In some programming languages, the "Hello, World!" tutorial programs report I/O errors in their exit status. In others, they silently swallow I/O errors, which doesn't satisfy common expectations of command-line programs.
Hello world programs are just toy examples. And, most languages do have ways to detect I/O errors on standard output. So, this page is effectively about defaults and ergonomics, in a specific context.
See also the original blog post for more discussion.
| Language | Notes | How to fix the bug |
|---|---|---|
| C | The C standard specifies this behavior | Example |
| C++ | The C++ standard specifies this behavior | |
| Crystal | Crystal 1.3.2 (2022-01-19) |
|
| Erlang/OTP | Before Erlang/OTP 26.0 | |
| Fortran | GNU Fortran 11.2.0 |
|
| Go | https://news.ycombinator.com/item?id=30612821 | |
| Haxe/HashLink | Haxe 4.2.4 + HashLink 1.11.0 |
|
| Haskell | The Glorious Glasgow Haskell Compilation System, version 8.8.4 |
|
| Java | This is documented behavior in Java, since Java 1.0 | |
| Julia | https://news.ycombinator.com/item?id=30619661 | |
| Lua | v5.3.3 |
Example |
| Nim | Nim Compiler Version 1.6.4 |
|
| Node.js | v12.21.0 |
|
| Pascal | https://news.ycombinator.com/item?id=30613381 | |
| Python 2 | Python 2.7.18 |
|
| Ruby | ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-linux-gnu] |
|
| Scheme | CHICKEN 5.2.0 |
|
| Swift | Swift version 5.5.3 |
| Language | Notes |
|---|---|
| Ada | GNAT 10.3.0 |
| Awk | GNU Awk 5.1.0, API: 3.0 (GNU MPFR 4.1.0, GNU MP 6.2.1) |
| Bash | GNU bash, version 5.1.4(1)-release (x86_64-pc-linux-gnu) |
| C# | Mono JIT compiler version 6.8.0.105 |
| Deno | deno 1.11.0 (release, x86_64-unknown-linux-gnu) |
| Erlang/OTP | Erlang/OTP 26.0 or above |
| Hack | HHVM 4.108 or above when using HSL IO |
| Hare | hare + harec 20230222 snapshot |
| Lisp | SBCL 2.1.1 |
| OCaml | 4.08.1 |
| Perl | perl 5, version 32, subversion 1 (v5.32.1) built for x86_64-linux-gnu-thread-multi (with 46 registered patches...) |
| Perl 6 | v2020.12 |
| Php | PHP 8.0.8 (cli) (build: Mar 3 2022 14:51:53) ( NTS ) |
| PowerShell | https://twitter.com/perostergaard/status/1501936409547993102 |
| Python 3 | Python 3.9.5 |
| Racket | Racket v7.9 [bc] |
| Rust | This is documented behavior in Rust. |
| Tcl | 8.6.11 |
| Zig | https://ziglang.org/documentation/master/#Hello-World |
The specific source code tested comes from doing simple Web searches for hello world programs. The intention is to test the programs that are presented to newcomers, and not programs specifically written to fix this bug.
In some cases, only a specific implementation has been tested, and it's not yet been determined what the actual documented or specified behavior is. In those cases, I've listed the versions tested, or links to reports.
Node.js (and Deno) is listed here as a "Language" because JavaScript itself doesn't have a builtin concept of standard output, so it takes an embedding like Node.js to connect JS features to command-line concepts such as standard output.
PRs adding more languages, more information about existing languages, updates, or corrections are welcome!
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