1use std::env;
2use std::error::Error;
3use std::fs;
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(mut args: std::env::Args) -> Result<Config, &'static str> {
13 args.next();
14
15 let query = match args.next() {
16 Some(arg) => arg,
17 None => return Err("Didn't get a query string"),
18 };
19
20 let filename = match args.next() {
21 Some(arg) => arg,
22 None => return Err("Didn't get a file name"),
23 };
24
25 let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
26
27 Ok(Config {
28 query,
29 filename,
30 case_sensitive,
31 })
32 }
33}
34
35pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
36 let contents = fs::read_to_string(config.filename)?;
37
38 let results = if config.case_sensitive {
39 search(&config.query, &contents)
40 } else {
41 search_case_insensitive(&config.query, &contents)
42 };
43
44 for line in results {
45 println!("{}", line);
46 }
47
48 Ok(())
49}
50
51pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
52 contents
53 .lines()
54 .filter(|line| line.contains(query))
55 .collect()
56}
57
58pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
59 contents
60 .lines()
61 .filter(|line| line.to_lowercase().contains(&query.to_lowercase()))
62 .collect()
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}