Why the simple code can not compile?

[Jack]

#include "string.h"
#include <iostream>
using namespace std;
int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;
}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

I tried to compile it on Solaris SUN.

Thanks.

[Barry]

Jack wrote:

#include "string.h"
#include <iostream>
using namespace std;

suppose the function is in some cxx file

void bzero(char*, size_t);

int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;
}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

I tried to compile it on Solaris SUN.

Thanks.

--
Thanks
Barry

[Ian Collins]

Jack wrote:

#include "string.h"
#include <iostream>
using namespace std;
int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;
}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

man bzero (and check the include file).

--
Ian Collins.

[Neelesh Bodas]

On Sep 20, 11:25 am, Jack <[e-mail]:

#include "string.h"
#include <iostream>
using namespace std;
int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;

}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

I tried to compile it on Solaris SUN.

bzero was declared in C header 'strings.h'. I am not sure if C++
header strings.h declares it, but othe point to note is that this
function is deprecated, and it is suggested (by 'man bzero') that
memset be used instead.

Of course I am assuming that you are talking about the bzero function
defined in the (c-standard) library. If you are talking about your
self-defined bzero function, make sure that its prototype is made
available.

Neelesh

-Neelesh

[robertwessel2]

On Sep 20, 1:49 am, Neelesh Bodas <[e-mail]:

bzero was declared in C header 'strings.h'. I am not sure if C++
header strings.h declares it, but othe point to note is that this
function is deprecated, and it is suggested (by 'man bzero') that
memset be used instead.

Of course I am assuming that you are talking about the bzero function
defined in the (c-standard) library. If you are talking about your
self-defined bzero function, make sure that its prototype is made
available.

There is no bzero in the standard C (or C++) library, but it's a
fairly common extension in *nix implementations.

[James Kanze]

On Sep 20, 8:49 am, Neelesh Bodas <[e-mail]:

On Sep 20, 11:25 am, Jack <[e-mail]:

#include "string.h"
#include <iostream>
using namespace std;
int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;
}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

I tried to compile it on Solaris SUN.

bzero was declared in C header 'strings.h'.

Only in certain versions of Unix, pre-1990.

I am not sure if C++
header strings.h declares it, but othe point to note is that this
function is deprecated, and it is suggested (by 'man bzero') that
memset be used instead.

Not deprecated. It never officially existed, at least in
standard C. It was present in the Berkley distributions of
Unix, and is part of Posix, but in the supplementary header
<strings.h(not <string.h>). Given that it's deprecated by
Posix, however, and was never part of standard C, I'd definitely
replace it by memset (which is standard, and declared in
<string.h>---or you can use std::memset, and <cstring>).

--
James Kanze (GABI Software) email:ja*********@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientierter Datenverarbeitung
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[Jack]

On Sep 19, 11:49 pm, Neelesh Bodas <[e-mail]:

On Sep 20, 11:25 am, Jack <[e-mail]:

#include "string.h"
#include <iostream>
using namespace std;
int main()
{
char buf[1024] = "This is a test.";
int len = 1024;
bzero(buf, len);
cout<<"buf::"<<buf<<endl;

}

The error is:
line 8: Error: The function "bzero" must have a prototype.
1 Error(s) detected.

I tried to compile it on Solaris SUN.

bzero was declared in C header 'strings.h'. I am not sure if C++
header strings.h declares it, but othe point to note is that this
function is deprecated, and it is suggested (by 'man bzero') that
memset be used instead.

Of course I am assuming that you are talking about the bzero function
defined in the (c-standard) library. If you are talking about your
self-defined bzero function, make sure that its prototype is made
available.

Neelesh

-Neelesh

Thanks. But it works fine on Linux when I used g++. And it is defined
in <string.hon Linux.

[werasm]

James Kanze wrote:

Not deprecated. It never officially existed, at least in
standard C. It was present in the Berkley distributions of
Unix, and is part of Posix, but in the supplementary header
<strings.h(not <string.h>). Given that it's deprecated by
Posix, however, and was never part of standard C, I'd definitely
replace it by memset (which is standard, and declared in
<string.h>---or you can use std::memset, and <cstring>).

Maybe I'm slightly paranoid, but I would rather use something
like this...

#include <cstddef>
#include <algorithm>

template <class T, std::size_t N>
void zero( T(&array)[N] )
{
std::fill( array, array+N, T() );
}

int main()
{
char array[] = "Hallo";
zero( array );
}

.... as I've seen memset being used erroneously by mistake
one to many times. OTOH I think you would probably too.

Regards,

Werner

[James Kanze]

On Sep 20, 6:34 pm, werasm <[e-mail]:

James Kanze wrote:

Not deprecated. It never officially existed, at least in
standard C. It was present in the Berkley distributions of
Unix, and is part of Posix, but in the supplementary header
<strings.h(not <string.h>). Given that it's deprecated by
Posix, however, and was never part of standard C, I'd definitely
replace it by memset (which is standard, and declared in
<string.h>---or you can use std::memset, and <cstring>).

Maybe I'm slightly paranoid, but I would rather use something
like this...

Not paranoid, just good programming practice.

#include <cstddef>
#include <algorithm>

template <class T, std::size_t N>
void zero( T(&array)[N] )
{
std::fill( array, array+N, T() );
}

int main()
{
char array[] = "Hallo";
zero( array );
}

... as I've seen memset being used erroneously by mistake
one to many times. OTOH I think you would probably too.

Now that you mention it, yes. Memset only works for C style
arrays of integers. std::fill (and std::fill_n) works for
everything. (And in C, it was a common error to see memset used
for arrays of double or of pointer.)

--
James Kanze (GABI Software) email:ja*********@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientierter Datenverarbeitung
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[Jerry Coffin]

In article <11**********************@22g2000hsm.googlegroups. com>,
ja*********@gmail.com says...

[ ... ]

Now that you mention it, yes. Memset only works for C style
arrays of integers.

It works for arrays of char. For arrays of integers, it works only for a
rather loose definition of "works". Generally speaking, the only value
that's useful for non-char types is zero. For example:

int x;

memset(&x, 1, sizeof(x));

std::cout << x;

One likely result:

16843009

--
Later,
Jerry.

The universe is a figment of its own imagination.