Thread: strcspn & strlen

Ok, I have searched the archives and cannot find an answer to my question, so ... I am tokenizing strings by the delimiter ':' and cannot seem
to assign and index value from the output of the strcspn function. Anyone help?

Also having trouble comparing a strlen output to an integer value, any clue?

Code:

#include <iostream>
#include <cstring>             //for strcpy(), strcat() etc.
using namespace std;
////////////////////////////////////////////////////////////////
class String                    //user-defined string type
{
	protected:
       enum { SZ = 80 };          //size of all String objects
	   char str[SZ];              //holds a C-string
	public:
       String()			          //no-arg constructor
              { str[0] = '\0'; }
	   String( char s[] )         //1-arg constructor
	       { strcpy(str, s); }    //   convert C-string to String
	   void display() const       //display the String
	       { cout << str; }
	   operator char*()           //conversion operator
	       { return str; }        //convert String to C-string
	   String operator + (String s1);
	   bool operator == (String s1);
	   bool operator > (String s1);
	   bool operator < (String s1);
	   bool operator != (String s1);
	   bool operator >= (String s1);
	   bool operator <= (String s1);
};
String String::operator + (String s1)
{
	strcat(str, s1);
	return s1;
}
bool String::operator == (String s1)
{
	 return (strcmp(str, s1)==0 ) ? true : false; 
}
bool String::operator > (String s1)
{
	 return (strcmp(str, s1) > 0 ) ? true : false; 
}
bool String::operator < (String s1)
{
	 return (strcmp(str, s1) < 0 ) ? true : false; 		
}
bool String::operator != (String s1)
{
	 return (strcmp(str, s1) != 0 ) ? true : false; 				
}
bool String::operator >= (String s1)
{
	 return (strcmp(str, s1) >= 0 ) ? true : false; 
}
bool String::operator <= (String s1)
{
	 return (strcmp(str, s1) <= 0 ) ? true : false; 
}
class StringTokenizer : public String
{
	private:
		int index;
		char delimiter;
	public:
		StringTokenizer(String s1, char d) 
			{	
				d = ' ';
			}
		int countToken()
			{	
				int temp;
				temp = strcspn( str , ":" ); //<<<<---- Problems here
				temp++;     //account for the end of the string
				return temp;
			}
		bool hasMoreToken()
			{
				if (index < strlen(str))   //<<<----- And Here!
					return true;
				else 
					return false;
			}
		String nextToken()
			{
				str.erase(0, index);		//erase everything from front of string to index
				int end = str.find(':');	//find the end of the token
				int null = str.find('\0');  //find the end of the string
				str.erase(end, null - 1);	//erase everything from end of token to 1 before null
			}
};

Already spent too many hours trying to figure it out.. Thanks!

Andrew

well we cant figure it out either if u dont give uss the entire code
or at least tell uss how erase() and find() work??!

Code:

void main(void)
{
	String s("dunc0035:!:5701:500::/shome/dunc0035:/bin/ksh");
    StringTokenizer tokens( s, ':' );
}

Heres the rest of the code... It won't help you...

.find(), erase, replace and insert are string objects, how are they relevent to my problems??

Originally posted by pode
well we cant figure it out either if u dont give uss the entire code
or at least tell uss how erase() and find() work??!

I do not see how this comiles at all. str in your String class, and thus your decendant(?!) StringTokenizer is a char[]. I don't see how .find() works here. strcspn() returns the number of characters before ":" not the number of ":"'s The constructor to StringTokenizer ingores all of it's paramiters, and in fact set's one of them to space for no earthly reason, then leaves str as the empty string from the default ctor of String. index is set to just random garbage. NextToken blows away all other tokens (if find and erase work the same way as std::string) and then does not even bother with returning anything.

The only thing I can help you with, without re-writing the whole thing, is strlen. strlen returns a size_t, usually unsigned, make index a size_t or cast away the warning, but that is by far the least of your problems.

That was poorly written, so heck, just use this.

Code:

#include<deque>
#include<string>
#include<iostream>

class tokenizer {
	std::deque<std::string> tokens;
	std::string delm;
	typedef std::string::size_type index_t;
public:
	tokenizer(const std::string &d=" ") : delm(d) {}
	void parse(const std::string &);
	const std::string & top() const {return tokens.front();}
	void pop() { tokens.pop_front(); }
	bool empty() const { return tokens.empty();}
};

void tokenizer::parse(const std::string &s) {
	index_t start=0;
        index_t end;
	do {
		end=s.find_first_of(delm,start);
		tokens.push_back(s.substr(start,end-start));
		start = end+1;
	} while(end != std::string::npos);
}

int main(int argc, char *argv[]) {
	tokenizer t(":");
	if(argc==1) {
		t.parse("dunc0035:!:5701:500::/shome/dunc0035:/bin/ksh");
	} else {
		for(int i=1;i<argc;++i) t.parse(argv[i]);
	}
	while(!t.empty()) {
		std::cout <<'"'<< t.top() <<'"'<< std::endl;
		t.pop();
	}
	return 0;
}

Thanks Cela!