1use std::error::Error;
2use std::fs;
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, &'static str> {
13 if args.len() < 3 {
14 return Err("not enough arguments");
15 }
16 let query = args[1].clone();
17 let filename = args[2].clone();
18 let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
19
20 Ok(Config { query, filename, case_sensitive })
21 }
22}
23
24
25pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
26 let contents = fs::read_to_string(config.filename)?;
27
28 let results = if config.case_sensitive {
29 search(&config.query, &contents)
30 } else {
31 search_case_insensitive(&config.query, &contents)
32 };
33
34 for line in results {
35 println!("{}", line);
36 }
37
38 Ok(())
39}
40
41
42fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
43 let mut results = Vec::new();
44
45 for line in contents.lines() {
46 if line.contains(query) {
47 results.push(line);
48 }
49 }
50
51 results
52}
53
54fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
55 let query = query.to_lowercase();
56 let mut results = Vec::new();
57
58 for line in contents.lines() {
59 if line.to_lowercase().contains(&query) {
60 results.push(line);
61 }
62 }
63
64 results
65}
66
67#[cfg(test)]
68mod tests {
69 use super::*;
70
71 #[test]
72 fn case_sensitive() {
73 let query = "duct";
74 let contents = "\
75Rust:
76safe, fast, productive.
77Pick three.
78Duct tape.";
79
80 assert_eq!(
81 vec!["safe, fast, productive."],
82 search(query, contents)
83 );
84 }
85
86 #[test]
87 fn case_insensitive() {
88 let query = "rUsT";
89 let contents = "\
90Rust:
91safe, fast, productive.
92Pick three.
93Trust me.";
94
95 assert_eq!(
96 vec!["Rust:", "Trust me."],
97 search_case_insensitive(query, contents)
98 );
99 }
100}
101