.\" ident @(#)cerr.3
.\" Standard Template Library
.\" $$RW_INSERT_HEADER "slyrs.man"
.TH cerr 3C++ "02 Apr 1998" "Rogue Wave Software" "-"
.ce2
Standard C++ Library   
Copyright 1998, Rogue Wave Software, Inc.   

.SH NAME

\f2cerr\fP

\ - Controls output to an unbuffered stream buffer associated with the object \f2stderr\fP declared in \f2<cstdio>\fP.



.SH  SYNOPSIS


.br
#include <iostream>
.br
extern ostream cerr;
.br
ostream cerr;



.SH  DESCRIPTION


The object \f2cerr\fP controls output to an unbuffered stream buffer associated with the object \f2stderr\fP declared in \f2<cstdio>\fP. By default, the standard C and C++ streams are synchronized, but you can improve performance by using the \f2ios_base\fP member function \f2synch_with_stdio\fP to desynchronize them. 



.SH  FORMATTING


The formatting is done through member functions or manipulators. See \f2cout\fP or \f2basic_ostream\fP for details.



.SH  EXAMPLE



.br
//
.br
// cerr example
.br
//
.br
#include<iostream>
.br
#include<fstream>
.br

.br
void main ( )
.br
{
.RE
.RS 1
using namespace std;
.RE
.RS 0

.RE
.RS 2
// open the file "file_name.txt"
.br
// for reading
.RE
.RS 1
ifstream in("file_name.txt");
.br

.RE
.RS 2
// output the all file to stdout
.RE
.RS 1
if ( in ) 
.RE
.RS 3
cout << in.rdbuf(); 
.RE
.RS 1
else
.RE
.RS 4
// if the ifstream object is in a bad state
.br
// output an error message to stderr
.RE
.RS 3
cerr << "Error while opening the file" << endl; 
.RE
.RS 0
}



.SH  SEE ALSO


basic_ostream(3C++), basic_iostream(3C++), basic_filebuf(3C++), cout(3C++), cin(3C++), clog(3C++), wcin(3C++), wcout(3C++), wcerr(3C++), wclog(3C++), iomanip(3C++), ios_base(3C++), basic_ios(3C++)

Working Paper for Draft Proposed International Standard for Information Systems--Programming Language C++, Section 27.3.1 



.SH  STANDARDS CONFORMANCE


ANSI X3J16/ISO WG21 Joint C++ Committee