[RESOLVED] Parsing a string

[steve_rm]

Hello

g++ (GCC) 4.6.2

I have a string that I need parse. The string is sdp information. I am trying to seperate each of the elements into seperate strings. Basically the string would contain some thing like this:

v=0 o=sip_user IN 10230 22472 IP4 NET.CAT.NTBC s=SIP_CALL c=IN IP4 10.10.10.44 m=audio 49152 RTP/AVP 0 8 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000

What is the best method to get the ip address?

I was trying something like this:

char *ip_addr = NULL; 
ip_addr = strstr(sdp_string, "c=") ; 
if(ip_addr ! = NULL) { 
printf("foundline: [%s]", ip_addr) ; 
}

Many thanks for any advice.

[Atheist]

I see no problem in using strstr like you posted, altough if you wish to make use of the c++ standard library theres always the string class.

#include <string>
#include <iostream>

int main(int argc, char **argv)
{
	std::string input("etc etc etc c=127.0.0.1 m=ABC");
	size_t ip_pos = input.find("c=");
	if(std::string::npos == ip_pos)
	{
		std::cout << "Can not find c=" << std::endl;
		return -1;
	}

	ip_pos += 2;

	size_t whitespace_pos = input.find(" ", ip_pos);
	if(std::string::npos == ip_pos)
	{
		std::cout << "No whitespace found, invalid input." << std::endl;
		return -1;
	}

	std::string ip_address = input.substr(ip_pos, whitespace_pos - ip_pos);
	std::cout << "Address: " ip_address << std::endl;
	return 0;
}

If you intend to do alot of string parsing and/or favour more elegant approaches AND you are able to use other libraries, have a look at the Boost regexp classes.