Add not builtin command - grep

src/grep.rs

@@ -0,0 +1,45 @@
+use std::env;
+use std::fs::{self, File};
+//use std::path::Path;
+//use std::io::BufReader;
+//use std::io::stdout;
+//use std::io::prelude::*;
+
+fn main(){
+    let args: Vec<String> = env::args().collect();
+    let mut pattern_and_filename: Vec<String> = Vec::new(); // 0 - pattern, 1 - name of files
+    
+    for arg in 1..args.len() {
+        match args[arg].as_str() {
+            "--help" => {
+                println!("Usage: grep [OPTIONS] FILE");
+                println!("Print lines matching a pattern");
+                return;
+            },
+            arg => {
+                if args.len() < 3 {
+                    println!("grep: Not enought arguments");
+                    return;
+                }      
+                pattern_and_filename.push(arg.to_string());
+            },
+        }
+    }
+    let pattern = &pattern_and_filename[0];
+    let filename = &pattern_and_filename[1];
+    let contents = fs::read_to_string(&filename);
+    //contents = "".to_string();
+    for line in search(pattern.to_string(), contents.unwrap().as_str()) {
+        println!("{}", line);
+    }
+}
+
+fn search<'a>(pattern: String, contents: &'a str) -> Vec<&'a str> {
+    let mut results = Vec::new();
+    for line in contents.lines() {
+        if line.contains(&pattern) {
+            results.push(line);
+        }
+    }
+    results
+}