v0.1.4: use stderr for error messages

src/lib.rs

@@ -1,3 +1,100 @@
-pub fn run() {
-    println!("hello")
+use std::fs;
+//use std::fs::File;
+//use std::io::prelude::*;
+use std::error::Error;
+use std::env;
+
+pub struct Config {
+    query: String,
+    filename: String,
+    insensitive: bool,
+}
+
+pub fn run(conf: Config) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(conf.filename)?;
+
+    let results = if conf.insensitive {
+        search(&conf.query, &contents)
+    } else {
+        search_insensitive(&conf.query, &contents)
+    };
+
+    for line in results {
+        println!("{}", line);
+    }
+
+    Ok(())
+}
+
+fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let mut results = Vec::new();
+
+    for line in contents.lines() {
+        if line.contains(query) {
+          results.push(line);
+        }
+    }
+
+    results
+}
+
+fn search_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let query = query.to_lowercase();
+    let mut results = Vec::new();
+
+    for line in contents.lines() {
+        if line.to_lowercase().contains(&query) {
+          results.push(line);
+        }
+    }
+
+    results
+}
+
+impl Config {
+    pub fn new(args: &[String]) -> Result<Config, &'static str> {
+        if args.len() < 3 {
+            return Err("too few arguments")
+        }
+
+        Ok(Config {
+            query: args[1].clone(),
+            filename: args[2].clone(),
+            insensitive: env::var("CASE_INSENSITIVE").is_err(),
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn case_sensitive() {
+        let query = "duct";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(
+            vec!["safe, fast, productive."],
+            search(query, contents)
+        );
+    }
+
+    #[test]
+    fn case_insensitive() {
+        let query = "rUsT";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.
+Trust me.";
+
+        assert_eq!(
+            vec!["Rust:", "Trust me."],
+            search_insensitive(query, contents)
+        );
+    }
 }

src/main.rs

@@ -1,38 +1,22 @@
 extern crate grep;
 
 use std::env;
-use std::fs::File;
-use std::io::prelude::*;
-
-struct Config {
-    query: String,
-    filename: String,
-}
+use std::process;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
 
-    let conf = parse_config(&args);
+    let conf = grep::Config::new(&args).unwrap_or_else(|err| {
+        eprintln!("Problem parsing arguments: {}", err);
+        process::exit(1);
+    });
+    //let filename = &conf.filename.clone();
 
-    println!("{:?} {:?}", conf.query, conf.filename);
+    if let Err(e) = grep::run(conf) {
+        eprintln!("Big bad bada boom!\n{:?}", e);
+        //println!("Big bad bada boom!\n{:?}", e.kind());
+        //println!("Big bad bada boom!\n{}", e.description());
 
-    let mut f = File::open(&conf.filename).expect(&("file not found: ".to_owned() + &conf.filename));
-    //let mut f = File::open(filename).expect(&format!("file not found: {}", &filename));
-
-    let mut contents = String::new();
-    f.read_to_string(&mut contents)
-        .expect("something went wrong reading the file");
-
-    println!("Searching for '{}'", conf.query);
-    println!("In file '{}'", conf.filename);
-    println!("With text:\n{}", contents);
-}
-
-//fn parse_config(args: &[String]) -> (&String, &String)
-//fn parse_config(args: &[String]) -> (&str, &str)
-fn parse_config(args: &[String]) -> Config {
-    Config {
-        query: args[1].clone(),
-        filename: args[2].clone(),
+        process::exit(1);
     }
 }