Show HN: Runc – Compile and run C in one command

[koolba]

This looks fun. I can't imagine it being directly useful but the idea itself is fun.

Couple of immediate issues with the repo:

- Sample output in the README should not be prefixed with a "$". That's only for the shell command prompt.

- Use ``` blocks in your README file. It's easier to format multi-line text.

- Don't use $RANDOM, it's not secure. Use mktemp: https://github.com/alcover/runc/blob/73aaecea5a4cd357f7172dd...

- Don't exit with success if the command failed: https://github.com/alcover/runc/blob/73aaecea5a4cd357f7172dd...

- Use Bash strict mode: http://redsymbol.net/articles/unofficial-bash-strict-mode/

[tomjakubowski]

re: Bash "strict mode", the shell options are fine but resetting IFS blows the weirdness budget for a default.

You can get saner splitting for that loop over the array by quoting the array expansion:

    for name in "${names[@]}"

Shellcheck lints that, by the way.

[alcover]

Done, done and done. Thank you !

I need a little time to study your 'strict mode' suggestion. I used 'set -e' before but had problems with it.

Would you know how I could detect that input is cat'ed into the script ? ($ cat snippet.c | runc -i). So that I can suppress 'Type your code then CTRL+D'.

[brudgers]

This is not a complaint about the name. Just that as a command from the command line, "runc" may clash with the runc container running utility due to potential overlap in the likely users.

Again, it's not the project name just the potential clash at the OS level. Because over the years, I've done it to myself.

https://github.com/opencontainers/runc

[alcover]

Oh. Especially if one puts my script into ~/bin and calls '$ runc ..'

I admit I didn't research the name 'runc'.

Should I rename it ? I like this one because it's short and explicit.

[MaxBarraclough]

Neat. It wraps GCC.

See also Cling, an interactive C++ interpreter.

https://github.com/root-project/cling

[skolskoly]

Quick and ugly alternative is chmod+x and add something like this to the top of your file:

  //$(which gcc) $0 -o a.out; ./a.out $@; rm a.out; exit

[alcover]

Clever polyglot file!

Does not work in the spirit of my script though, since you would still need to add headers and main():

  //$(which gcc) $0 -o a.out; ./a.out $@; rm a.out; exit
  int i = 10;
  printf ("%d\n", i);

./snip.c:3:9: error: expected declaration specifiers or ‘...’ before string constant printf ("%d\n", i);

[solvorn]

This. My first thought was there is a UNIXy way to do this already.

[fish45]

This is definitely helpful for testing.

Also related is the tiny C compiler and its `tcc -run` command.

[jonathonf]

I was just about to reply about the same thing:

  #!/usr/bin/tcc -run
  
  #include <stdio.h>
  
  int main() {
    printf("Hello\n");
    return 0;
  }

[cozzyd]

why not call it rungcc, like the FSF t-shirt: https://shop.fsf.org/tshirts-hoodies/run-gcc-shirt

[crazypython]

D has the `rdmd` command for running D code in one command.

[gitgud]

Reminds me of [1] "c" a utility which allows you to execute C code as if it were a script. It's a shame the name is almost unsearchable in Google though...

[1] https://github.com/ryanmjacobs/c

[neilparikh]

I wrote something similar a few years ago: https://github.com/neilparikh/crepel

I wrote this for a hackathon, so please excuse the messy code :)

[skissane]

This idea has a lot of history behind it. The traditional term is “compile and go”.

https://en.m.wikipedia.org/wiki/Compile_and_go_system

[khrbtxyz]

I really like Tom Duff's http://www.iq0.com/duffgram/com.html to compile and run in two commands.

[zx2c4]

Another take on the same idea: https://git.zx2c4.com/cscript/about/

[glouwbug]

why not just do

    gcc main.c && ./a.out

[smabie]

That doesn't include the headers. It also leaves a.out on your system.

[verroq]

Why is this submission submitted a day ago showing up as new again? @dang