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

.SH NAME

\f2cin\fP

\ - Controls input from a stream buffer associated with the object \f2stdin\fP declared in \f2<cstdio>\fP.\f2\fP



.SH  SYNOPSIS


.br
#include <iostream>
.br
extern istream cin;
.br
istream cin;



.SH  DESCRIPTION


The object \f2cin\fP controls input from a stream buffer associated with the object \f2stdin\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.

After the object \f2cin\fP is initialized, \f2cin.tie()\fP returns \f2&cout\fP, which implies that \f2cin\fP and \f2cout\fP are synchronized. 



.SH  EXAMPLE



.br
//
.br
// cin example #1
.br
//
.br
#include <iostream>
.br

.br
void main ( )
.br
{
.RE
.RS 1
using namespace std;
.RE
.RS 3

.RE
.RS 1
int i;
.br
float f;
.br
char c;
.RE
.RS 0

.RE
.RS 2
//read an integer, a float and a character from stdin 
.RE
.RS 1
cin >> i >> f >> c;
.RE
.RS 0

.RE
.RS 2
// output i, f and c to stdout
.RE
.RS 1
cout << i << endl << f << endl << c << endl;   
.RE
.RS 0
}
.br

.br
//
.br
// cin example #2
.br
//
.br
#include <iostream>
.br

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

.RE
.RS 1
char p[50];
.RE
.RS 0

.RE
.RS 2
// remove all the white spaces 
.RE
.RS 1
cin >> ws;
.RE
.RS 0

.RE
.RS 2
// read characters from stdin until a newline
.br
// or 49 characters have been read
.RE
.RS 1
cin.getline(p,50);
.RE
.RS 0

.RE
.RS 2
// output the result to stdout
.RE
.RS 1
cout << p;   
.RE
.RS 0
}

When inputting \f2"  Grendel the monster" (newline)\fP in the previous test, the output is \f2"Grendel the monster"\fP. The manipulator \f2ws\fP removes spaces.



.SH  SEE ALSO


basic_istream(3C++), basic_iostream(3C++), basic_filebuf(3C++), cout(3C++), cerr(3C++), clog(3C++), wcin(3C++), wcout(3C++), wcerr(3C++), wclog(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