Merge pull request #33 from k-nasa/replace_3_9_section

implement chapter3_9 other than problem 3_9_6

Author: yuk1ty

Cargo.lock

@@ -7,8 +7,25 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+rand = "0.8.3"
+zip = "0.5.12"
 lib = { path = "../lib" }
 
 [[bin]]
 name = "main_3_1"
 path = "src/3_1/main.rs"
+[[bin]]
+name = "3_9_1"
+path = "src/3_9_1/main.rs"
+[[bin]]
+name = "3_9_2"
+path = "src/3_9_2/main.rs"
+[[bin]]
+name = "3_9_3"
+path = "src/3_9_3/main.rs"
+[[bin]]
+name = "3_9_4"
+path = "src/3_9_4/main.rs"
+[[bin]]
+name = "3_9_5"
+path = "src/3_9_5/main.rs"

chapter3/Cargo.toml

@@ -0,0 +1,17 @@
+use std::env;
+use std::fs::File;
+use std::io;
+
+fn main() -> io::Result<()> {
+    let args: Vec<_> = env::args().collect();
+
+    let src = &args[1];
+    let dest = &args[2];
+
+    let mut file = File::open(src)?;
+    let mut new_file = File::create(dest)?;
+
+    io::copy(&mut file, &mut new_file)?;
+
+    Ok(())
+}

chapter3/src/3_9_1/main.rs

@@ -0,0 +1,14 @@
+use rand::Rng;
+use std::fs::File;
+use std::io;
+use std::io::Write;
+
+fn main() -> io::Result<()> {
+    let mut bytes = [0u8; 1024];
+    rand::thread_rng().fill(&mut bytes);
+
+    let mut file = File::create("random.txt")?;
+    file.write_all(&bytes)?;
+
+    Ok(())
+}

chapter3/src/3_9_2/main.rs

@@ -0,0 +1,13 @@
+use std::fs::File;
+use std::io;
+use std::io::Write;
+
+fn main() -> io::Result<()> {
+    let file = File::create("file.zip")?;
+
+    let mut zip = zip::ZipWriter::new(file);
+    zip.start_file("file.txt", zip::write::FileOptions::default())?;
+    zip.write_all(b"zipzipzipzipzipzipzipzipzipzipzipzipzipzipzipzip")?;
+
+    Ok(())
+}