add minigrep

minigrep/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "minigrep"
+version = "0.1.0"

minigrep/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "minigrep"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

minigrep/poem.txt

@@ -0,0 +1,16 @@
+I'm nobody! Who are you?
+我啥也不是，你呢？
+Are you nobody, too?
+牛逼如你也是无名之辈吗？
+Then there's a pair of us - don't tell!
+那我们就是天生一对，嘘！别说话！
+They'd banish us, you know.
+你知道，我们不属于这里。
+How dreary to be somebody!
+因为这里属于没劲的大人物！
+How public, like a frog
+他们就像青蛙一样呱噪，
+To tell your name the livelong day
+成天将自己的大名
+To an admiring bog!
+传遍整个无聊的沼泽！

minigrep/src/lib.rs

@@ -0,0 +1,103 @@
+use std::error::Error;
+use std::{env, fs};
+
+pub struct Config {
+    pub query: String,
+    pub file_path: String,
+    pub ignore_case: bool,
+}
+
+impl Config {
+    pub fn new(args: &[String]) -> Result<Config, &'static str> {
+        if args.len() < 3 {
+            return Err("not enough arguments");
+        }
+        let query = args[1].clone();
+        let file_path = args[2].clone();
+
+        let ignore_case = env::var("IGNORE_CASE").is_ok();
+
+        Ok(Config {
+            query,
+            file_path,
+            ignore_case,
+        })
+    }
+}
+
+pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(config.file_path)?;
+    let results = if config.ignore_case {
+        search_case_insensitive(&config.query, &contents)
+    } else {
+        search(&config.query, &contents)
+    };
+
+    for line in results {
+        println!("{line}");
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn one_result() {
+        let query = "duct";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
+    }
+
+    #[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_case_insensitive(query, contents)
+        );
+    }
+}
+
+pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let mut result = Vec::new();
+    for line in contents.lines() {
+        if line.contains(&query) {
+            result.push(line);
+        }
+    }
+    result
+}
+
+pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let query = query.to_lowercase();
+    let mut result = Vec::new();
+
+    for line in contents.lines() {
+        if line.to_lowercase().contains(&query) {
+            result.push(line);
+        }
+    }
+
+    result
+}

minigrep/src/main.rs

@@ -0,0 +1,20 @@
+use std::env;
+use std::process;
+
+use minigrep::Config;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let config = Config::new(&args).unwrap_or_else(|err| {
+        println!("Problem parsing arguments: {}", err);
+        process::exit(1);
+    });
+
+    println!("Searching for {}", config.query);
+    println!("In file {}", config.file_path);
+
+    if let Err(e) = minigrep::run(config) {
+        println!("Application error: {}", e);
+        process::exit(1);
+    }
+}