sprintf causing segmantation fault

[Saurabh]

Hi all,

I am working on RedHat Linux GCC 3.0.
I am trying to convert a long to string through sprintf.
but i m getting segmantation fault.
I tried snprintf also but no avail.here is the piece of code..

----------------------------
long myLong=200000;
char myStr[50];
memset[myStr,'\0',50];
sprintf(myStr,"%s",myLong);

-------------------------------------

This sprintf causes segmentation fault.

Hoping for help.

Saurabh

[Ian Collins]

Saurabh wrote:

Hi all,

I am working on RedHat Linux GCC 3.0.
I am trying to convert a long to string through sprintf.
but i m getting segmantation fault.
I tried snprintf also but no avail.here is the piece of code..

----------------------------
long myLong=200000;
char myStr[50];
memset[myStr,'\0',50];
sprintf(myStr,"%s",myLong);

^
%s is for printing (C style) strings.

use %ld, or use iostreams.

--
Ian Collins.

[Saurabh]

Ian Collins wrote:

Saurabh wrote:

Hi all,

I am working on RedHat Linux GCC 3.0.
I am trying to convert a long to string through sprintf.
but i m getting segmantation fault.
I tried snprintf also but no avail.here is the piece of code..

----------------------------
long myLong=200000;
char myStr[50];
memset[myStr,'\0',50];
sprintf(myStr,"%s",myLong);

^
%s is for printing (C style) strings.

use %ld, or use iostreams.

--
Ian Collins.

hi Ian,
Thanks a lot.
You solved my problem.
actually I thought that the second argument to
sprintf() refers to the format you wish to convert
to,instead it refers to the format you wish to
convert from.
anyways..
thanks again.
saurabh

[Geo]

Saurabh wrote:

Ian Collins wrote:

Saurabh wrote:

Hi all,

I am working on RedHat Linux GCC 3.0.
I am trying to convert a long to string through sprintf.
but i m getting segmantation fault.
I tried snprintf also but no avail.here is the piece of code..

----------------------------
long myLong=200000;
char myStr[50];
memset[myStr,'\0',50];
sprintf(myStr,"%s",myLong);

^
%s is for printing (C style) strings.

use %ld, or use iostreams.

--
Ian Collins.

hi Ian,
Thanks a lot.
You solved my problem.
actually I thought that the second argument to
sprintf() refers to the format you wish to convert
to,instead it refers to the format you wish to
convert from.
anyways..
thanks again.
saurabh

I would suggest that if you are STILL using sprinf, then you haven't
fixed the problem, it will surely break one day. Why not use
boost::lexical_cast (or you're own similar code) instead.

[Saurabh]

Geo wrote:

Saurabh wrote:

Ian Collins wrote:

Saurabh wrote:
> Hi all,
>
> I am working on RedHat Linux GCC 3.0.
> I am trying to convert a long to string through sprintf.
> but i m getting segmantation fault.
> I tried snprintf also but no avail.here is the piece of code..
>
> ----------------------------
> long myLong=200000;
> char myStr[50];
> memset[myStr,'\0',50];
> sprintf(myStr,"%s",myLong);
^
%s is for printing (C style) strings.

use %ld, or use iostreams.

--
Ian Collins.

hi Ian,
Thanks a lot.
You solved my problem.
actually I thought that the second argument to
sprintf() refers to the format you wish to convert
to,instead it refers to the format you wish to
convert from.
anyways..
thanks again.
saurabh

I would suggest that if you are STILL using sprinf, then you haven't
fixed the problem, it will surely break one day. Why not use
boost::lexical_cast (or you're own similar code) instead.

hi Geo,
I have never used boost::lexical_cast.Is this an STL component?
or are you hinting me to write my own version of sprintf()?

Thanks & Regards
saurabh

[Geo]

Saurabh wrote:

Geo wrote:

Saurabh wrote:

Ian Collins wrote:
> Saurabh wrote:
> > Hi all,
> >
> > I am working on RedHat Linux GCC 3.0.
> > I am trying to convert a long to string through sprintf.
> > but i m getting segmantation fault.
> > I tried snprintf also but no avail.here is the piece of code..
> >
> > ----------------------------
> > long myLong=200000;
> > char myStr[50];
> > memset[myStr,'\0',50];
> > sprintf(myStr,"%s",myLong);
> ^
> %s is for printing (C style) strings.
>
> use %ld, or use iostreams.
>
> --
> Ian Collins.

hi Ian,
Thanks a lot.
You solved my problem.
actually I thought that the second argument to
sprintf() refers to the format you wish to convert
to,instead it refers to the format you wish to
convert from.
anyways..
thanks again.
saurabh

I would suggest that if you are STILL using sprinf, then you haven't
fixed the problem, it will surely break one day. Why not use
boost::lexical_cast (or you're own similar code) instead.

hi Geo,
I have never used boost::lexical_cast.Is this an STL component?
or are you hinting me to write my own version of sprintf()?

Thanks & Regards
saurabh

Hi,

No I was suggesting you write you're own lexical cast function, if you
can't use boost. You could start with something like this, you may want
to make this more robust,

template<typename out, typename in> out lexical_cast(const in &i)
{
std::stringstream ss;
ss << i;
out temp;
ss >> temp;
return temp;
}
then do

int x = 123;
std::string s = lexical_cast<std::string>(x);

you can also do the reverse

std::string s = "5678";
int z = lexical_cast<int>(s);

[Old Wolf]

Saurabh wrote:

memset[myStr,'\0',50];

Take this line out of your code.

[Prawit Chaivong]

Old Wolf wrote:

Saurabh wrote:

memset[myStr,'\0',50];

Take this line out of your code.

Yep, Agree.
And use %d instead of %s.It makes your program think that your 'MyLong'
as a pointer to characters.

[Earl Purple]

Saurabh wrote:

I have never used boost::lexical_cast.Is this an STL component?
or are you hinting me to write my own version of sprintf()?

Thanks & Regards
saurabh

I would not suggest boost::lexical_cast here. The boost equivalent of
sprintf is boost::format.

lexical_cast is useful for converting the other way, i.e. string to
integer.

[Noclambulist]

Geo wrote:

Saurabh wrote:

Geo wrote:

Saurabh wrote:
> Ian Collins wrote:
> > Saurabh wrote:
> > > Hi all,
> > >
> > > I am working on RedHat Linux GCC 3.0.
> > > I am trying to convert a long to string through sprintf.
> > > but i m getting segmantation fault.
> > > I tried snprintf also but no avail.here is the piece of code..
> > >
> > > ----------------------------
> > > long myLong=200000;
> > > char myStr[50];
> > > memset[myStr,'\0',50];
> > > sprintf(myStr,"%s",myLong);
> > ^
> > %s is for printing (C style) strings.
> >
> > use %ld, or use iostreams.
> >
> > --
> > Ian Collins.
>
> hi Ian,
> Thanks a lot.
> You solved my problem.
> actually I thought that the second argument to
> sprintf() refers to the format you wish to convert
> to,instead it refers to the format you wish to
> convert from.
> anyways..
> thanks again.
> saurabh
I would suggest that if you are STILL using sprinf, then you haven't
fixed the problem, it will surely break one day. Why not use
boost::lexical_cast (or you're own similar code) instead.
hi Geo,
I have never used boost::lexical_cast.Is this an STL component?
or are you hinting me to write my own version of sprintf()?

Thanks & Regards
saurabh

Hi,

No I was suggesting you write you're own lexical cast function, if you
can't use boost. You could start with something like this, you may want
to make this more robust,

template<typename out, typename in> out lexical_cast(const in &i)
{
std::stringstream ss;
ss << i;
out temp;
ss >> temp;
return temp;
}

but g++ told me that:
In function `out lexical_cast(const in&) [with out = std::string, in =
int]':
instantiated from here
error: `ss' has incomplete type
error: storage size of `ss' isn't known
then do

int x = 123;
std::string s = lexical_cast<std::string>(x);

you can also do the reverse

std::string s = "5678";
int z = lexical_cast<int>(s);

[Marcus Kwok]

Noclambulist <No**********@gmail.com> wrote:

Geo wrote:

No I was suggesting you write you're own lexical cast function, if you
can't use boost. You could start with something like this, you may want
to make this more robust,

template<typename out, typename in> out lexical_cast(const in &i)
{
std::stringstream ss;
ss << i;
out temp;
ss >> temp;
return temp;
}

but g++ told me that:
In function `out lexical_cast(const in&) [with out = std::string, in =
int]':
instantiated from here
error: `ss' has incomplete type
error: storage size of `ss' isn't known

You need #include <sstream> for std::stringstream.

--
Marcus Kwok
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