Add stdin support to wc

Author: morr0ne

docs/wc.txt

@@ -9,3 +9,5 @@ or end of input.
   -w, --words    print the word counts
       --help     display this help and exit
       --version  output version information and exit
+
+With no FILE, or when FILE is -, read standard input.

src/bin/wc.rs

@@ -1,6 +1,6 @@
 use std::{
     fs::File,
-    io::{BufRead, BufReader, BufWriter, Write, stdout},
+    io::{BufRead, BufReader, BufWriter, Write, stdin, stdout},
 };
 
 use puppyutils::{Result, cli};
@@ -14,6 +14,30 @@ bitflags::bitflags! {
     }
 }
 
+fn count_lines<R: BufRead>(mut reader: R) -> Result<(usize, usize, usize, usize)> {
+    let mut lines = 0usize;
+    let mut words = 0usize;
+    let mut chars = 0usize;
+    let mut bytes = 0usize;
+    let mut line = String::new();
+
+    loop {
+        let read_bytes = reader.read_line(&mut line)?;
+        
+        if read_bytes == 0 {
+            break;
+        }
+
+        bytes += read_bytes;
+        lines += 1;
+        words += line.split_whitespace().count();
+        chars += line.chars().count();
+        line.clear();
+    }
+
+    Ok((lines, words, chars, bytes))
+}
+
 pub fn main() -> Result {
     let mut stdout = stdout();
     let mut files = Vec::new();
@@ -31,46 +55,25 @@ pub fn main() -> Result {
         }
     };
 
-    #[allow(unused)]
     if flags.is_empty() {
         flags = Flags::LINES | Flags::WORDS | Flags::BYTES;
     }
 
     let mut stdout = BufWriter::new(stdout);
 
-    for path in files {
-        let file = File::open(&path)?;
-
-        let mut bytes = file.metadata().map(|m| m.len()).unwrap_or(0) as usize;
-
-        let mut lines = 0usize;
-        let mut words = 0usize;
-        let mut chars = 0usize;
-
-        let mut reader = BufReader::new(file);
-
-        let mut line = String::new();
-
-        loop {
-            let read_bytes = reader.read_line(&mut line)?;
-
-            if read_bytes == 0 {
-                break;
-            }
-
-            if bytes == 0 {
-                bytes += read_bytes;
-            }
-
-            lines += 1;
-            words += line.split_whitespace().count();
-            chars += line.chars().count();
+    // If no files, read from stdin
+    if files.is_empty() {
+        files.push("-".to_string());
+    }
 
-            line.clear();
-        }
+    for path in files {
+        let (lines, words, chars, bytes) = if path == "-" {
+            count_lines(BufReader::new(stdin()))?
+        } else {
+            count_lines(BufReader::new(File::open(&path)?))?
+        };
 
         let mut first = true;
-
         let mut write_num = |num: usize| -> Result<()> {
             if !first {
                 stdout.write_all(b" ")?;
@@ -96,19 +99,13 @@ pub fn main() -> Result {
             write_num(bytes)?;
         }
 
-        stdout.write_all(b" ")?;
-        stdout.write_all(path.as_bytes())?;
+        if path != "-" {
+            stdout.write_all(b" ")?;
+            stdout.write_all(path.as_bytes())?;
+        }
+
         stdout.write_all(b"\n")?;
     }
 
     Ok(())
 }
-
-fn _count_padding(mut n: usize) -> usize {
-    let mut count = 0;
-    while n % 10 == 0 {
-        n /= 10;
-        count += 1;
-    }
-    count
-}