Merge pull request #631 from jbcrail/update-head

Update head.

Makefile

@@ -170,6 +170,7 @@ TEST_PROGS  := \
   false \
   fold \
   hashsum \
+  head \
   mkdir \
   mv \
   nl \

src/head/head.rs

@@ -25,13 +25,29 @@ mod util;
 static NAME: &'static str = "head";
 static VERSION: &'static str = "1.0.0";
 
+enum FilterMode {
+    Bytes(usize),
+    Lines(usize),
+}
+
+struct Settings {
+    mode: FilterMode,
+}
+
+impl Default for Settings {
+    fn default() -> Settings {
+        Settings {
+            mode: FilterMode::Lines(10),
+        }
+    }
+}
+
 pub fn uumain(args: Vec<String>) -> i32 {
-    let mut line_count = 10usize;
-    let mut byte_count = 0usize;
+    let mut settings: Settings = Default::default();
 
     // handle obsolete -number syntax
     let options = match obsolete(&args[1..]) {
-        (args, Some(n)) => { line_count = n; args },
+        (args, Some(n)) => { settings.mode = FilterMode::Lines(n); args },
         (args, None) => args
     };
 
@@ -41,8 +57,8 @@ pub fn uumain(args: Vec<String>) -> i32 {
 
     opts.optopt("c", "bytes", "Print the first K bytes.  With the leading '-', print all but the last K bytes", "[-]K");
     opts.optopt("n", "lines", "Print the first K lines.  With the leading '-', print all but the last K lines", "[-]K");
-    opts.optflag("h", "help", "help");
-    opts.optflag("V", "version", "version");
+    opts.optflag("h", "help", "display this help and exit");
+    opts.optflag("V", "version", "output version information and exit");
 
     let given_options = match opts.parse(&args) {
         Ok (m) => { m }
@@ -68,7 +84,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
                 return 1;
             }
             match n.parse::<usize>() {
-                Ok(m) => { line_count = m }
+                Ok(m) => { settings.mode = FilterMode::Lines(m) }
                 Err(e) => {
                     show_error!("invalid line count '{}': {}", n, e);
                     return 1;
@@ -77,7 +93,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
         }
         None => match given_options.opt_str("c") {
             Some(count) => match count.parse::<usize>() {
-                Ok(m) => byte_count = m,
+                Ok(m) => settings.mode = FilterMode::Bytes(m),
                 Err(e)=> {
                     show_error!("invalid byte count '{}': {}", count, e);
                     return 1;
@@ -89,16 +105,9 @@ pub fn uumain(args: Vec<String>) -> i32 {
 
     let files = given_options.free;
 
-    let count =
-        if use_bytes {
-            byte_count
-        } else {
-            line_count
-        };
-
     if files.is_empty() {
         let mut buffer = BufReader::new(stdin());
-        head(&mut buffer, count, use_bytes);
+        head(&mut buffer, &settings);
     } else {
         let mut multiple = false;
         let mut firstime = true;
@@ -117,7 +126,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
             let path = Path::new(file);
             let reader = File::open(&path).unwrap();
             let mut buffer = BufReader::new(reader);
-            if !head(&mut buffer, count, use_bytes) {
+            if !head(&mut buffer, &settings) {
                 break;
             }
         }
@@ -161,20 +170,23 @@ fn obsolete(options: &[String]) -> (Vec<String>, Option<usize>) {
 }
 
 // TODO: handle errors on read
-fn head<T: Read>(reader: &mut BufReader<T>, count: usize, use_bytes: bool) -> bool {
-    if use_bytes {
+fn head<T: Read>(reader: &mut BufReader<T>, settings: &Settings) -> bool {
+    match settings.mode {
+        FilterMode::Bytes(count) => {
             for byte in reader.bytes().take(count) {
                 if !pipe_print!("{}", byte.unwrap() as char) {
                     return false;
                 }
             }
-    } else {
+        },
+        FilterMode::Lines(count) => {
             for line in reader.lines().take(count) {
-            if !pipe_print!("{}", line.unwrap()) {
+                if !pipe_println!("{}", line.unwrap()) {
                     return false;
                 }
             }
         }
+    }
     true
 }
 

test/fixtures/head/lorem_ipsum.txt

@@ -0,0 +1,24 @@
+Lorem ipsum dolor sit amet,
+consectetur adipiscing elit.
+Nunc interdum suscipit sem vel ornare.
+Proin euismod,
+justo sed mollis dictum,
+eros urna ultricies augue,
+eu pharetra mi ex id ante.
+Duis convallis porttitor aliquam.
+Nunc vitae tincidunt ex.
+Suspendisse iaculis ligula ac diam consectetur lacinia.
+Donec vel velit dui.
+Etiam fringilla,
+dolor quis tempor vehicula,
+lacus turpis bibendum velit,
+et pellentesque elit odio a magna.
+Cras vulputate tortor non libero vehicula euismod.
+Aliquam tincidunt nisl eget enim cursus,
+viverra sagittis magna commodo.
+Cras rhoncus egestas leo nec blandit.
+Suspendisse potenti.
+Etiam ullamcorper leo vel lacus vestibulum,
+cursus semper eros efficitur.
+In hac habitasse platea dictumst.
+Phasellus scelerisque vehicula fringilla.

test/fixtures/head/lorem_ipsum_1_line.expected

@@ -0,0 +1 @@
+Lorem ipsum dolor sit amet,

test/fixtures/head/lorem_ipsum_5_chars.expected

@@ -0,0 +1 @@
+Lorem

test/fixtures/head/lorem_ipsum_default.expected

@@ -0,0 +1,10 @@
+Lorem ipsum dolor sit amet,
+consectetur adipiscing elit.
+Nunc interdum suscipit sem vel ornare.
+Proin euismod,
+justo sed mollis dictum,
+eros urna ultricies augue,
+eu pharetra mi ex id ante.
+Duis convallis porttitor aliquam.
+Nunc vitae tincidunt ex.
+Suspendisse iaculis ligula ac diam consectetur lacinia.

test/head.rs

@@ -0,0 +1,65 @@
+use std::process::Command;
+use util::*;
+
+static PROGNAME: &'static str = "./head";
+static INPUT: &'static str = "lorem_ipsum.txt";
+
+#[path = "common/util.rs"]
+#[macro_use]
+mod util;
+
+#[test]
+fn test_stdin_default() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd, get_file_contents(INPUT));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_default.expected"));
+}
+
+#[test]
+fn test_stdin_1_line_obsolete() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.args(&["-1"]), get_file_contents(INPUT));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_1_line.expected"));
+}
+
+#[test]
+fn test_stdin_1_line() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.args(&["-n", "1"]), get_file_contents(INPUT));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_1_line.expected"));
+}
+
+#[test]
+fn test_stdin_5_chars() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run_piped_stdin(&mut cmd.args(&["-c", "5"]), get_file_contents(INPUT));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_5_chars.expected"));
+}
+
+#[test]
+fn test_single_default() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run(&mut cmd.arg(INPUT));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_default.expected"));
+}
+
+#[test]
+fn test_single_1_line_obsolete() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run(&mut cmd.args(&["-1", INPUT]));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_1_line.expected"));
+}
+
+#[test]
+fn test_single_1_line() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run(&mut cmd.args(&["-n", "1", INPUT]));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_1_line.expected"));
+}
+
+#[test]
+fn test_single_5_chars() {
+    let mut cmd = Command::new(PROGNAME);
+    let result = run(&mut cmd.args(&["-c", "5", INPUT]));
+    assert_eq!(result.stdout, get_file_contents("lorem_ipsum_5_chars.expected"));
+}