std::basic_ostream::write(3)

NAME
std::basic_ostream::write - std::basic_ostream::write

Synopsis
   basic_ostream& write( const char_type* s, std::streamsize count );
   Behaves as an UnformattedOutputFunction. After constructing and checking the sentry
   object, outputs the characters from successive locations in the character array
   whose first element is pointed to by s. Characters are inserted into the output
   sequence until one of the following occurs:
     * exactly count characters are inserted
     * inserting into the output sequence fails (in which case setstate(badbit) is
       called).

Parameters
   s - pointer to the character string to write
   count - number of characters to write

Return value
   *this

Exceptions
   failure if an error occurred (the error state flag is not goodbit) and exceptions()
   is set to throw for that state.
   If an internal operation throws an exception, it is caught and badbit is set. If
   exceptions() is set for badbit, the exception is rethrown.

Notes
   This function is not overloaded for the types signed char or unsigned char, unlike
   the formatted operator<<.
   Also, unlike the formatted output functions, this function does not set the failbit
   on failure.
   When using a non-converting locale (the default locale is non-converting), the
   overrider of this function in std::basic_ofstream may be optimized for zero-copy
   bulk I/O (by means of overriding std::streambuf::xsputn).

Example
   This function may be used to output object representations, i.e. binary output // Run this code
 #include <iostream>
 int main()
 {
     int n = 0x41424344;
     std::cout.write(reinterpret_cast<char*>(&n), sizeof n) << '\n';
     char c[] = "This is sample text.";
     std::cout.write(c, 4).write("!\n", 2);
 }

Possible output:
 DCBA
 This!

See also
   operator<<(std::basic_ostream) inserts character data or insert into rvalue stream
                        (function template)
   put inserts a character
                        (public member function)