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# RESCAN FOR NEWLY ADDED HDS
echo "- - -" > /sys/class/scsi_host/host#/scan
fdisk -l

# NEW LOGICAL VOLUME
sudo fdisk /dev/sdb
# then create a new partition of type 8e (Linux LVM)
# create a phisical volume
sudo pvcreate /dev/sdb1
# create new volume group

stemwinder

Spawning multiple ffmpeg processes with xargs:

On standard NVIDIA GPUs (Not the Quadros and Tesla lines), NVENC encodes are limited to two simultaneous sessions. The sample below illustrates how to pass a list of AVI files to ffmpeg and encode them to HEVC on two encode sessions:

$ find Videos/ -type f -name \*.avi -print | sed 's/.avi$//' |\
  xargs -n 1 -I@ -P 2 ffmpeg -i "@.avi" -c:a aac -c:v hevc_nvenc "@.mp4"

This will find all files with the ending .avi in the directory Videos/ and transcode them into HEVC/H265+AAC files with the ending .mp4. The noteworthy part here is the -P 2 to xargs, which starts up to two processes in parallel.

stemwinder

Transient compute clustering with GNU Parallel and sshfs:

GNU Parallel is a multipurpose program for running shell commands in parallel, which can often be used to replace shell script loops,find -exec, and find | xargs. It provides the --sshlogin and --sshloginfile options to farm out jobs to multiple hosts, as well as options for sending and retrieving static resources and and per-job input and output files.

For any particular task, however, keeping track of which files need to pushed to and retrieved from the remote hosts is somewhat of a hassle. Furthermore, cancelled or failed runs can leave garbage on the remote hosts, and if input and output files are large, sending them to local disk on the remote hosts is somewhat inefficient.

In a traditional cluster, this problem would be solved by giving all nodes access to a shared filesystem, usually with NFS or something more exotic. However, NFS doesn't wo

stemwinder

<?php

/**
 * This functions runs like array_unique but is based on similarity
 * and the math is based on similar_text to know better, see: php.net/similar_text
 * 
 * @param  [type]  $array    [description]
 * @param  integer $howMuch  [description]
 * @param  [type]  $callback [description]
 * @return [type]            [description]

stemwinder

SELECT CONCAT('ALTER TABLE ', TABLE_SCHEMA, '.', TABLE_NAME, ' engine=InnoDB;') 
FROM information_schema.TABLES WHERE ENGINE = 'MyISAM';

stemwinder

# delete all FLAC files recursively
find ./* -depth -type f -name \*.flac -delete

# list all FLAC files recursively
find ./* -depth -type f -name \*.flac

# convert all FLAC files to ALAC recursively
find ./* -depth -type f -name \*.flac | parallel -j+0 --gnu nice -n 19 ffmpeg -i "{}" -c:a alac "{.}.m4a"

# convert FLAC to ALAC and strip album art

stemwinder

// http://stackoverflow.com/a/10796951
(function(XHR) {
  "use strict";

  var element = document.createElement('div');
  element.id = "interceptedResponse";
  element.appendChild(document.createTextNode(""));
  document.body.appendChild(element);

  var open = XHR.prototype.open;

stemwinder

Debug your PHP in Docker with Intellij/PHPStorm and Xdebug

1. For your local dev, create a Dockerfile that is based on your production image and simply install xdebug into it. Exemple:

FROM php:5

RUN yes | pecl install xdebug \
    && echo "zend_extension=$(find /usr/local/lib/php/extensions/ -name xdebug.so)" > /usr/local/etc/php/conf.d/xdebug.ini \

stemwinder

-- http://stackoverflow.com/a/8077952/3530438
CREATE TEMPORARY TABLE tmp SELECT * from invoices WHERE ...;
ALTER TABLE tmp drop ID; # drop autoincrement field
# UPDATE tmp SET ...; # just needed to change other unique keys
INSERT INTO invoices SELECT 0,tmp.* FROM tmp;
DROP TABLE tmp;

stemwinder

<?php

$products = Shop\Product::join('shop_products_options as po', 'po.product_id', '=', 'products.id')
   ->orderBy('po.pinned', 'desc')
   ->select('products.*')       // just to avoid fetching anything from joined table
   ->with('options')         // if you need options data anyway
   ->paginate(5);

// SELECT clause is there in order to not appending joined columns to your Product model.
// Originaly found at: http://stackoverflow.com/questions/23530051/laravel-eloquent-sort-by-relation-table-column