Let's say I have a cstring: char str[] = "Hello world";
and I have a needle: char n[] = "wo";
I find that the needle starts at the 5+1 position of the string.
How am I going to copy the characters up to this point, using the
<cstringheade r?
--
Using <string(c++ string) it is possible in two ways:
1) for (int counter = 0; i < str.find(n); i++)
tmp += str[i];
2) str.substr();
8  2590 
Alexandros H. Halatsis wrote:
Let's say I have a cstring: char str[] = "Hello world";
and I have a needle: char n[] = "wo";
I find that the needle starts at the 5+1 position of the string.
You do? How?
How am I going to copy the characters up to this point, using the
<cstringheade r?
RTFM about 'strncpy' function.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
On Oct 29, 5:59 pm, "Victor Bazarov" <v.Abaza...@com Acast.netwrote:
Alexandros H. Halatsis wrote:
Let's say I have a cstring: char str[] = "Hello world";
and I have a needle: char n[] = "wo";
I find that the needle starts at the 5+1 position of the string.
You do? How?
How am I going to copy the characters up to this point, using the
<cstringheade r?
RTFM about 'strncpy' function.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Propably it's my fault for not clarifying enough my problem. User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
AFAIK strncpy requires number of characters to copy, but I don't know
the number. Now what?
Alexandros H. Halatsis wrote:
Propably it's my fault for not clarifying enough my problem. User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
AFAIK strncpy requires number of characters to copy, but I don't know
the number. Now what?
If 'str' is a char * pointing to the first character of your string, and
'needle' is a char * pointing to the first character of the needle
within that string, then 'needle - str' will give you the number you need.
What are you trying to do? Why are you using C-strings and not
C++-strings? Have you considered what will happen if your needle is not
in the string to be searched?
Phil
On 29 Ott, 17:37, "Alexandros H. Halatsis" <stream...@gmai l.com>
wrote:
On Oct 29, 5:59 pm, "Victor Bazarov" <v.Abaza...@com Acast.netwrote:
Alexandros H. Halatsis wrote:
Let's say I have a cstring: char str[] = "Hello world";
and I have a needle: char n[] = "wo";
I find that the needle starts at the 5+1 position of the string.
You do? How?
How am I going to copy the characters up to this point, using the
<cstringheade r?
RTFM about 'strncpy' function.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Propably it's my fault for not clarifying enough my problem. User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
AFAIK strncpy requires number of characters to copy, but I don't know
the number. Now what?
char* str = "hello world";
char* n = "wo";
char* p = std::strstr(str , n);
std::string s;
if (p != NULL)
s = p;
On Oct 29, 7:01 pm, Philip Potter <p...@see.sig.i nvalidwrote:
Alexandros H. Halatsis wrote:
Propably it's my fault for not clarifying enough my problem. User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
AFAIK strncpy requires number of characters to copy, but I don't know
the number. Now what?
If 'str' is a char * pointing to the first character of your string, and
'needle' is a char * pointing to the first character of the needle
within that string, then 'needle - str' will give you the number you need.
What are you trying to do? Why are you using C-strings and not
C++-strings? Have you considered what will happen if your needle is not
in the string to be searched?
Phil
Thanks for the reply. I 'll test it ASAP and report back results.
I 've done it already with C++-strings and I know how to do it.
I 'm doing it now with C-string to get familiar with the c string
functions.
I am sure the needle will be in the string. :-)
On Oct 29, 7:01 pm, Philip Potter <p...@see.sig.i nvalidwrote:
Alexandros H. Halatsis wrote:
Propably it's my fault for not clarifying enough my problem. User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
AFAIK strncpy requires number of characters to copy, but I don't know
the number. Now what?
If 'str' is a char * pointing to the first character of your string, and
'needle' is a char * pointing to the first character of the needle
within that string, then 'needle - str' will give you the number you need.
What are you trying to do? Why are you using C-strings and not
C++-strings? Have you considered what will happen if your needle is not
in the string to be searched?
Phil
Thanks for the reply. I 'll test it ASAP and report back results.
I 've done it already with C++-strings and I know how to do it.
I 'm doing it now with C-string to get familiar with the c string
functions.
I am sure the needle will be in the string. :-)
Alexandros H. Halatsis wrote:
I 've done it already with C++-strings and I know how to do it.
I 'm doing it now with C-string to get familiar with the c string
functions.
A worthy goal. In "real" code (as opposed to "learning" code) I wouldn't
advise using c-strings in C++ at all.
I am sure the needle will be in the string. :-)
A wise programmer knows what can't happen, and guards against it anyway.
I have had problems before when something I was sure "can't happen" did
actually happen, and because I hadn't had guard code to protect myself
the errors were bizarre and didn't occur at the point in the code where
the problem was.
Phil
On 29 Oct, 17:25, "Alexandros H. Halatsis" <stream...@gmai l.com>
wrote:
On Oct 29, 7:01 pm, Philip Potter <p...@see.sig.i nvalidwrote:
Alexandros H. Halatsis wrote:
User
inputs the needle and the string. Let xtetxallnttxxx be the string and
txxx be the needle. Using strstr I get a pointer pointing to the start
of the needle. How am I going to copy the characters up to there?
<snip>
I am sure the needle will be in the string. :-)
put an assert() in then
--
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