Bitcoin Mining for Fun results

So yesterday my ASICMiner Block Erupter USB 330MH/s Sapphire Miner arrived in the mail, much earlier than I planned I may add.

I went ahead and plugged it in to my Arch Linux tower, and fired up cgminer.

IMG_20131110_100913

With no further hacking cgminer noticed the card and began mining with it.

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 [P]ool management [S]ettings [D]isplay options [Q]uit
 AMU 0:                | 335.4M/335.7Mh/s | A:5760 R:12 HW:74 WU: 4.6/m
--------------------------------------------------------------------------------

I went ahead and left the mining over night (roughly about 24 hours) connected to the BTC Guild mining pool.

With my 330Mh/s card, and roughly 24 hours, I was able to mass 0.00027419 BTC. In US currency, with the current rate of bitcoin ($318 per coin) this is $0.09.

Using this math that would be about $32.85 a year ($0.09 x 365).

So in about 6 months I will of paid off my ASICMiner Block Erupter USB 330MH/s Sapphire Miner, please note this does not include electricity to run my PC.

 

Python Running System Command

So there are a few ways to run system command using python, but I tend to find the below approach the easiest to use and has error handling.

First off I would create a function rather than running the commands over and over:

import subprocess

def run(command):
    '''takes a string command and hands back a subprocess object'''
    process = subprocess.Popen(command.split(), shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    process.wait()
    return process

The function itself is pretty small and makes use of the subprocess library.

Popen takes a list which is each part of your command, for example the command ls -lt file would be written as:

['ls', '-lt', 'file']

This however is avoided by using the split method on our function input.

Once we have our function loaded the usage is pretty easy:

>>> c = run('pwd')
>>> c
< subprocess.Popen object at 0x1004a3c50>

Like mentioned above Popen returns a subprocess object, not the result of your command. To access the results and other useful information we are just a method away:

>>> c.communicate()
('/Users/jeffreyness\n', '')

The real beauty I find in using this approach is error handling, something os.system doesn’t provide. Using our object we can check the returncode and validate everything ran cleanly:

>>> c.returncode
0

A return code of 0 is telling us an error was not returned, but what would happen if something did happen:

>>> c = run('ls -ld not_a_file_here.txt')
>>>
>>> c.communicate()
('', 'ls: not_a_file_here.txt: No such file or directory\n')
>>>
>>> c.returncode
1

A return code greater than 0 tells us something went wrong.

Lets see that same command work properly:

>>> c = run('ls -ld Desktop')
>>>
>>> c.communicate()
('drwx------+ 42 jeffreyness  staff  1428 Nov  9 10:35 Desktop\n', '')
>>>
>>> c.returncode
0

Now isn’t that slick!

Using this approach you may want to write blocks of commands something like this:

command = 'ls -ld not_a_file_here.txt'
try:
    c = run(command)
except OSError as e:
    raise(e)

if c.returncode > 0:
    print 'Error: we received a return code of %s' % c.returncode
else:
    print c.communicate()