File IO Exercises added and tested

exercises/24_file_io/README.md

@@ -0,0 +1,16 @@
+# File IO
+
+Rust Provides several file I/O functions in the standard library. Buffered reads and writes provides better performance by reducing underlying reads.
+
+## Further information
+
+Here is the documentation for these functions in the standard library.
+
+- [ReadToString](https://doc.rust-lang.org/std/fs/fn.read_to_string.html)
+- [BufReader](https://doc.rust-lang.org/std/io/struct.BufReader.html)
+- [BufWriter](https://doc.rust-lang.org/std/io/struct.BufWriter.html)
+- [Path](https://doc.rust-lang.org/stable/std/path/struct.Path.html)
+- [PathBuf](https://doc.rust-lang.org/std/path/struct.PathBuf.html)
+
+
+

exercises/24_file_io/SampleFilesFolder/MultiLineTextFile.txt

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+This is the first line of the text.
+This is the second line.
+And this is the third and the last line.

exercises/24_file_io/SampleFilesFolder/SampleTextFile.txt

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+This is the file content.

exercises/24_file_io/file_io1.rs

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+use std::fs;
+
+fn main() {
+
+    let read_str_result = fs::read_to_string("exercises/24_file_io/SampleFilesFolder/SampleTextFile.txt");
+
+    match read_str_result {
+        Ok(contents) => {
+            // TODO : What should the read string would be ?
+            let expected_string = 
+            assert_eq!(expected_string, contents);
+        }
+        Err(e) => {
+            eprintln!("Error reading file: {}", e);
+            assert!(false);
+        }
+    }
+}

exercises/24_file_io/file_io2.rs

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+
+use std::fs;
+use std::io::{BufRead, BufReader, BufWriter, Write};
+
+fn main() {
+
+    let input_file = fs::File::open("exercises/24_file_io/SampleFilesFolder/MultiLineTextFile.txt");
+
+    if input_file.is_err() {
+        eprintln!("Input file open error : {}", input_file.as_ref().unwrap_err());
+        assert!(false);
+    }
+
+    // TODO : How can we create a BufReader using input_file as parameter
+    let buffered_input_file = ;
+
+    let output_file = fs::File::create("MultiLineOutputFile.txt");
+
+    if output_file.is_err() {
+        eprintln!("Output file open error : {}", output_file.as_ref().unwrap_err());
+        assert!(false);
+    }
+    let mut buffered_file_writer = BufWriter::new(output_file.ok().unwrap());
+
+    let mut line_number = 1;
+    let mut lines = buffered_input_file.lines();
+    while let Some(line) = lines.next() {
+        if let Ok(line) = line {
+            let write_result = buffered_file_writer.write(format!("Line {} : {}\n", line_number, line).as_bytes());
+            if write_result.is_err() {
+                eprintln!("Write result error: {}", write_result.unwrap_err());
+                break;
+            }
+            line_number += 1;
+        }else {
+            eprintln!("Write line error : {}", line_number);
+            assert!(false);
+        }
+
+    }
+
+    println!("{} : lines processed", line_number - 1);
+}

exercises/24_file_io/file_io3.rs

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+use std::path::{Path, PathBuf};
+
+fn main() {
+
+    let mut path_buffer = PathBuf::new();
+
+    path_buffer.push("exercises");
+    path_buffer.push("24_file_io");
+    path_buffer.push("SampleFilesFolder");
+    path_buffer.push("MultiLineTextFile.txt");
+
+    // TODO : How we can get the metadata from path_buffer ?
+    let meta_data_result = path_buffer.
+
+    if let Ok(meta_data) = meta_data_result {
+        println!("Metadata about the file : {:?}", path_buffer);
+        println!("File creation time {:?}", meta_data.created().unwrap());
+        println!("File size {}", meta_data.len());
+        assert_eq!(meta_data.len(), 101);
+        println!("File permissions {:?}", meta_data.permissions());
+        assert_eq!(meta_data.permissions().readonly(), false);
+    }else {
+        println!("Could not get metadata");
+        assert!(false);
+    }
+
+
+
+
+}

rustlings-macros/info.toml

@@ -1200,3 +1200,26 @@ name = "as_ref_mut"
 dir = "23_conversions"
 hint = """
 Add `AsRef<str>` or `AsMut<u32>` as a trait bound to the functions."""
+
+# File IO Exercises
+
+[[exercises]]
+name = "file_io1"
+dir = "24_file_io"
+hint = """
+Basic File Reading
+"""
+
+[[exercises]]
+name = "file_io2"
+dir = "24_file_io"
+hint = """
+Buffered Reading & Writing
+"""
+
+[[exercises]]
+name = "file_io3"
+dir = "24_file_io"
+hint = """
+Path Manipulation & Metadata
+"""

solutions/24_file_io/SampleFilesFolder/MultiLineTextFile.txt

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+This is the first line of the text.
+This is the second line.
+And this is the third and the last line.

solutions/24_file_io/SampleFilesFolder/SampleTextFile.txt

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+This is the file content.

solutions/24_file_io/file_io1.rs

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+use std::fs;
+
+fn main() {
+
+    let read_str_result = fs::read_to_string("solutions/24_file_io/SampleFilesFolder/SampleTextFile.txt");
+
+    match read_str_result {
+        Ok(contents) => {
+            assert_eq!("This is the file content.", contents);
+        }
+        Err(e) => {
+            eprintln!("Error reading file: {}", e);
+            assert!(false);
+        }
+    }
+}

solutions/24_file_io/file_io2.rs

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+
+use std::fs;
+use std::io::{BufRead, BufReader, BufWriter, Write};
+
+fn main() {
+
+    let input_file = fs::File::open("solutions/24_file_io/SampleFilesFolder/MultiLineTextFile.txt");
+
+    if input_file.is_err() {
+        eprintln!("Input file open error : {}", input_file.as_ref().unwrap_err());
+        assert!(false);
+    }
+
+    let buffered_input_file = BufReader::new(input_file.unwrap());
+
+    let output_file = fs::File::create("MultiLineOutputFile.txt");
+
+    if output_file.is_err() {
+        eprintln!("Output file open error : {}", output_file.as_ref().unwrap_err());
+        assert!(false);
+    }
+    let mut buffered_file_writer = BufWriter::new(output_file.ok().unwrap());
+
+    let mut line_number = 1;
+    let mut lines = buffered_input_file.lines();
+    while let Some(line) = lines.next() {
+        if let Ok(line) = line {
+            let write_result = buffered_file_writer.write(format!("Line {} : {}\n", line_number, line).as_bytes());
+            if write_result.is_err() {
+                eprintln!("Write result error: {}", write_result.unwrap_err());
+                break;
+            }
+            line_number += 1;
+        }else {
+            eprintln!("Write line error : {}", line_number);
+            assert!(false);
+        }
+
+    }
+
+    println!("{} : lines processed", line_number - 1);
+}

solutions/24_file_io/file_io3.rs

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+use std::path::{Path, PathBuf};
+
+fn main() {
+
+    let mut path_buffer = PathBuf::new();
+
+    path_buffer.push("solutions");
+    path_buffer.push("24_file_io");
+    path_buffer.push("SampleFilesFolder");
+    path_buffer.push("MultiLineTextFile.txt");
+
+    let meta_data_result = path_buffer.metadata();
+
+    if let Ok(meta_data) = meta_data_result {
+        println!("Metadata about the file : {:?}", path_buffer);
+        println!("File creation time {:?}", meta_data.created().unwrap());
+        println!("File size {}", meta_data.len());
+        assert_eq!(meta_data.len(), 101);
+        println!("File permissions {:?}", meta_data.permissions());
+        assert_eq!(meta_data.permissions().readonly(), false);
+    }else {
+        println!("Could not get metadata");
+        assert!(false);
+    }
+
+
+
+
+}