Improve company productivity with a Business Account.Sign Up

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 269
  • Last Modified:

GetLine() Question

I am using get line to store a string:

this is an example program:


#include <iostream>
#include <string>
#include <iomanip>

int main()
{
string strName;

cout << "Enter Name: ";
getline (cin, strName);

return 0;
}

the problem is that when I use get line, you have to hit enter twice. What will happen is, I will hit enter it will move to the next line, but I have to hit enter again for input to terminate.


Why is it doing this?

-Brian
0
BrianGEFF719
Asked:
BrianGEFF719
  • 3
  • 2
  • 2
  • +2
2 Solutions
 
MysidiaCommented:
That's rather unusual.. which compiler version/OS environment?
0
 
BrianGEFF719Author Commented:
Visual C++ 6.0
0
 
BrianGEFF719Author Commented:
VC++ 6, Windows XP SP2
0
Upgrade your Question Security!

Your question, your audience. Choose who sees your identity—and your question—with question security.

 
efnCommented:
This is a known bug in this compiler's library.

http://support.microsoft.com/support/kb/articles/Q240/0/15.ASP

http://www.dinkumware.com/vc_fixes.html

It's also documented in a number of PAQs here on Experts Exchange.

--efn
0
 
itsmeandnobodyelseCommented:
On a WinXP VC 6.0 environment happens the same. It is because of that sequence in <string> include file:

        for (; ; _C = _I.rdbuf()->snextc())
            if (_Tr::eq_int_type(_Tr::eof(), _C))
                {_St |= ios_base::eofbit;
                break; }
            else if (_Tr::eq((_E)_C, _D))
                {_Chg = true;
                _I.rdbuf()->snextc();
                break; }
            else if (_X.max_size() <= _X.size())
                {_St |= ios_base::failbit;
                break; }
            else
                _X += _Tr::to_char_type(_C), _Chg = true;

The first 'else if'  truely finds out that the terminating character was entered *but* calls again _I.rdbuf()->snextc(); So you have to hit <Enter> again. I don't know if that is a bug or how to overcome that strange behavior.

Regards, Alex
 
0
 
MysidiaCommented:
It seems to be one of the bugs in the C++ library included with MSVC

See this page:
  http://people.msoe.edu/~taylor/resources/msvc60.htm

the subitem called getline()
apparently you can patch the header files to fix this problem
(be sure to back up any compiler header files to be changed before editing them)
0
 
itsmeandnobodyelseCommented:
@efn

thanks, for the answer. I am going to modify STL header file. Or should i rewrite std::string? ;-)

Regards, Alex
0
 
teratomaCommented:
Have you tried cin.getline?
0
 
MysidiaCommented:
If you want to resort to changing your own code, then you could try the simpler C stdio library
if you like...

#include <iostream>
#include <string>
#include <iomanip>
#include <cstdio>

int main()
{
  string strName;
  char buf[512];

   printf ("Enter name:");

   if ( fgets(buf, sizeof(buf), stdin) ) {
      strName = string(buf);
   } else {
      fprintf(stderr, "Error: unable to read name\n");
      return 1;
  }

  return 0;
}
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

  • 3
  • 2
  • 2
  • +2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now