HELP PLEASE - How to convert string to byte array

[cpptutor2000]

Could some C guru help me please? A byte is an unsigned char in C.
How do I convert from a C string to a corresponding byte array. Any
help would be greatly appreciated.

[Joona I Palaste]

cp**********@ya hoo.com scribbled the following:

Could some C guru help me please? A byte is an unsigned char in C.
How do I convert from a C string to a corresponding byte array. Any
help would be greatly appreciated.

You don't need to "convert" it. A C string can be used like a byte
array.

For example:
char *s = "Hello, world!";
char c = s[0]; /* c now contains 'H' */

--
/-- Joona Palaste (pa*****@cc.hel sinki.fi) ------------- Finland --------\
\-------------------------------------------------------- rules! --------/
"Bad things only happen to scoundrels."
- Moominmamma

[Martin Ambuhl]

cp**********@ya hoo.com wrote:

Could some C guru help me please? A byte is an unsigned char in C.
No, 'byte' is a synonym for 'char', which may be either signed or
unsigned. An unsigned byte is an unsigned char. Whether there is any
type that corresponds to, for example, an octet depends upon the
implementation.
How do I convert from a C string to a corresponding byte array. Any
help would be greatly appreciated.

A C string *is* a zero-terminated byte array.

char foo[] = "a string";

foo is a string and a char (or byte) array containing
{'a', ' ', 's', 't', 'r', 'i', 'n', 'g', 0}

[Ari Lukumies]

Martin Ambuhl wrote:

cp**********@ya hoo.com wrote:

Could some C guru help me please? A byte is an unsigned char in C.

No, 'byte' is a synonym for 'char', which may be either signed or
unsigned. An unsigned byte is an unsigned char. Whether there is any
type that corresponds to, for example, an octet depends upon the
implementation.

What? Have I been away too long? I thought that a char is an entity
of value, but not necessarily one that resembles a byte. Maybe
I've missed a standard... :D

-atl-
--
A multiverse is figments of its own creations

[Martin Ambuhl]

Ari Lukumies wrote:

Martin Ambuhl wrote:

cp**********@ya hoo.com wrote:

Could some C guru help me please? A byte is an unsigned char in C.

No, 'byte' is a synonym for 'char', which may be either signed or
unsigned. An unsigned byte is an unsigned char. Whether there is any
type that corresponds to, for example, an octet depends upon the
implementation.

What? Have I been away too long? I thought that a char is an entity
of value, but not necessarily one that resembles a byte. Maybe
I've missed a standard... :D

I have no idea what you think you said. A byte and a char are the same
by definition in C, and has been for 16 years, so you've missed not *a*
standard, but *every* standard.

Here's what a char is (3.1.2.5 in C89)
An object declared as type char is large enough to store any member
of the basic execution character set. If a member of the required
source character set enumerated in $2.2.1 is stored in a char object,
its value is guaranteed to be positive. If other quantities are
stored in a char object, the behavior is implementation-defined: the
values are treated as either signed or nonnegative integers.

Here's what a byte is (1.6 in C89)
* Byte --- the unit of data storage in the execution environment
large enough to hold any member of the basic character set of the
execution environment. It shall be possible to express the address of
each individual byte of an object uniquely. A byte is composed of a
contiguous sequence of bits, the number of which is
implementation-defined. The least significant bit is called the
low-order bit; the most significant bit is called the high-order bit.

and if that's not clear, note from the language for sizeof (3.3.3.4);
The sizeof operator yields the size (in bytes) of its operand, ...
When applied to an operand that has type char , unsigned char , or
signed char , (or a qualified version thereof) the result is 1

[pete]

Ari Lukumies wrote:

Martin Ambuhl wrote:

cp**********@ya hoo.com wrote:

Could some C guru help me please? A byte is an unsigned char in C.

No, 'byte' is a synonym for 'char', which may be either signed or
unsigned. An unsigned byte is an unsigned char.
Whether there is any
type that corresponds to, for example, an octet depends upon the
implementation.

What? Have I been away too long? I thought that a char is an entity
of value, but not necessarily one that resembles a byte. Maybe
I've missed a standard... :D

A byte is a unit of memory.
char is an object type.

--
pete

[Joona I Palaste]

pete <pf*****@mindsp ring.com> scribbled the following:

Ari Lukumies wrote:

Martin Ambuhl wrote:

> cp**********@ya hoo.com wrote:
>> Could some C guru help me please? A byte is an unsigned char in C.
>
> No, 'byte' is a synonym for 'char', which may be either signed or
> unsigned. An unsigned byte is an unsigned char.
> Whether there is any
> type that corresponds to, for example, an octet depends upon the
> implementation.
What? Have I been away too long? I thought that a char is an entity
of value, but not necessarily one that resembles a byte. Maybe
I've missed a standard... :D

A byte is a unit of memory.
char is an object type.

In the context of the C programming language, "byte" and "char" are the
same thing. In other contexts they might be different.

--
/-- Joona Palaste (pa*****@cc.hel sinki.fi) ------------- Finland --------\
\-------------------------------------------------------- rules! --------/
"C++ looks like line noise."
- Fred L. Baube III

[Joe Wright]

Joona I Palaste wrote:

pete <pf*****@mindsp ring.com> scribbled the following:

Ari Lukumies wrote:

Martin Ambuhl wrote:

cp********* *@yahoo.com wrote:

>Could some C guru help me please? A byte is an unsigned char in C.

No, 'byte' is a synonym for 'char', which may be either signed or
unsigned. An unsigned byte is an unsigned char.
Whether there is any
type that corresponds to, for example, an octet depends upon the
implementat ion.

What? Have I been away too long? I thought that a char is an entity
of value, but not necessarily one that resembles a byte. Maybe
I've missed a standard... :D

A byte is a unit of memory.
char is an object type.

In the context of the C programming language, "byte" and "char" are the
same thing. In other contexts they might be different.

I agree. Now if we can get Chris Torek to agree ..

--
Joe Wright mailto:jo****** **@comcast.net
"Everything should be made as simple as possible, but not simpler."
--- Albert Einstein ---

[Richard Bos]

Joe Wright <jo********@com cast.net> wrote:

Joona I Palaste wrote:

pete <pf*****@mindsp ring.com> scribbled the following:

A byte is a unit of memory.
char is an object type.

In the context of the C programming language, "byte" and "char" are the
same thing. In other contexts they might be different.

I agree. Now if we can get Chris Torek to agree ..

Well, if you're being picky, pete is right: char is a basic object type;
a byte is the amount of memory that one object of type char takes.

Richard

[Joe Wright]

Richard Bos wrote:

Joe Wright <jo********@com cast.net> wrote:

Joona I Palaste wrote:

pete <pf*****@mindsp ring.com> scribbled the following:
A byte is a unit of memory.
char is an object type.

In the context of the C programming language, "byte" and "char" are the
same thing. In other contexts they might be different.

I agree. Now if we can get Chris Torek to agree ..

Well, if you're being picky, pete is right: char is a basic object type;
a byte is the amount of memory that one object of type char takes.

Richard

Maybe a difference without a distinction. The term char is a C language
thing and the term byte is more generic, having to do with memory size
and disk size, etc. For most practical purposes the C char type
describes a byte object in memory and on disk. Some might suggest a
difference between a char object and a byte object. I am not one of them.

--
Joe Wright mailto:jo****** **@comcast.net
"Everything should be made as simple as possible, but not simpler."
--- Albert Einstein ---