STL string - converting to low case

[Vadim]

Hi!

I have a STL string, which I need to convert to low case.
In VC 6 I used:
string sInputBuffer = _strlwr((char*) sBuffer.c_str() );

However, now in MSVC.NET 2005 I am getting a warning, that _strlwr is
depricated. Instead, it's proposed to use _strlwr_s :
http://msdn2.microsoft.com/en-us/library/y889wzfw.aspx

How should I use this new function with STL, if I don't want to
allocate memory on heap.

Thanks.

Vadim

[int2str]

Vadim wrote:

Hi!

I have a STL string, which I need to convert to low case.
In VC 6 I used:
string sInputBuffer = _strlwr((char*) sBuffer.c_str() );

Try this maybe (std C++ - don't know about MVC):

std::transform( sBuffer.begin() , sBuffer.end(), sBuffer.begin() ,
::tolower );

Cheers,
Andre

[roberts.noah]

Vadim wrote:

Hi!

I have a STL string, which I need to convert to low case.
In VC 6 I used:
string sInputBuffer = _strlwr((char*) sBuffer.c_str() );

However, now in MSVC.NET 2005 I am getting a warning, that _strlwr is
depricated. Instead, it's proposed to use _strlwr_s :
http://msdn2.microsoft.com/en-us/library/y889wzfw.aspx

How should I use this new function with STL, if I don't want to
allocate memory on heap.

Are you sure you need to convert to lower case? If all you want is
case insensitive comparison you might have a look at char_traits.

[Victor Bazarov]

Vadim wrote:

I have a STL string, which I need to convert to low case.
In VC 6 I used:
string sInputBuffer = _strlwr((char*) sBuffer.c_str() );
Ugh!
However, now in MSVC.NET 2005 I am getting a warning, that _strlwr is
depricated. Instead, it's proposed to use _strlwr_s :
http://msdn2.microsoft.com/en-us/library/y889wzfw.aspx

How should I use this new function with STL, if I don't want to
allocate memory on heap.

http://groups.google.com/groups?q=co...se&qt_s=Search

V

[E. Mark Ping]

In article <11************ *********@g14g2 000cwa.googlegr oups.com>,
Vadim <va*******@gmai l.com> wrote:

string sInputBuffer = _strlwr((char*) sBuffer.c_str() );

Ouch. I suggest you look up the definition of _strlwr.

Also, note that c_str() returns a non-modifiable c-style string.
--
Mark Ping
em****@soda.CSU A.Berkeley.EDU

[atgraham]

Try this:

struct lowercase_func {
void operator()(std: :string::value_ type& v) { v = tolower(v); }
};
std::string make_lowercase( std::string s) {
for_each(s.begi n(), s.end(), lowercase_func( ));
return s;
}

[Richard Herring]

In message <11************ **********@g49g 2000cwa.googleg roups.com>,
at******@gmail. com writes

Try this:

struct lowercase_func {
void operator()(std: :string::value_ type& v) { v = tolower(v); }
};
std::string make_lowercase( std::string s) {
for_each(s.begi n(), s.end(), lowercase_func( ));
return s;
}

But for_each is intended to be a non-modifying operation. OK, it will
work, but std::transform( s.begin(), s.end(), s.begin(), tolower) would
more clearly express your intention.

--
Richard Herring

[Earl Purple]

ro**********@gm ail.com wrote:

Are you sure you need to convert to lower case? If all you want is
case insensitive comparison you might have a look at char_traits.

and exactly which function of char_traits would you use to do that?

[Vadim]

Thanks for your help.
In fact, I do need to make some case insensitive finds, but since some
parts of my original string I will have to convert later to unified
case, I decieded to convert the original string to low case. It seems
that there is no any perfoamnce problem. 250 Kb file in my string is
converted to low case almost without seeing delay in "Step over"
debugging.

I do have perfomance problem with reading from file and I guess you can
help me:
I have a text file, which I read entirely to my string variable.
Originally I made some checks while reading, so my code looks like
that:

ifstream is;
is.open (INPUT_FILE);
string sInputBuffer;

while (is.good())
{
sInputBuffer+= is.get();
}

Now, I just only read the contents of the file to string buffer.
Reading char after char is definitely the bad thing. What would be the
most efficient way of reading the whole file?

Thanks a lot!

Vadim

[atgraham]

> >

struct lowercase_func {
void operator()(std: :string::value_ type& v) { v = tolower(v); }
};
std::string make_lowercase( std::string s) {
for_each(s.begi n(), s.end(), lowercase_func( ));
return s;
}

But for_each is intended to be a non-modifying operation. OK, it will
work, but std::transform( s.begin(), s.end(), s.begin(), tolower) would
more clearly express your intention.

You're right, std::transform should probably be used instead. However
(you may already know this) the direct usage of tolower is not
portable. See the discussion at:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11108

Aaron