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digitalmars.D.learn - How do I create a fileWatcher with an onFileChange event using spawn?

reply Enjoys Math <enjoysmath gmail.com> writes:
Something like this:


module file_watcher;

import std.concurrency;
import std.file;
import std.signals;
import std.datetime;


void fileWatcher(Tid tid, string filename, int loopSleep) {
	auto modified0 = timeLastModified(filename);

	while (true) {
		modified = timeLastModified(filename);
			
		if (modified > modified0) {
			modified0 = modified;
			//if (onFileChange !is null)
			//    onFileChange(receiver);
		}

		sleep(dur!"msecs"(loopSleep));
	}
}


But I'm not sure how to send the onFiledChange event.
Aug 25 2017
next sibling parent reply Jacob Carlborg <doob me.com> writes:
On 2017-08-25 23:25, Enjoys Math wrote:

 
 
 Something like this:
 
 
 module file_watcher;
 
 import std.concurrency;
 import std.file;
 import std.signals;
 import std.datetime;
 
 
 void fileWatcher(Tid tid, string filename, int loopSleep) {
      auto modified0 = timeLastModified(filename);
 
      while (true) {
          modified = timeLastModified(filename);
 
          if (modified > modified0) {
              modified0 = modified;
              //if (onFileChange !is null)
              //    onFileChange(receiver);
          }
 
          sleep(dur!"msecs"(loopSleep));
      }
 }
 
 
 But I'm not sure how to send the onFiledChange event.


A delegate perhaps?

Or you can look at any of the existing event driven libraries that do this:

http://code.dlang.org/packages/vibe-core
http://code.dlang.org/packages/libasync

-- 
/Jacob Carlborg
Aug 27 2017
next sibling parent reply Nemanja Boric <4burgos gmail.com> writes:
On Monday, 28 August 2017 at 06:27:20 UTC, Jacob Carlborg wrote:

 On 2017-08-25 23:25, Enjoys Math wrote:

 
 
 Something like this:
 
 
 module file_watcher;
 
 import std.concurrency;
 import std.file;
 import std.signals;
 import std.datetime;
 
 
 void fileWatcher(Tid tid, string filename, int loopSleep) {
      auto modified0 = timeLastModified(filename);
 
      while (true) {
          modified = timeLastModified(filename);
 
          if (modified > modified0) {
              modified0 = modified;
              //if (onFileChange !is null)
              //    onFileChange(receiver);
          }
 
          sleep(dur!"msecs"(loopSleep));
      }
 }
 
 
 But I'm not sure how to send the onFiledChange event.


 A delegate perhaps?

 Or you can look at any of the existing event driven libraries 
 that do this:

 http://code.dlang.org/packages/vibe-core
 http://code.dlang.org/packages/libasync


In addition, to avoid polling, it's possible to register yourself 
to the operating system so it will tell you when a modification 
on the given file has happened: 
https://msdn.microsoft.com/en-us/library/aa364417%28VS.85%29.aspx?f=255&M
PPError=-2147217396 http://man7.org/linux/man-pages/man7/inotify.7.html
Aug 27 2017
parent reply Jacob Carlborg <doob me.com> writes:
On 2017-08-28 08:31, Nemanja Boric wrote:

 On Monday, 28 August 2017 at 06:27:20 UTC, Jacob Carlborg wrote:

 http://code.dlang.org/packages/vibe-core
 http://code.dlang.org/packages/libasync


 
 In addition, to avoid polling, it's possible to register yourself to the 
 operating system so it will tell you when a modification on the given 
 file has happened: 
 https://msdn.microsoft.com/en-us/library/aa364417%28VS.85%29.aspx?f=255&M
PPError=-2147217396 
 http://man7.org/linux/man-pages/man7/inotify.7.html


That's what the two libraries above provides, in a cross-platform way.

-- 
/Jacob Carlborg
Aug 28 2017
parent bauss <jj_1337 live.dk> writes:
On Monday, 28 August 2017 at 11:25:03 UTC, Jacob Carlborg wrote:

 On 2017-08-28 08:31, Nemanja Boric wrote:

 On Monday, 28 August 2017 at 06:27:20 UTC, Jacob Carlborg 
 wrote:

 http://code.dlang.org/packages/vibe-core
 http://code.dlang.org/packages/libasync


 
 In addition, to avoid polling, it's possible to register 
 yourself to the operating system so it will tell you when a 
 modification on the given file has happened: 
 https://msdn.microsoft.com/en-us/library/aa364417%28VS.85%29.aspx?f=255&M
PPError=-2147217396 http://man7.org/linux/man-pages/man7/inotify.7.html


 That's what the two libraries above provides, in a 
 cross-platform way.


There's already a dub package for file system watching:

https://code.dlang.org/packages/fswatch
Nov 13 2017
prev sibling parent Enjoys Math <enjoysmath gmail.com> writes:
On Monday, 28 August 2017 at 06:27:20 UTC, Jacob Carlborg wrote:

 On 2017-08-25 23:25, Enjoys Math wrote:

 
 
 Something like this:
 
 
 module file_watcher;
 
 import std.concurrency;
 import std.file;
 import std.signals;
 import std.datetime;
 
 
 void fileWatcher(Tid tid, string filename, int loopSleep) {
      auto modified0 = timeLastModified(filename);
 
      while (true) {
          modified = timeLastModified(filename);
 
          if (modified > modified0) {
              modified0 = modified;
              //if (onFileChange !is null)
              //    onFileChange(receiver);
          }
 
          sleep(dur!"msecs"(loopSleep));
      }
 }
 
 
 But I'm not sure how to send the onFiledChange event.


 A delegate perhaps?

 Or you can look at any of the existing event driven libraries 
 that do this:

 http://code.dlang.org/packages/vibe-core
 http://code.dlang.org/packages/libasync


No a plain delegate won't work.  There's something you're not 
telling me because I've tried delegates.  They have to be shared 
or something, and that causes a big mess with my code.
Aug 28 2017
prev sibling parent shuji <cravstar hotmail.com> writes:
On Friday, 25 August 2017 at 21:25:37 UTC, Enjoys Math wrote:

 Something like this:


 module file_watcher;

 import std.concurrency;
 import std.file;
 import std.signals;
 import std.datetime;


 void fileWatcher(Tid tid, string filename, int loopSleep) {
 	auto modified0 = timeLastModified(filename);

 	while (true) {
 		modified = timeLastModified(filename);
 			
 		if (modified > modified0) {
 			modified0 = modified;
 			//if (onFileChange !is null)
 			//    onFileChange(receiver);
 		}

 		sleep(dur!"msecs"(loopSleep));
 	}
 }


 But I'm not sure how to send the onFiledChange event.


 Nemanja Boric I would not recommend calling those APIs on 
Windows because they work on entire directories, not suitable for 
individual files and sometimes  those functions not even work 
when other programs change the files in a non standard way (that 
has happened to me before when editing through a text editor)
 Enjoys Math The way I usually deal with this problem is I save 
the filename, the time and handler function in an associative 
array and loop through when something changes, this way you can 
delete, sort, etc on the map when the files are deleted or so.
Hope this helps a little.
Nov 12 2017