src/bin/read_all.rs

@@ -17,7 +17,6 @@ fn main() {
 
     for line in reader.lines() {
         let line = line.unwrap();
-        println!("{}", line);
         println!("{}", User::new_from_string(&line).unwrap());
     }
 

src/group/mod.rs

@@ -7,6 +7,7 @@
 )]
 #![allow(clippy::non_ascii_literal)]
 
+use crate::userlib::NewFromString;
 use log::warn;
 use regex::Regex;
 
@@ -84,7 +85,7 @@ impl<'a> Display for Group<'a> {
     }
 }
 
-impl<'a> Group<'a> {
+impl<'a> NewFromString<'a> for Group<'a> {
     /// Parse a line formatted like one in `/etc/shadow` and construct a matching `Shadow` instance
     ///
     /// # Example
@@ -97,7 +98,7 @@ impl<'a> Group<'a> {
     ///
     /// # Errors
     /// When parsing fails this function returns a `UserLibError::Message` containing some information as to why the function failed.
-    pub fn new_from_string(line: &'a str) -> Result<Self, UserLibError> {
+    fn new_from_string(line: &'a str) -> Result<Self, UserLibError> {
         println!("{}", &line);
         let elements: Vec<&str> = line.split(':').collect();
         if elements.len() == 4 {

src/user/mod.rs

@@ -2,6 +2,7 @@ pub mod gecos_fields;
 pub mod passwd_fields;
 pub mod shadow_fields;
 
+use crate::userlib::NewFromString;
 use std::convert::TryFrom;
 use std::fmt::{self, Display};
 
@@ -18,7 +19,7 @@ pub struct User<'a> {
     shell_path: crate::ShellPath<'a>, /* Shell program.  */
 }
 
-impl<'a> User<'a> {
+impl<'a> NewFromString<'a> for User<'a> {
     /// Parse a line formatted like one in `/etc/passwd` and construct a matching [`adduser::User`] instance
     ///
     /// # Example
@@ -31,7 +32,10 @@ impl<'a> User<'a> {
     ///
     /// # Errors
     /// When parsing fails this function returns a `UserLibError::Message` containing some information as to why the function failed.
-    pub fn new_from_string(line: &'a str) -> Result<Self, crate::UserLibError> {
+    fn new_from_string(line: &'a str) -> Result<Self, crate::UserLibError>
+    where
+        Self: Sized,
+    {
         let elements: Vec<&str> = line.split(':').collect();
         if elements.len() == 7 {
             Ok(Self {
@@ -50,6 +54,9 @@ impl<'a> User<'a> {
             Err("Failed to parse: not enough elements".into())
         }
     }
+}
+
+impl<'a> User<'a> {
     #[must_use]
     pub const fn get_username(&self) -> &'a str {
         self.username.username

src/user/shadow_fields.rs

@@ -7,6 +7,7 @@
 )]
 #![allow(clippy::non_ascii_literal)]
 
+use crate::userlib::NewFromString;
 use log::warn;
 
 use crate::userlib_error::UserLibError;
@@ -77,7 +78,7 @@ fn show_option_duration(input: Option<chrono::Duration>) -> String {
     }
 }
 
-impl<'a> Shadow<'a> {
+impl<'a> NewFromString<'a> for Shadow<'a> {
     /// Parse a line formatted like one in `/etc/shadow` and construct a matching `Shadow` instance
     ///
     /// # Example
@@ -90,7 +91,7 @@ impl<'a> Shadow<'a> {
     ///
     /// # Errors
     /// When parsing fails this function returns a `UserLibError::Message` containing some information as to why the function failed.
-    pub fn new_from_string(line: &'a str) -> Result<Self, UserLibError> {
+    fn new_from_string(line: &'a str) -> Result<Self, UserLibError> {
         println!("{}", &line);
         let elements: Vec<&str> = line.split(':').collect();
         if elements.len() == 9 {

src/userlib.rs

@@ -8,13 +8,33 @@
 #![allow(clippy::non_ascii_literal)]
 
 use log::warn;
+use std::fs::File;
+use std::io::{BufReader, Read};
+use std::path::PathBuf;
 
 pub struct UserDBLocal<'a> {
+    source_files: Files,
     pub passwd_entries: Vec<crate::User<'a>>,
     pub shadow_entries: Vec<crate::Shadow<'a>>,
     pub group_entries: Vec<crate::Group<'a>>,
 }
 
+pub struct Files {
+    passwd: Option<PathBuf>,
+    shadow: Option<PathBuf>,
+    group: Option<PathBuf>,
+}
+
+impl Default for Files {
+    fn default() -> Self {
+        Self {
+            passwd: Some(PathBuf::from("/etc/passwd")),
+            shadow: Some(PathBuf::from("/etc/shadow")),
+            group: Some(PathBuf::from("/etc/group")),
+        }
+    }
+}
+
 impl<'a> UserDBLocal<'a> {
     #[must_use]
     pub fn import_from_strings(
@@ -23,6 +43,11 @@ impl<'a> UserDBLocal<'a> {
         group_content: &'a str,
     ) -> Self {
         let res = UserDBLocal {
+            source_files: Files {
+                passwd: None,
+                group: None,
+                shadow: None,
+            },
             passwd_entries: passwd_content
                 .lines()
                 .filter_map(|line| {
@@ -57,6 +82,53 @@ impl<'a> UserDBLocal<'a> {
         };
         res
     }
+
+    pub fn load_files(files: Files) -> Self {
+        let passwd_file =
+            File::open(files.group.expect("passwd file path cannot be None")).unwrap();
+        let mut passwd_reader = BufReader::new(passwd_file);
+        let mut my_passwd_lines = String::new();
+        passwd_reader.read_to_string(&mut my_passwd_lines).unwrap();
+        let group_file = File::open(files.group.expect("group file path cannot be None")).unwrap();
+        let mut group_reader = BufReader::new(group_file);
+        let mut my_group_lines = String::new();
+        group_reader.read_to_string(&mut my_group_lines).unwrap();
+        let shadow_file = File::open(files.shadow.expect("shadow file path cannot be None"))
+            .expect("Failed to read the shadow file. Most of the time root permissions are needed");
+        let mut shadow_reader = BufReader::new(group_file);
+        let mut my_shadow_lines = String::new();
+        shadow_reader.read_to_string(&mut my_shadow_lines).unwrap();
+
+        Self {
+            source_files: files,
+            passwd_entries: string_to(&my_passwd_lines),
+            group_entries: string_to(&my_group_lines),
+            shadow_entries: string_to(&my_shadow_lines),
+        }
+    }
+}
+
+pub trait NewFromString<'a> {
+    fn new_from_string(line: &'a str) -> Result<Self, crate::UserLibError>
+    where
+        Self: Sized;
+}
+
+fn string_to<'a, T>(source: &'a str) -> Vec<T>
+where
+    T: NewFromString<'a>,
+{
+    source
+        .lines()
+        .filter_map(|line| {
+            if line.len() > 5 {
+                println!("{}", line);
+                Some(T::new_from_string(line).expect("failed to read lines"))
+            } else {
+                None
+            }
+        })
+        .collect()
 }
 
 #[test]