1use std::fs;
2use std::error::Error;
3use std::env;
4
5pub struct Config {
6 pub query: String,
7 pub filename: String,
8 pub case_sensitive: bool,
9}
10
11impl Config {
12 pub fn new(args: &[String]) -> Result<Config, &str> {
13 if args.len() < 3 {
14 return Err("not enough argument");
15 }
16 let query = args[1].clone();
17 let filename= args[2].clone();
18
19 let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
20 Ok(Config { query, filename, case_sensitive })
21 }
22}
23
24pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
25 let contents = fs::read_to_string(config.filename)?;
26
27 let result = if config.case_sensitive {
28 search(&config.query, &contents)
29 } else {
30 search_case_insensitive(&config.query, &contents)
31 };
32
33 for line in result {
34 println!("{}", line);
35 }
36
37 Ok(())
38}
39
40pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
41 let mut results = Vec::new();
42
43 for line in contents.lines() {
44 if line.contains(query) {
45 results.push(line);
46 }
47 }
48
49 results
50}
51
52pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
53 let query = query.to_lowercase();
54 let mut results = Vec::new();
55
56 for line in contents.lines() {
57 if line.to_lowercase().contains(&query) {
58 results.push(line);
59 }
60 }
61
62 results
63}
64
65#[cfg(test)]
66mod tests {
67 use super::*;
68
69 #[test]
70 fn case_sensitive() {
71 let query = "duct";
72 let contents = "\
73Rust:
74safe, fast, productive.
75Pick three.
76Duct tape.";
77
78 assert_eq!(vec!["safe, fast, productive."], search(query, contents));
79 }
80
81 #[test]
82 fn case_insensitive() {
83 let query = "rUsT";
84 let contents = "\
85Rust:
86safe, fast, productive.
87Pick three.
88Trust me.";
89
90 assert_eq!(
91 vec!["Rust:", "Trust me."],
92 search_case_insensitive(query, contents)
93 );
94 }
95}
96