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...

Code Block

#include <string> 

std::string basename(const std::string& path)
{
  size_t pos = path.find_last_of('/');
  //if (pos == std::string::npos) return std::string();
  if (pos < path.size()-1) return std::string(path,pos+1);
  else return std::string();
}

...

Input from file value by value

Code Block

#include <sys/stat.h><fstream>  // for ifstream

   bool dir_exists(conststd::ifstream f("file.txt");
  std::string& dir)val;
  while (f>>val) {
     struct stat st;
    if( (stat(dir.c_str(),&st) == 0) && (((st.st_mode) & S_IFMT) == S_IFDIR) ) return true;
    return false;
  }

Check if file exists

 std::cout << "val: " << val << '\n';
  }
  f.close();

Input from file line by line

Code Block
#include <fstream> // for ifstream
Code Block
#include <fstream> // for ifstream std::ifstream f("file.txt"); if(not f.good()) ...

Input from file value by value

Code Block

#include <fstream>  // for ifstream

  std::ifstream f("file.txt");
  std::string val;
  while (f>>val) {
      std::std::string line;
  while (std::getline(f, line)) {
      std::cout << "valline: " << valline << '\n';
  }
  f.close();

Input from file line by line

Code Block
#include <fstream> // for ifstream std::ifstream f("file.txt"); std::string line; while (std::getline(f, line)) { std::cout << "line: " << line << '\n'; } f.close();

Print long space or repeated character

std::cout << std::setw(80) << " " << std::setw(4);

std::cout << std::setw(20) << setfill('=') << '=';

Bit operations

Print long space or repeated character

std::cout << std::setw(80) << " " << std::setw(4);

std::cout << std::setw(20) << setfill('=') << '=';

Bit operations

Check if the n-th bit is on: if( m_print_bits & (Check if the n-th bit is on: if( m_print_bits & (1 << n) ) ...

Set n-th bit: mask |= (1 << n)

Clear n-th bit: bit_fld &= ~(1 << n)

Toggle (swap 0<->1) n-th bit: bit_fld ^= (1 << n)

Check if the element is in the vector or list

...

Code Block

#include <getopt.h>
#include <stdio.h>
#include <iostream>
//===================
void usage(char* name) {
  std::cout << "Usage: " << name << " [-a <aaa>] [-b <bbb>] [-c <ccc>] [-h] <p1> [<p2> [<p3> ...]] \n";
}
//===================
int main (int argc, char **argv)
{
    char *avalue = NULL;
    char *bvalue = NULL;
    char *cvalue = NULL;
    int index;
    int c;
    extern char *optarg;
    extern int optind, optopt, opterr;

    while ((c = getopt (argc, argv, ":a:b:c:h")) != -1)
        switch (c)
        {
          case 'a':
            avalue = optarg;
            printf ("a: avalue = %s\n",avalue);
            break;
          case 'b':
            bvalue = optarg;
            printf ("b: bvalue = %s\n",bvalue);
            break;
          case 'c':
            cvalue = optarg;
            printf ("c: cvalue = %s\n",cvalue);
            break;
          case 'h':
            printf ("h: ");
	    usage(argv[0]);
            break;
          case ':':
            printf ("(:) Option -%c requires an argument.\n", optopt);
	    usage(argv[0]);
            return EXIT_FAILURE;
          case '?':
            printf ("?: Option -%c requires an argument.\n", optopt);
	    usage(argv[0]);
            return EXIT_FAILURE;
          default:
            printf ("default: You should not get here... option -%c .\n", optopt);
            abort ();
        }

    printf ("End of options: avalue = %s, bvalue = %s, cvalue = %s\n",
            avalue, bvalue, cvalue);

    for (index = optind; index < argc; index++)
        printf ("Non-option argument %s\n", argv[index]);
    return EXIT_SUCCESS;
}

Iterate over files in the directory

Using `opendir`, `readdir`, `closedir` from `STL`

Check if directory exists

Code Block

#include <iostream>
#include <dirent<sys/stat.h>

using namespace std;

int main()  bool dir_exists(const std::string& dir)
  {
    struct stat st;
   DIR*     dir;
        dirent*  pdir;

   if( (stat(dir.c_str(),&st) == 0) && (((st.st_mode) & S_IFMT) == S_IFDIR) ) return true;
    return false;
  }

Check if file exists

Code Block
#include <fstream> // for ifstream std::ifstream f("file.txt"); if(not f.good()) ...

Iterate over files in the directory

Using `opendir`, `readdir`, `closedir` from `STL`

Code Block

#include <iostream>
#include <dirent.h>
using namespace std;

int main() dir = opendir(".");      // open current directory
        while (pdir = readdir(dir)) {
        DIR*     dir;
   cout << pdir->d_name << endl  dirent*  pdir;

        }
 dir = opendir(".");       closedir(dir);
  // open current directory
      return 0;
}

Using `boost`

Code Block

#include <boost/filesystem.hpp>
namespace fs = boost::filesystem;

  fs::path path = "/reg/d/psdm/CXI/cxi49012/xtc/e158-r0150-s00-c01.xtc";
  fs::path dir  = path.parent_path(); // i.e.: /reg/d/psdm/CXI/cxi49012/xtc

  typedef fs::directory_iterator dir_iter;
  for (dir_iter dit = dir_iter(dir); dit != dir_iter(); ++ dit) {
    std::cout << dit->path().stem().string() << "\n";  
  }

Other methods of fs::path

 while (pdir = readdir(dir)) {
                cout << pdir->d_name << endl;
        }
        closedir(dir);
        return 0;
}

Using `boost`

Code Block

#include <boost/filesystem.hpp>
namespace fs = boost::filesystem;

Code Block

  fs::path path = m_path"/reg/d/psdm/CXI/cxi49012/xtc/e158-r0150-s00-c01.xtc";
  stdfs::coutpath <<dir "stem = path.parent_path(); // i.e.: /reg/d/psdm/CXI/cxi49012/xtc

  typedef fs::directory_iterator dir_iter;
  = " << path.stem().string() << "\n";            // e158-r0150-s00-c00
  for (dir_iter dit = dir_iter(dir); dit != dir_iter(); ++ dit) {
    std::cout << "extensiondit->path()   = " << path.extension.stem().string() << "\n";  
  }

Other methods of fs::path

Code Block

  fs::path path = m_path;  // .xtc
  std::cout << "filename()stem          = " << path.filenamestem().string() << "\n";            // e158-r0150-s00-c00.xtc
  std::cout << "parent_pathextension()   = " << path.parent_pathextension().string() << "\n";       // /reg/d/psdm/CXI/cxi49012/xtc

ndarray and shared pointer

Example of how to access ndarray data in psana module through the shared pointer and construct ndarray<const T,NDim>

Code Block

    .xtc
  std::cout << "filename()    shared_ptr< ndarray<T,NDim> > shp = evt.get(m_source, m_key, &m_src);
= " << path.filename().string() << "\n";        if (shp.get()) {

          ndarray<T,NDim>* pnda = shp.get();
// e158-r0150-s00-c00.xtc
  std::cout << "parent_path() = " << path.parent_path().string() << "\n";     // /reg/d/psdm/CXI/cxi49012/xtc

ndarray and shared pointer

Example of how to access ndarray data in psana module through the shared pointer and construct ndarray<const T,NDim>

Code Block

     ndarray<const  T,NDim> nda_const(pnda->data(), pnda->shape());

shared_ptr< ndarray<T,NDim> > shp = evt.get(m_source, m_key, &m_src);
          ndarray<const T,NDim> nda_const(shp->data(), shp->shape());
if (shp.get()) {

          }

Singleton

InputParameters.h :

Code Block

#include <iostream> // for cout

class InputParameters  {
public:
  static InputParameters* instance();
  void print();

private:
  InputParameters () ;ndarray<T,NDim>* pnda = shp.get();
          ndarray<const T,NDim> nda_const(pnda->data(), pnda->shape());

          ndarray<const T,NDim> nda_const(shp->data(), shp->shape());
        }

Singleton

InputParameters.h :

Code Block

#include <iostream> // !!!!! Private so that it can not be called from outside
  for cout

class InputParameters  {
public:
  static InputParameters* instance();
  void print();

private:
  InputParameters () ;                 // !!!!! Private so that it can not be called from outside
  virtual ~InputParameters () {}; 

  static InputParameters* m_pInstance; // !!!!! Singleton instance

  // Copy constructor and assignment are disabled by default
  InputParameters ( const InputParameters& ) ;
  InputParameters& operator = ( const InputParameters& ) ;
};

...

Declaration, Initialization, Definition of static const parameters

Code Block
// .h : class A { public: static const int INT_PAR = 185; static const double DOUBLE_PAR; } // .cpp : const int A::INT_PAR; const double A::DOUBLE_PAR = 109.92;

Issue OS command from C++

Use method system

Code Block
// int system (const char* command); #include <stdlib.h> /* system, NULL, EXIT_FAILURE */ int status = system ("ls -l");

Use method popen

Code Block

#include <string>
#include <iostream>
#include <stdio.h>

std::string exec(char* cmd) {
    FILE* pipe = popen(cmd, "r");
    if (!pipe) return "ERROR";
    char buffer[128];
    std::string result = "";
    while(!feof(pipe)) {
    	if(fgets(buffer, 128, pipe) != NULL)
    		result += buffer;
    }
    pclose(pipe);
    return result;
}

...

parameters

Code Block
// .h : class A { public: static const int INT_PAR = 185; static const double DOUBLE_PAR; } // .cpp : const int A::INT_PAR; const double A::DOUBLE_PAR = 109.92;

Issue OS command from C++

Use method system

Code Block
// int system (const char* command); #include <stdlib.h> /* system, NULL, EXIT_FAILURE */ int status = system ("ls -l");

Use method popen

Code Block

#include <string>
#include <iostream>
#include <stdio.h>

std::string exec(char* cmd) {
    FILE* pipe = popen(cmd, "r");
    if (!pipe) return "ERROR";
    char buffer[128];
    std::string result = "";
    while(!feof(pipe)) {
    	if(fgets(buffer, 128, pipe) != NULL)
    		result += buffer;
    }
    pclose(pipe);
    return result;
}

Valgrind - analysis of job memory consumption

Code Block
valgrind --tool=massif --time-unit=B psana -n 1 -m ImgAlgos.PixCoordsProducer exp=cxi86415:run=62

this command runs the job and produces the file like massif.out.23864, which can be printed by command:

Code Block
ms_print massif.out.23864

Building C/C++ library using distutils.core setup, Extension

http://stackoverflow.com/questions/16854066/using-distutils-and-build-clib-to-build-c-library

Instead of passing a library name as a string, pass a tuple with the sources to compile:

Code Block

# setup.py
#__________

import sys
from distutils.core import setup
from distutils.command.build_clib import build_clib
from distutils.extension import Extension
from Cython.Distutils import build_ext

libhello = ('hello', {'sources': ['hello.c']})  # <<<<==============

ext_modules=[
    Extension("demo", ["demo.pyx"])
]

setup(
        name = 'demo',
        libraries = [libhello],
        cmdclass = {'build_clib': build_clib, 'build_ext': build_ext},
        ext_modules = ext_modules
)
#__________

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Versions Compared

Old Version 28

New Version Current

Key

Input from file value by value

Check if file exists

Input from file line by line

Input from file value by value

Input from file line by line

Print long space or repeated character

Bit operations

Print long space or repeated character

Bit operations

Check if the element is in the vector or list

Iterate over files in the directory

Using `opendir`, `readdir`, `closedir` from `STL`

Check if directory exists

Check if file exists

Iterate over files in the directory

Using `opendir`, `readdir`, `closedir` from `STL`

Using `boost`

Using `boost`

ndarray and shared pointer

ndarray and shared pointer

Singleton

Singleton

Declaration, Initialization, Definition of static const parameters

Issue OS command from C++

Use method system

Use method popen

parameters

Issue OS command from C++

Use method system

Use method popen

Valgrind - analysis of job memory consumption

Building C/C++ library using distutils.core setup, Extension

Using C++ in Cython

Page tree

Page History

Versions Compared

Old Version 28

New Version Current

Key

Input from file value by value

Check if file exists

Input from file line by line

Input from file value by value

Input from file line by line

Print long space or repeated character

Bit operations

Print long space or repeated character

Bit operations

Check if the element is in the vector or list

Iterate over files in the directory

Using opendir, readdir, closedir from STL

Check if directory exists

Check if file exists

Iterate over files in the directory

Using opendir, readdir, closedir from STL

Using boost

Using boost

ndarray and shared pointer

ndarray and shared pointer

Singleton

Singleton

Declaration, Initialization, Definition of static const parameters

Issue OS command from C++

Use method system

Use method popen

parameters

Issue OS command from C++

Use method system

Use method popen

Valgrind - analysis of job memory consumption

Building C/C++ library using distutils.core setup, Extension

Using C++ in Cython

Using `opendir`, `readdir`, `closedir` from `STL`

Using `opendir`, `readdir`, `closedir` from `STL`

Using `boost`

Using `boost`