www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Getting familiar with std.process

reply jmh530 <john.michael.hall gmail.com> writes:
I haven't used std.process before and am trying to play around 
with it.

In the code below, the first file writes some text to an output 
file. My goal is to be able to read what is written to that file 
without creating the file itself. I'm not sure it's possible, but 
the second file is my attempt.

The second file compiles the first (for the sake of simplicity), 
then creates a pipe with program it compiles, piping the result 
to stdout, then it saves the result to an output string, which I 
then print (or potentially manipulate in some other way in the 
future). But it doesn't print anything (why I'm posting here).

I think the issue is that create_file doesn't write to stdout, it 
writes to file. Other than reading the file and then deleting it, 
I don't know what else to try.

//create_file.d

import std.stdio : toFile;

void main()
{
	toFile("test", "output.txt");
}

//read_file.d
//read_file.d

import std.process;
import std.stdio;

void main()
{
	auto command1 = execute(["dmd", "create_file.d"]);
	//auto command2 = execute(["create_file.exe"]);
	
	auto pipes = pipeProcess("create_file.exe", Redirect.stdout);
	scope(exit) wait(pipes.pid);
	
	foreach (line; pipes.stdout.byLine) writeln(line);
}
Feb 09
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 02/09/2017 12:44 PM, jmh530 wrote:

 I think the issue is that create_file doesn't write to stdout, it writes
 to file.
Correct. Pipe works by piping the standard input/output streams.
 Other than reading the file and then deleting it, I don't know
 what else to try.
create_file must write to its stdout. Ali
Feb 09
parent jmh530 <john.michael.hall gmail.com> writes:
On Thursday, 9 February 2017 at 21:36:46 UTC, Ali Çehreli wrote:
 On 02/09/2017 12:44 PM, jmh530 wrote:

 I think the issue is that create_file doesn't write to
stdout, it writes
 to file.
Correct. Pipe works by piping the standard input/output streams.
 Other than reading the file and then deleting it, I don't know
 what else to try.
create_file must write to its stdout. Ali
If only it were that easy. It's not my program writing to file, it's some one I didn't write. This was just sort of a beta test. I might need to look into the program a bit more.
Feb 09