rwc

week2/rwc/src/main.rs

@@ -1,4 +1,7 @@
 use std::env;
+use std::cmp::max;
+use std::fs::File;
+use std::io::Read;
 use std::process;
 
 fn main() {
@@ -9,4 +12,47 @@ fn main() {
     }
     let filename = &args[1];
     // Your code here :)
+    let mut file =
+        File::open(filename).expect(format!("Cannot open file: {}\n", filename).as_str());
+    let mut buffer = [0; 1024];
+    let mut line_count = 0;
+    let mut word_count = 0;
+    let mut byte_count = 0;
+    let mut skip_ws = false;
+    let mut in_word = false;
+    loop {
+        let rd_size = file
+            .read(&mut buffer)
+            .expect(format!("Error reading file: {}", filename).as_str());
+        if rd_size == 0 {
+            break;
+        }
+        byte_count += rd_size;
+        for v in buffer {
+            if v == b'\n' {
+                line_count += 1;
+            }
+            if v.is_ascii_whitespace() {
+                if in_word && !skip_ws {
+                    skip_ws = true;
+                    in_word = false;
+                    word_count += 1;
+                }
+            } else {
+                in_word = true;
+                skip_ws = false;
+            }
+        }
+    }
+    let str_line_count = format!("{line_count}");
+    let str_word_count = format!("{word_count}");
+    let str_byte_count = format!("{byte_count}");
+    let align = max(
+        str_line_count.len(),
+        max(str_word_count.len(), str_byte_count.len()),
+    );
+    println!(
+        "{:>align$} {:>align$} {:>align$} {filename}",
+        str_line_count, str_word_count, str_byte_count
+    );
 }