Hi. I have not done any multi-threaded programming before. What I basically want is to read into the output of a long shellExecute function each second.

In details, I am calling shellExecute("pkexec dd if=/path/to/file of=/dev/sdx status=progress && sync");
It's a long running process and dd command prints how many bytes it has written in stdout continuously. I want to read and parse this output each second. How should I proceed?

On Saturday, 10 November 2018 at 15:05:38 UTC, helxi wrote:
> Hi. I have not done any multi-threaded programming before. What I basically want is to read into the output of a long shellExecute function each second.
>
> In details, I am calling shellExecute("pkexec dd if=/path/to/file of=/dev/sdx status=progress && sync");
> It's a long running process and dd command prints how many bytes it has written in stdout continuously. I want to read and parse this output each second. How should I proceed?

shellExecute won't work, because it waits for the process to end before moving on.

I believe https://dlang.org/phobos/std_process.html#pipeProcess should do what you want. It returns a ProcessPipes object which has stdout, from which you should be able to read.

On Saturday, 10 November 2018 at 15:54:07 UTC, JN wrote:
> On Saturday, 10 November 2018 at 15:05:38 UTC, helxi wrote:
>> Hi. I have not done any multi-threaded programming before. What I basically want is to read into the output of a long shellExecute function each second.
>>
>> In details, I am calling shellExecute("pkexec dd if=/path/to/file of=/dev/sdx status=progress && sync");
>> It's a long running process and dd command prints how many bytes it has written in stdout continuously. I want to read and parse this output each second. How should I proceed?
>
> shellExecute won't work, because it waits for the process to end before moving on.
>
> I believe https://dlang.org/phobos/std_process.html#pipeProcess should do what you want. It returns a ProcessPipes object which has stdout, from which you should be able to read.

Okay I looked it up but now I have another question

     1	import std.process;
     2	import std.stdio;
     3	import std.range;
     4	import std.string;
     5	
     6	//    pkexec dd if=/run/media/user1101/portable_drive/software/os/manjaro-kde-18.0-stable-x86_64.iso of=/dev/sdd bs=4M status=progress 2>&1 && sync
     7	
     8	void main() {
     9	    auto pipe = pipeShell("bash", Redirect.stdout | Redirect.stderr | Redirect.stdin);
    10	    pipe.stdin.writeln(
    11	        "pkexec dd if=/run/media/user1101/portable_drive/software/os/manjaro-kde-18.0-stable-x86_64.iso of=/dev/sdd bs=4M status=progress 2>&1 && sync"
    12	    );
    13	    pipe.stdin.flush();
    14	    pipe.stdin.close();
    15	
    16	    foreach (line; pipe.stdout.byLineCopy)
    17	        foreach (word; line.split)
    18	            writeln(word);
    19	}

What I want is to instantly print whatever dd prints to the stdout. (I made dd to redirect output to stdout with 2>&1 already). But the problem is, the pipe waits until dd finishes writing to stdout. How can I make the pipe not wait for dd to finish?

}