Removed warnings in task2

hw7/task2/src/lib.rs

 extern crate nix;
 
 use std::io::{BufRead, Write};
-use std::str::{FromStr, Split};
+use std::str::FromStr;
 use std::env;
-use std::os::unix::io::RawFd;
 use std::ffi::{OsString, CString};
 use nix::unistd::ForkResult::{Child, Parent};
-use nix::sys::wait::{wait, waitpid, WaitStatus};
-use nix::unistd::{dup2, close, execvp, fork, pipe, read, write};
+use nix::sys::wait::wait;
+use nix::unistd::{dup2, close, execvp, fork, pipe};
 
 mod errortype;
 
             Command::Empty => {},
             Command::Program(cmd) => {
 
-                let mut commands = cmd.split('|');
+                let commands = cmd.split('|');
                 let commands_vec: Vec<&str> = commands.collect();
-                
-                let needs_pipe = commands_vec.len() == 2;
 
+                let needs_pipe = commands_vec.len() == 2;
 
 
                     let fi = fork();
                     match fi {
-                        Ok(Parent { child }) => {
-                            wait();
+                        Ok(Parent { child: _child }) => {
+                            let _ = wait();
 
                         }
                         Ok(Child) => {
                             if let Ok((reader, writer)) = pipe() {
                                 let sec = fork();
                                 match sec {
-                                    Ok(Parent { child }) => {
-                                        wait();
+                                    Ok(Parent { child: _child }) => {
+                                        let _ = wait();
                                         if let Some(second) = commands_vec.get(1) {
                                             match close(writer) {
                                                 Ok(_) => {},
     }
 
     fn execute(&self, cmd: &str){
-        let mut parts:Vec<&str> = cmd.split_whitespace().collect();
+        let parts:Vec<&str> = cmd.split_whitespace().collect();
         let args:Vec<CString> = parts.iter().map(|f| CString::new(*f).unwrap()).collect();
         let t = args.into_boxed_slice();