        }
+        Err(error_result) => {
+            println!("Failed to run GNU cat: {}", error_result.stderr);
+            println!("This is expected if GNU coreutils is not installed");
+
+            // Show what our implementation produced
+            println!("\nOur implementation result:");
+            println!("Stdout: '{}'", rust_result.stdout);
+            println!("Stderr: '{}'", rust_result.stderr);
+            println!("Exit code: {}", rust_result.exit_code);
+
+            // Verify our mock implementation works
+            if rust_result.stdout.trim() == pipe_input.trim() {
+                println!("✓ Our mock cat implementation correctly echoed the pipe input");
+            } else {
+                println!("✗ Our mock cat implementation failed to echo the pipe input correctly");
+            }
+        }
+    }
+}