libigl_Martin/stdin_to_temp.h

#ifndef IGL_STDIN_TO_TEMP
#define IGL_STDIN_TO_TEMP
#include <cstdio>
namespace igl
{
  // Write stdin/piped input to a temporary file which can than be preprocessed as it
  // is (a normal file). This is often useful if you want to process stdin/piped
  // with library functions that expect to be able to fseek(), rewind() etc..
  //
  // If your application is not using fseek(), rewind(), etc. but just reading
  // from stdin then this will likely cause a bottle neck as it defeats the whole
  // purpose of piping.
  //
  // Outputs:
  //   temp_file  pointer to temp file pointer, rewound to beginning of file so
  //     its ready to be read
  // Return true only if no errors were found
  //
  // Note: Caller is responsible for closing the file (tmpfile() automatically
  // unlinks the file so there is no need to remove/delete/unlink the file)
  inline bool stdin_to_temp(FILE ** temp_file);
}

// IMPLEMENTATION
#include <iostream>

inline bool igl::stdin_to_temp(FILE ** temp_file)
{
  // get a temporary file
  *temp_file = tmpfile();
  if(*temp_file == NULL)
  {
    fprintf(stderr,"IOError: temp file could not be created.\n");
    return false;
  }
  char c;
  // c++'s cin handles the stdind input in a reasonable way
  while (std::cin.good())
  {
    c = std::cin.get();
    if(std::cin.good())
    {
      if(1 != fwrite(&c,sizeof(char),1,*temp_file))
      {
        fprintf(stderr,"IOError: error writing to tempfile.\n");
        return false;
      }
    }
  }
  // rewind file getting it ready to read from
  rewind(*temp_file);
  return true;
}

#endif