ELGG: Disable Email Confirmation for User Registration

How to disable Email Confirmations for new user registration in ELGG:

1) Navigate to you ELGG installation directory (mine is /var/www/elgg_1_8_1).

2) Navigate to the 'mod' folder.

3) Delete the 'uservalidationbyemail' folder.

You're done!

If you want to keep this folder, but still disable email confirmations, open the file 'mod/uservalidationbyemail/start.php and change the following lines:

function uservalidationbyemail_init() {

    require_once dirname(__FILE__) . '/lib/functions.php';
to:

function uservalidationbyemail_init() {
    return;
    require_once dirname(__FILE__) . '/lib/functions.php';

Basically, bypass the entire init() function for this module by inserting a 'return' at the start. This will stop the module from registering its handlers, but keeps the module's files in place if you desire to use it in the future.

MySQL: Update on Select - Timestamp Example

There comes a time when it is appropriate to update a MySQL table when only a SELECT statement is being executed. You may be tracking the number of reads, or marking a column with the latest TIMESTAMP.

Unfortunately, there is no 'UPDATE ON SELECT' property available in MySQL to do this automatically. Instead, one must rely on executing a compound statement. In my case, my table holds proxy usage information, and it is useful to keep track of when these proxies are used. To do this, the statement I use to get a proxy is this:

SELECT proxy FROM proxy_usage;UPDATE proxy_usage SET timestamp=NOW();

There are more complicated ways to do this, but the basis is simple. You must insert an extra command into your query, and the simplest way is to separate them with a semicolon. And no, you cannot set up a trigger for select statements.

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
    NULL
  );
  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
    for(j=0;j<N;j++)
      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");
    exit(1);
  }

  context = clCreateContext(0,1,&device_id,NULL,NULL,&my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create context\n");
    exit(2);
  }

  queue = clCreateCommandQueue(context,device_id,0,&my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create command queue\n");
    exit(3);
  }

  A_mem = clCreateBuffer(context, CL_MEM_READ_WRITE,A_size, NULL, &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create buffer\n");
    exit(4);
  }

  // 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");
    exit(5);
  }
  
  // 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];" \
    "}\0";
  cl_program program = clCreateProgramWithSource(context, 1, (const char**)&program_source,NULL, &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create program\n");
    exit(5);
  }

  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);
  clGetProgramBuildInfo(program,device_id,CL_PROGRAM_BUILD_LOG,build_log_size,build_log,NULL);
    printf("%s\n",build_log);
    exit(5);
  }
  cl_kernel kernel = clCreateKernel(program, "square", &my_err);
  if(my_err != CL_SUCCESS){
    printf("Failed to create kernel\n");
    exit(5);
  }

  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");
    exit(5);
  }


  // Wait until The GPU data is loaded
  clFinish(queue);


  // 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");
    exit(5);
  }
   
  // Wait until the GPU program finishes
  clFinish(queue);

  // 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");
    exit(6);
  }
  
  clFinish(queue); 


  // Print output
  for(i=0;i<N;i++){
    for(j=0;j<N;j++)
      printf("%f ",B[i*N+j]);
    printf("\n");
  }

  // Destory Everything
  clReleaseMemObject(A_mem);      
  clReleaseCommandQueue(queue);
  clReleaseContext(context);
  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]
                          values('val1',...);
                      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
                          password=PASSWORD("NEW-ROOT-PASSWORD") 
                          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.