OpenCL Tutorial - Introduction to OpenCL programming

OpenCL is a C programming library suited for multithreaded programming on newer Graphics Processing Units. It enables programmers to optimize their applications by utilizing the hundreds of processing cores within higher-end GPUs.

Find your OpenCL platform
The following function will locate your OpenCL platform or alert you if one cannot be found:
cl_platform_id getPlatformID()
  cl_platform_id plat_id;
  cl_uint my_err = clGetPlatformIDs(1, &plat_id, NULL);
  if(my_err != CL_SUCCESS)
    printf("Could not find OpenCL platform\n");
    plat_id = NULL;
  return plat_id;

Find your OpenCL supported GPU
The following function will locate your GPU or alert you if no supported GPU is found on your platform:
cl_device_id getGPUID(cl_platform_id plat_id)
  cl_device_id dev_id;             // The ID of the GPU device
  cl_uint my_err = clGetDeviceIDs( // Get an openCL device
    plat_id,                       // The platform ID  
    CL_DEVICE_TYPE_GPU,            // Ignore CPUs, etc.
    1,                             // Just one for now
    &dev_id,                       // Place ID here
  if(my_err != CL_SUCCESS){
    printf("Could find supported GPU\n");
    dev_id = NULL;
  return dev_id;

Square each element of a 2D array with your GPU

The following program utilizes the above functions to square each element of a 2D array
int main()
  int i,j;
  int N = 10;                      // Array Size (NxN
  int A_size = sizeof(float)*N*N;  // Size in bytes
  float *A = malloc(A_size);       // Storage for input array
  float *B = malloc(A_size);
       // Storage for output array

  for(i=0;i<N;i++)                 // Initialize input array
      A[i*N+j] = i+j;

  cl_mem A_mem,B_mem;              // OpenCL memory objects
  cl_uint my_err;                  // Error catching
  cl_device_id device_id;          // GPU ID
  cl_context context;    
  cl_command_queue queue;

  device_id = getGPUID(getPlatformID());
  if(device_id == NULL){
    printf("Could not find supported platform or device.\n");

  context = clCreateContext(0,1,&device_id,NULL,NULL,&my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create context\n");

  queue = clCreateCommandQueue(context,device_id,0,&my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create command queue\n");

  A_mem = clCreateBuffer(context, CL_MEM_READ_WRITE,A_size, NULL, &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create buffer\n");

  // Load Input Array onto GPU
  my_err = clEnqueueWriteBuffer(queue, A_mem, CL_TRUE, 0,A_size, (void *)A,0, NULL, NULL);
  if(my_err != CL_SUCCESS){
    printf("Failed to enqueue write buffer\n");

  // Program to run on the GPU
  char *program_source = "__kernel void square( __global float * A, int N){" \
    "int id0=get_global_id(0);" \
    "int id1=get_global_id(1);" \
    "A[id0*N+id1] *= A[id0*N+id1];" \
  cl_program program = clCreateProgramWithSource(context, 1, (const char**)&program_source,NULL, &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create program\n");

  my_err = clBuildProgram(program, 0, NULL, NULL, NULL, NULL);
  if(my_err != CL_SUCCESS){
    printf("Failed to build program\n");
    int build_log_size = sizeof(char)*10000;
    char * build_log = malloc(build_log_size);
  cl_kernel kernel = clCreateKernel(program, "square", &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create kernel\n");

  my_err = clSetKernelArg(kernel,  0, sizeof(cl_mem), &A_mem);
  my_err |= clSetKernelArg(kernel,  1, sizeof(int), &N);
  if(my_err != CL_SUCCESS){
    printf("Failed to set kernel args\n");

  // Wait until The GPU data is loaded

  // Queue the GPU program
  my_err = clEnqueueNDRangeKernel(queue, kernel, 2, NULL,&N, NULL, 0, NULL, NULL);
  if(my_err != CL_SUCCESS){
    printf("Failed to enqueue kernel\n");

  // Wait until the GPU program finishes

  // Read data from GPU
  my_err = clEnqueueReadBuffer( 

    queue, A_mem, CL_TRUE, 0, 
    A_size, B, 0, NULL, NULL
  if(my_err != CL_SUCCESS){
    printf("Failed to enqueue read buffer\n");


  // Print output
      printf("%f ",B[i*N+j]);

  // Destory Everything

  return 0;

Nature is Infinite in its Intricacy

7zip Linux Installation - Install 7zip on Ubuntu - Debian - FreeBSD - Fedora - Redhat

In the Linux world, 7zip manifests as the p7zip package. It can be used as a command line utility, and it integrates itself into your GUI package manager automatically.

Ubuntu and Debian 7zip installation:
sudo apt-get install p7zip

Fedora and Redhat 7zip installation:
yum install p7zip

FreeBSD 7zip installation
pkg_add -r p7zip

Nature is Infinite in its Intricacy

MySQL Cheat Sheet - The Essential Commands for MySQL Administration

## Mysql Cheat Sheet ##

install: sudo apt-get install mysql
  lamp stack: sudo tasksel install lamp-server

run: mysql -u root -p

database functions:   show databases;
                      use [database name];
                      create database [database name];
                      drop database [database name];

table functions:      show tables;
                      describe [table name];
                      create table [table name] 

                          ([row1 name] [row1 type],...);
                      drop table [table name];

data functions:       load data local infile 'file path.txt' 

                          INTO TABLE [table name];
                      insert into [table name]

                      delete from [table name] where [condition];
                      update [table name] set [token] = 

                        [value] where [condition];

user functions:       create user '[username]'@'[hostname]' 

                          identified by '[password]';
                      create user '[username]'@'%' 

                          identified by '[password]';
                      GRANT ALL PRIVILEGES ON [database].[table]

                          TO '[username]'@'[hostname]';
                      GRANT ALL PRIVILEGES ON *.* 

                          TO '[username]'@'[hostname]';
                      revoke ALL PRIVILEGES ON [database].[table]

                          from '[username]'@'[host]';
                      rename user '[username]'@'[hostname]' 

                          to '[username]'@'[hostname]'      

import functions:     load data local infile '[full path]' 

                          into table [table name];

reset password:       /etc/init.d/mysql stop
                      mysqld_safe --skip-grant-tables &
                      mysql -u root
                      mysql> use mysql;
                      mysql> update user set

                          where User='root';
                      mysql> flush privileges;
                      mysql> quit
                      /etc/init.d/mysql stop
                      /etc/init.d/mysql start

## Other Good MySQL Cheat Sheets ##
Stephen Scott's MySQL Cheat Sheet 

Nature's Intricacy is Infinite, says the succulent.