471,325 Members | 1,617 Online
Bytes | Software Development & Data Engineering Community
Post +

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 471,325 software developers and data experts.

memcmp and memcpy in c# ?

Hi,

I'm new to c# an missing functions like memcmp and memcpy from C.
Is there something similar ?

cu
Alex

Jan 11 '06 #1
7 12366
Alex,

To copy value types (such as structures) what you need to do is just using
the assignment operator; this will make a shallow copy of the struct
members.

I would say almost all reference types that represent block of data in the
memory (e.g. arrays and collections) CopyTo
method. Actually this method is defined in the ICollection interface.

The other way you can create a copy of an object's data is to call Clone if
the type implements ICloneable interface.

In addition there is a method defined on the level of the Object class
called MemberwiseClone. This mehod creates a shallow copy of the object. The
method is protected and is meant to be used for implementing *clone*.

As far as string comparison goes you can use the CompareXXXX methods of
the String class.

--
HTH
Stoitcho Goutsev (100)

"Alex Stark" <st****@online.nospam> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...
Hi,

I'm new to c# an missing functions like memcmp and memcpy from C.
Is there something similar ?

cu
Alex

Jan 11 '06 #2
Hi Stoicho,

thanks for your answer. But I don't really understand what you mean.
All I have is a bytearray b1 and I want to kow is, if a second bytearray b2
is part somewhere in b1.

In C the code is a simple :

int section_init(uchar *tra, int tralen)
{
int i, j=0;
uchar buf[256];

if (memcmp(tra+4, "LOCKED", 6))
return(0);
...................
}

How is such a simple think in C# realizable ? Sure, I can build a string
and in this case this will be the easiest way.....but I think, there are
some
more complex issues, where string conversation will not the best way.

Thanks for your help !!!!!!!!!!!

Alex
"Stoitcho Goutsev (100)" <10*@100.com> schrieb im Newsbeitrag
news:O6**************@TK2MSFTNGP12.phx.gbl...
Alex,

To copy value types (such as structures) what you need to do is just using
the assignment operator; this will make a shallow copy of the struct
members.

I would say almost all reference types that represent block of data in the
memory (e.g. arrays and collections) CopyTo
method. Actually this method is defined in the ICollection interface.

The other way you can create a copy of an object's data is to call Clone
if the type implements ICloneable interface.

In addition there is a method defined on the level of the Object class
called MemberwiseClone. This mehod creates a shallow copy of the object.
The method is protected and is meant to be used for implementing *clone*.

As far as string comparison goes you can use the CompareXXXX methods of
the String class.

--
HTH
Stoitcho Goutsev (100)

"Alex Stark" <st****@online.nospam> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...
Hi,

I'm new to c# an missing functions like memcmp and memcpy from C.
Is there something similar ?

cu
Alex


Jan 11 '06 #3
"Alex Stark" <st****@online.nospam> wrote in
news:e4**************@TK2MSFTNGP10.phx.gbl:
Hi Stoicho,

thanks for your answer. But I don't really understand what you mean.
All I have is a bytearray b1 and I want to kow is, if a second
bytearray b2 is part somewhere in b1.

In C the code is a simple :

int section_init(uchar *tra, int tralen)
{
int i, j=0;
uchar buf[256];

if (memcmp(tra+4, "LOCKED", 6))
return(0);
..................
}

How is such a simple think in C# realizable ? Sure, I can build a
string and in this case this will be the easiest way.....but I think,
there are some
more complex issues, where string conversation will not the best way.

Thanks for your help !!!!!!!!!!!

Alex
"Stoitcho Goutsev (100)" <10*@100.com> schrieb im Newsbeitrag
news:O6**************@TK2MSFTNGP12.phx.gbl...
Alex,

To copy value types (such as structures) what you need to do is just
using the assignment operator; this will make a shallow copy of the
struct members.

I would say almost all reference types that represent block of data
in the memory (e.g. arrays and collections) CopyTo
method. Actually this method is defined in the ICollection interface.

The other way you can create a copy of an object's data is to call
Clone if the type implements ICloneable interface.

In addition there is a method defined on the level of the Object
class called MemberwiseClone. This mehod creates a shallow copy of
the object. The method is protected and is meant to be used for
implementing *clone*.

As far as string comparison goes you can use the CompareXXXX
methods of the String class.

--
HTH
Stoitcho Goutsev (100)

"Alex Stark" <st****@online.nospam> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...
Hi,

I'm new to c# an missing functions like memcmp and memcpy from C.
Is there something similar ?

cu
Alex




Have a look at the Buffer class.
Jan 11 '06 #4
Alex,

In .NET array of bytes is different than array of chars which is totally
different than strings. Further mode Char is 16 bit where Byte is 8.
If you want to look for a sub string use strings. Otherwise you
need to write your own code for lookup consecutive bytes in a byte array.

There is no equivalent of memcmp in managed framework.

--
HTH
Stoitcho Goutsev (100)

"Alex Stark" <st****@online.nospam> wrote in message
news:e4**************@TK2MSFTNGP10.phx.gbl...
Hi Stoicho,

thanks for your answer. But I don't really understand what you mean.
All I have is a bytearray b1 and I want to kow is, if a second bytearray
b2
is part somewhere in b1.

In C the code is a simple :

int section_init(uchar *tra, int tralen)
{
int i, j=0;
uchar buf[256];

if (memcmp(tra+4, "LOCKED", 6))
return(0);
..................
}

How is such a simple think in C# realizable ? Sure, I can build a string
and in this case this will be the easiest way.....but I think, there are
some
more complex issues, where string conversation will not the best way.

Thanks for your help !!!!!!!!!!!

Alex
"Stoitcho Goutsev (100)" <10*@100.com> schrieb im Newsbeitrag
news:O6**************@TK2MSFTNGP12.phx.gbl...
Alex,

To copy value types (such as structures) what you need to do is just
using the assignment operator; this will make a shallow copy of the
struct members.

I would say almost all reference types that represent block of data in
the memory (e.g. arrays and collections) CopyTo
method. Actually this method is defined in the ICollection interface.

The other way you can create a copy of an object's data is to call Clone
if the type implements ICloneable interface.

In addition there is a method defined on the level of the Object class
called MemberwiseClone. This mehod creates a shallow copy of the object.
The method is protected and is meant to be used for implementing *clone*.

As far as string comparison goes you can use the CompareXXXX methods of
the String class.

--
HTH
Stoitcho Goutsev (100)

"Alex Stark" <st****@online.nospam> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...
Hi,

I'm new to c# an missing functions like memcmp and memcpy from C.
Is there something similar ?

cu
Alex



Jan 11 '06 #5
Stoitcho Goutsev (100) <10*@100.com> wrote:
In .NET array of bytes is different than array of chars which is totally
different than strings. Further mode Char is 16 bit where Byte is 8.
If you want to look for a sub string use strings. Otherwise you
need to write your own code for lookup consecutive bytes in a byte array.

There is no equivalent of memcmp in managed framework.


Note that there's Buffer.BlockCopy, which isn't really an equivalent,
but can sometimes be used in the same situations.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too
Jan 11 '06 #6
Hello Jon Skeet [C# MVP],
Stoitcho Goutsev (100) <10*@100.com> wrote:
In .NET array of bytes is different than array of chars which is
totally
different than strings. Further mode Char is 16 bit where Byte is 8.
If you want to look for a sub string use strings. Otherwise you
need to write your own code for lookup consecutive bytes in a byte
array.
There is no equivalent of memcmp in managed framework.

Note that there's Buffer.BlockCopy, which isn't really an equivalent,
but can sometimes be used in the same situations.


Note that memcmp = memory compare, as he's searching for a byte sequence
in a larger array.
Don't think there's anything present in the .NET framework that does exactly
that, at least neither Buffer or Array seems to have any methods that compare
parts of arrays against each other.

--
Lasse Vågsæther Karlsen
http://usinglvkblog.blogspot.com/
mailto:la***@vkarlsen.no
PGP KeyID: 0x2A42A1C2
Jan 12 '06 #7
Lasse Våqsæther Karlsen wrote:
There is no equivalent of memcmp in managed framework.

Note that there's Buffer.BlockCopy, which isn't really an equivalent,
but can sometimes be used in the same situations.


Note that memcmp = memory compare, as he's searching for a byte sequence
in a larger array.


Oops - you're absolutely right. I misread Stoitcho's post. Doh!

Jon

Jan 12 '06 #8

This discussion thread is closed

Replies have been disabled for this discussion.

Similar topics

16 posts views Thread by rajkumar | last post: by
4 posts views Thread by blueblueblue2005 | last post: by
6 posts views Thread by Sidney Cadot | last post: by
39 posts views Thread by Martin | last post: by
reply views Thread by rosydwin | last post: by

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.