Command-line scripting with Rust. Wait, what?!

Transcript

2. @listochkin
4. @RustUkraine
5. Rust
6. Modern Language
7. Markdown for Comments
8. Build-in Unit testing
9. Tests for code in the docs
10. Package manager Cargo.toml Cargo.lock Multiple Versions
11. Learning by Doing
12. “System”
13. Drop-in replacement for C
14. Rust => .so / .dylib / .dll Node / Ruby / Python
15. Drivers Desktop Software Mobile Apps Servers IoT
16. Adoption: Project Infrastructure IDE / Editor integration CI / CD
17. Add a few lines to a Dockerfile?
18. One-off Scripts
19. Ad-hoc data processing
20. Troubleshooting
21. Custom metrics / healthchecks
22. Personal Workflows
23. Bash Perl Ruby / Python Node
24. find … | grep … | sed … | … > result.txt
25. ssh + netcat + custom UNIX sockets
26. Scripts for individual steps
27. /regex/
28. sed => perl
29. small “programs”
30. $EDITOR transform.lang chmod +x transform.lang ./transform.lang
31. Rust?!
32. cargo new omg-how-to-name-it cd omg-how-to-name-it cargo build ...
33. Many files A new repository
34. Not something temporary
35. Not scripting
36. cargo eval
37. cargo install cargo-eval $EDITOR hello.rs
38. #!/usr/bin/env cargo eval -- fn main() { println!("Hello world!"); }
39. chmod +x hello.rs ./hello.rs Hello world!
40. OMG!
41. Rust Scripting
43. Cargo Eval supports Cargo modules
44. #!/usr/bin/env cargo eval -- //! ```cargo //! [dependencies] //! time = "0.1.25" //! ``` extern crate time; fn main() { println!("{}", time::now().rfc822z()); }
45. #!/usr/bin/env cargo eval -- //! ```cargo //! [package] //! edition = "2018" //! [dependencies] //! time = "0.1.25" //! ``` fn main() { println!("{}", time::now().rfc822z()); }
46. #!/usr/bin/env cargo eval -- use std::io::*; fn main() -> Result<()> { for (n, line) in stdin().lock().lines().enumerate() { let line = line?; let line = line.trim_end(); if line.is_empty() { eprintln!("warning: empty line!"); } println!("{:>6}: {}", n, line.trim_end()) } Ok(()) }
47. Text Processing
48. str Strict UTF-8 not CESU-8 not Java Modified UTF-8
49. str ⇔ String OsStr ⇔ OsString Path ⇔ PathBuf CStr ⇔ CString
50. unicode_normalization unicode_segmentation
51. let s = "a\u{30a}"; assert_eq!(s.nfc().collect::<String>(), "å");
52. let s = "a̐éö̲\r\na\u{30a}"; let g: Vec<&str> = UnicodeSegmentation::graphemes(s, true) .collect(); let b = &["a̐", "é", "ö̲", "\r\n", "a\u{30a}"]; assert_eq!(g, b);
53. Case Folding
54. caseless
55. assert_eq!( canonical_caseless_match_str("Office", "office"), true); assert_eq!( canonical_caseless_match_str("straße", "Strasse"), true);
56. regex
57. Extended Syntax Unicode Named Capture Groups
58. No backreferences No conditionals No subroutines No recursion
59. Sad :(
60. lazy_static! { static ref RE: Regex = Regex::new( r"(?xu) #US date (?P<m> \d{2} ) # the month / (?P<d> \d{2} ) # the day / (?P<y> \d{4} ) # the year ", ) .unwrap(); } let before = "01/30/2018, 12/12/2019"; let after = RE.replace_all(before, "$y-$m-$d"); assert_eq!(after, "2018-01-30, 2019-12-12");
61. pcre2 ?
62. Running external commands
63. duct
64. use duct::cmd; cmd!( "osascript", "-e", "display notification \"Hello from Rust\" with title \"CLI\"" ) .run()?;
65. Ergonomics
66. quicli
67. create_dir remove_dir_all glob read_file write_to_file
68. CliResult logger CLI arguments Parallel Iterators
70. Drawbacks
71. So many crates!
72. Rust Regexes :/
73. Extra care is needed
74. What’s good?
75. rustfmt ./your-script.rs
76. Compiler helps
77. Doesn’t have to deal with Traits Borrow Checker
78. Compile most deps once
79. If you script often compilation time isn’t an issue
80. Rust Scripting is real
81. … | rust | …