Exercises

Required Reading: Command-Line Rust

Recommended Reading:

1. Truth or Consequences

Objectives:

  • Getting Started with “Hello World”
  • Exercise Hello World
  • Code Organization in Rust
  • Creating and Running a Project with Cargo

  • Writing and Running Integration Tests

  • Creating our First Program “true” (https://man7.org/linux/man-pages/man1/true.1.html)

Linux Exit codes:

Exit code Meaning of the code
0 Command executed with no errors
1 Code for generic errors
2 Incorrect command (or argument) usage
126 Permission denied (or) unable to execute
127 Command not found, or PATH error
128+n Command terminated externally by passing signals, or it encountered a fatal error
130 Termination by Ctrl+C or SIGINT (termination code 2 or keyboard interrupt)
143 Termination by SIGTERM (default termination)
255/* Exit code exceeded the range 0-255, hence wrapped up

2. Test for Echo

Objectives:

  • Process command-line arguments with the clap crate
  • Use Rust types like strings, vectors, slices, and the unit type
  • Use expressions like match, if, and return
  • Use Option variants to represent Some value or None
  • Handle errors using the Result variants of Ok and Err
  • Understand the difference between stack and heap memory
  • Test for text that is printed to STDOUT and STDERR
  • Use Iterator::collect to turn an iterator into a vector
  • Create a struct

3. On the Catwalk

Objectives:

  • Use testing-first development
  • Test for the existence of a file
  • Create a random string for a filename that does not exist
  • Read regular files or STDIN (pronounced standard in )
  • Use eprintln! to print to STDERR and format! to format a string • Write a test that provides input on STDIN
  • Define mutually exclusive arguments
  • Use the enumerate method of an iterator

4. Head Aches

Objectives:

  • Create optional command-line arguments that accept numeric values
  • Convert between types using as
  • Use take on an iterator or a filehandle
  • Preserve line endings while reading a filehandle
  • Read bytes versus characters from a filehandle
  • Use the turbofish operator

5. Word to Your Mother

Objectives:

  • Use the Iterator::all function
  • Create a module for unit tests
  • Fake a filehandle for testing
  • Conditionally format and print a value
  • Conditionally compile a module when testing
  • Break a line of text into words, bytes, and characters

6. Den of Uniquity

Objectives:

  • Write to a file or STDOUT
  • Use a closure to capture a variable
  • Apply the don’t repeat yourself (DRY) concept
  • Use the Write trait and the write! and writeln!
  • Use temporary files
  • Indicate the lifetime of a variable macros

7. Finders Keepers

Objectives:

  • Use clap to constrain possible values for command-line arguments
  • Use a regular expression to find a pattern of text
  • Create an enumerated type with an implementation
  • Recursively search filepaths using the walkdir crate
  • Use the Iterator::any function
  • Chain multiple filter, map ,and filter_map operations
  • Compile code conditionally when on Windows or not
  • Refactor code

8. Shave and a Haircut

Objectives:

  • Read and write a delimited text file using the
  • Deference a value using *
  • Use Iterator::flatten
  • Use Iterator::flat_map csv crate to remove nested structures from iterators to combine Iterator::map and Iterator::flatten

9. Jack the Grepper

Objectives:

  • Using a case-sensitive regular expression
  • Variations of regular expression syntax
  • Another syntax to indicate a trait bound
  • Using Rust’s bitwise exclusive-OR operator

10. Boston Commons

Objectives:

  • Manually iterate the lines of a filehandle using
  • match on combinations of possibilities using a tuple
  • Use std::cmp::Ordering when comparing strings Iterator::next

11. Tailor Swyfte

Objectives:

  • Initialize a static, global, computed value
  • Seek to a line or byte position in a filehandle
  • Indicate multiple trait bounds on a type using the where
  • Build a release binary with Cargo
  • Benchmark programs to compare runtime performance clause

12. Fortunate Son

Objectives:

  • Use the Path and PathBuf structs to represent system paths
  • Parse records of text spanning multiple lines from a file
  • Use randomness and control it with seeds
  • Use the OsStr and OsString types to represent filenames
  • (Optional): Basic async processing using Tokio (https://tokio.rs/tokio/tutorial)

13. Rascalry

Objectives:

  • Find today’s date and do basic date manipulations
  • Use Vec::chunks to create groupings of items
  • Combine elements from multiple iterators
  • Produce highlighted text in the terminal

14. Elless Island

Objectives:

  • Find today’s date and do basic date manipulations
  • Use Vec::chunks to create groupings of items
  • Combine elements from multiple iterators
  • Produce highlighted text in the terminal