Question: When downloading big files it necessary to pause the download many times. A big file can be downloaded by using `wget`. First start download, then kill `wget`, then resume download by `wget -c`.  

I want to pause downloads too many times depending on events such as power failure, Network unavailability, etc... and want to automate it using a script. So pressing `Ctrl+C` is't an option. I know a process can be paused by `kill -STOP "$pid"` The pausing should not close the connection to the website, either it should wait for resume command or the bandwidth throttled to very low data useage. 

[How to pause aria2 download](https://askubuntu.com/questions/270744/how-to-pause-a-running-aria-download) is a partial solution but option *pause* is not supported in my `aria2` (1.8.0, Ubuntu 10.04 LTS) and I can't upgrade `aria2` (From apt-get install or manually install ). This RPC option for `aria2` seems to works from *Ubuntu 11.10*. So a portable version of `aria2` is also considerable.

**Looking for**  

I'm looking for a download manager which is capable of **throttle bandwidth and pause/resume** all (or one ) the running instance of download upon execution of a `--throttle=10K`, `--pasue` switch or something like that, and resume it on a `--resume` switch (Or using other ways such as RPC). 

I know `killall -9 $(pidof downloader)` should stop all downloads and can be resumed from the last point. But this only a bad choice for me as the number pause/resume is too high and the time to make connection to the server (where download file locate ) is a wastage of time and bandwidth. 

`aria1` can do some job by `--stop` switch. But it's obsolete and solves it partially.

Answer: 
Finally I solved the question (Thanks @rostislav-stribrny )

**JDownloader** is capable of *handling running instance of download* (throttle, pasue, resume, add etc) .

1. [Download](http://jdownloader.org/download/index) and install JDownloader (Tested in v0.9)
2. Launch it
3. Install add-on **JD Remote Control** (Addons -> Addons manager-> JD remote)
4. Enable JD Remote Control (Addons -> (tick))
5. goto `http://127.0.0.1:10025/help or http://localhost:10025/help` ( IP:port )

**Example**  

To **throttle** all running download to 10K `http://localhost:10025/action/set/download/limit/10`
From terminal `wget http://localhost:10025/action/set/download/limit/10`  

To **pause** : `wget http://localhost:10025/action/pause`
I am user of fatrat. Thats the best download managee I have in Ubuntu . Fatrat low in size and best in performance.

```
sudo apt-get install fatrat

```

the above command will install the fatrat.