How to parse comma delimited string?

[ChuckB]

Hi,
I can read a comma delimited file and load the data into a string one line at a time. So, I can get something like...

string s;
s = "12.3, 14.5, 16.7";

I can iterate through the string using s.substr and a 'for' loop...is there an equivalent to 'instr' command as in basic?

Regards,
ChuckB

[Zaei]

std::string::find().

Z.

[Zaei]

Though I believe that the boost library (http://www.boost.org/ ) has a handy string_tokenizer class that will do that work for you =).

Z.

[ChuckB]

Z,
Thanks for the link. They have a lot of samples using iterators...which is what I needed to see. Are you holding out on some other real usefull C++ sites? :-)
Regards,
ChuckB

[jim mcnamara]

Don't overlook strtok() for char * -

#include <stdio.h>
#include <string.h>

int main(){
	char *whatever=
	"this is an, example, showing parsing using, commas and spaces.";
	char *p;
	p=strtok(whatever,", "); /* find the first space */
        while(p){
            printf("%s\n",p);
	    p=strtok('\0'," ,"); /* use spaces & commas*/
        }
   	return 0;
}

[parksie]

Just be bloody careful with where you point strtok -- it changes the string you pass in.

Also, I don't think you can use strtok simultaneously on multiple strings.

[CornedBee]

strtok doesn't change the string, but you can't use it on more than one string, that's right. And it is not thread-safe.

[jim mcnamara]

strtok behaves differently on different boxes. Parksie is right - on HP UX 11.0, for example, it does change the source string.

strtok_r uses a third argument - a char* - that stops strtok from clobbering the source.

In MSVC++ it does not hurt the source.

[parksie]

Quick aside for anyone else... the "_r" means "reentrant", which basically says that it's possible to call the function twice in the same process, at the same time (such as multiple threads). Reentrant functions don't have any static data, or anything like that.

Well, they could. But they don't cause massive lossage if you do it

[CornedBee]

Another side note: the strtok of MSVC++ in the dynamic or multithreaded static CRT library is thread-safe.