Update Omake for Linux running

[chuggafan]

This is a prototype with some basic changes for linux, this DOES NOT CURRENTLY WORK, and I know this because I haven't tested anything to do with actually capturing process output, this is just some fill-in from before to get some eyeballs on this.

The main thing stopping me from getting anywhere is my complete inability to understand how the dup2 stuff works, and all of the pipe issues, which gets me lost immediately upon trying to understand it, I'm at the point of trying to understand how glibc implements popen and it has also gotten me absolutely nowhere...
@GitMensch I assume you have the best eyes to know what in the universe POSIX is supposed to be doing and if I'm on the right track here, because I sure know I don't.

[chuggafan]

Ok, so I've done some testing, I've figured out how to get the readout from posix_spawn properly, thankfully, it's not too bad, it's just annoying because I have to juggle multiple pipes (for stdout and stdin) on that, and then remember everything, I've actually made a test-program for this because the online documentation is so bad that it's not understandable to a beginning that I'll add here in case someone in the future somehow finds this and wants my work as a reference:

#define _GNU_SOURCE
#include <spawn.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <poll.h>
extern char **environ;
int main()
{
    posix_spawn_file_actions_t spawn_actions;
    posix_spawnattr_t attrs;
    posix_spawn_file_actions_init(&spawn_actions);
    posix_spawnattr_init(&attrs);
    pid_t spawned_pid;
    int pipes[2];
    int ret = pipe2(pipes, O_CLOEXEC);
    if (ret != 0)
    {
        printf("Pipe failed\n");
    }
    // Copy stdout to the writable pipe, pipes[0] is the readable pipe. Mirrors stdin vs stdout
    posix_spawn_file_actions_adddup2(&spawn_actions, pipes[1], 1);
    // Ensure pipes close
    posix_spawn_file_actions_addclose(&spawn_actions, pipes[1]);
    posix_spawn_file_actions_addclose(&spawn_actions, pipes[0]);

    ret = posix_spawn(&spawned_pid, "/bin/sh", &spawn_actions, &attrs, (char *const[]){"sh", "-c", "--", "ls /var/", NULL}, environ);
    if (ret)
    {
        printf("Failed to spawn! errno: %d\n", ret);
    }
    posix_spawn_file_actions_destroy(&spawn_actions);
    posix_spawnattr_destroy(&attrs);

    int wait_status = 0;
    do
    {
        wait_status = 0;
        char val[80] = {0};
        struct pollfd polls = {.events = POLLIN, .fd = pipes[0]};
        // Poll for < 100ms, if we timeout on having any data whatsoever, we check if the process is done, if the process is done, exit the read loop.
        int ret = poll(&polls, 1, 100);
        if (ret > 0)
        {
            if (polls.revents & POLLIN)
            {
                int success = read(pipes[0], val, sizeof(val) - 1);
                printf("%s", val);
                if (success < 1)
                {
                    break;
                }
            }
        }
        if (ret == 0)
        {
            waitpid(spawned_pid, &wait_status, WUNTRACED);
            if (!(!WIFEXITED(wait_status) && !WIFSIGNALED(wait_status) && !WIFSTOPPED(wait_status)))
            {
                break;
            }
        }
    } while (1);
    close(pipes[0]);
    close(pipes[1]);
}

I have verified in WSL that this prints the exact output of ls /var/ on my machine.
I'm going to incorporate this now that I have it into my code for this PR since I now realize my previous attempt was not even close to successful.

[LADSoft]

😄

[chuggafan]

Minor update:
I've integrated the aforementioned code, current status is that it is able to run once, before getting a return of "EBADF" on the 2nd run, I have no idea what is causing it, and I've dug as far as the linux kernel clone3 syscall itself, as I'm getting EBADF off of the posix_spawn call, and not the adddup2 call, I have literally no idea what's going on there.
I likely will want an actual linux box for future testing on this as this is... weird, and possibly has some weird WSL custom kernel shenanigans at play instead of the mainline kernel here, and I may shop around for some extra hardware to make that happen in the near future.
But this is a basic status update.

[chuggafan]

Well... I got back to this.
I think I found my answer to this weird question by running omake on the OrangeC repo:

Failed to spawn, errno: 2, err: No such file or directory, command: .\omake\omake.exe -f \home\user\OrangeC\src\treetop.mak createdirs
Failed to spawn, errno: 9, err: Bad file descriptor, command: .\omake\omake.exe -f \home\user\OrangeC\src\treetop.mak library
Failed to spawn, errno: 9, err: Bad file descriptor, command: .\omake\omake.exe -f \home\user\OrangeC\src\treetop.mak exefile

On unix systems, this should default to forward slashes, I'll have to search for that logic somewhere....