C++ Ostream Library - write

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Description

It is used to inserts the first n characters of the array pointed by s into the stream. This function simply copies a block of data, without checking its contents: The array may contain null characters, which are also copied without stopping the copying process.

Declaration

Following is the declaration for std::ostream::write.

ostream& write (const char* s, streamsize n);

Parameters

• s − Pointer to an array of at least n characters.

• n − Number of characters to insert.

Return Value

It returns the ostream object (*this).

Exceptions

Basic guarantee − if an exception is thrown, the object is in a valid state.

Data races

Modifies the stream objectAccess up to n characters pointed by s./p>

Example

In below example explains about std::ostream::write.

#include <fstream>

int main () {
   std::ifstream infile ("test.txt",std::ifstream::binary);
   std::ofstream outfile ("new.txt",std::ofstream::binary);

   infile.seekg (0,infile.end);
   long size = infile.tellg();
   infile.seekg (0);

   char* buffer = new char[size];

   infile.read (buffer,size);

   outfile.write (buffer,size);
 
   delete[] buffer;

   outfile.close();
   infile.close();
   return 0;
}