On Tue, 18 Jun 2013 17:41:57 -0400, Timothee Cour
<thelastmamm...@gmail.com> wrote:
I'd like to do the following:
auto pipes = pipeShell(command, Redirect.stdout | Redirect.stderr);
while(true){
version(A1)
string line=pipes.stdout.readln;
version(A2)
auto line=pipes.stdout.readChunk(10);
version(A3)
auto line=pipes.stdout.readChar();
// do something with line
if(tryWait(pipes.pid).terminated)
break;
}
The problem is that 'string line=pipes.stdout.readln;' seems to block
until
the process is terminated, ie if the command is a long running command
that
prints a line every 1 second for 10 seconds, this program will wait 10
seconds before starting the processing.
I also tried with rawRead, readf, fgetc but couldn't make it work.
I'm on OSX, if that matters.
Is there any way to achieve this?
I think the issue is on the child process side. If you are using buffered
I/O you have to flush the buffer.
For instance, if the child is using D writeln or C printf, and you are
using stdout, then it will only flush after writing 4096 bytes. You can
flush early by calling flush on stdout, or fflush in C. Note that C will
auto-detect if it is an interactive console, and flush via newlines
instead. So running the same program from the console will flush every
line!
Alternatively, you can set the flush policy to flush after every line.
See here:
https://developer.apple.com/library/ios/#documentation/System/Conceptual/ManPages_iPhoneOS/man3/setvbuf.3.html
And here:
http://dlang.org/phobos/std_stdio.html#.File.setvbuf
-Steve
