Code:

    for(int i=0; i<=3; i++){   
            gets(&text[i][0]);
            }
            for(int i=0; i<=3; i++){  
                    for(int j=0; text[i][j]!='\0'; j++){
                            text[i][j] = tolower(text[i][j]);
                            }
                            }
                    for(int i=0; i<=3; i++){ 
                            searchPtr = &text[i][0];
                            while ( searchPtr = strstr( searchPtr, search ) ) {
                            count++;
                            searchPtr++;
                            }
}

can u help me to put a sentinel control on this code using EOF? plz help

the output should be like this

Enter a search string : th

Enter Lines of text :

//even if i enter many lines of text(shoud be limitless), but if i press ctrl + z it should stop loop and it should compute for occurences

plz i need help for this

You can have a sentinel value, or you can read until EOF; you can't do both.

First, you mistyped "getline" as "gets", so you'll want to fix that.

Second, if you want to read until EOF, then you use the result value of getline as your loop control rather than looping from 0 to 3 (which, perhaps inconveniently, is four lines of text, not three). I don't see any reason to store the old lines of text, so unless you have one you shouldn't bother -- just make a string and read into the same string each time.

I mean that i must enter EOF to end the input . . . .

So then there you go. Fix "gets" to "getline" and make that your loop control:

Code:

while (cin.getline(<string>)) {
    <stuff>
}

Originally Posted by tabstop

You can have a sentinel value, or you can read until EOF; you can't do both.

EOF is a sentinel value, assuming use of a method of reading that returns EOF when it reaches end of file.

You could use getline, by keep in mind by default it will just grab 1 line of text, e.g. each input is delimited by the newline character. If you want to input multiple lines and preserve the formatting one option is just to use a loop and input char by char into a std::string. (Note: on windows in order to signal EOF you need to do <enter>ctrl^z<enter>)

Now being C++, you can drop all that C crap and do this using std::strings and the members of the string object to find and count your substring. This should get you going in the right direction:

Code:

#include <iostream>
#include <algorithm>
#include <string>

int main(void){
	
	std::string input;
	int charInput;

	while((charInput=std::getchar())!=EOF)
		input+=charInput;
	
	std::cout <<"\nYou entered: \n\t"<<input;
	
	std::transform(input.begin(),input.end(),input.begin(),::tolower);
	std::cout <<"\nIn lower case: \n\t"<<input;

	/* Use the functions provided by the std::string object to find your
	substring and count your substring*/

	std::cin.get();
	return(0);	
}

Now for a real C++ solution, you would drop the loop all together and just use the stream iterators to grab your input:

Code:

#include <iostream>
#include <algorithm>
#include <iterator>
#include <istream>
#include <string>

int main(void){

	std::cin >> std::noskipws;

	std::istream_iterator<char>start(std::cin);
	std::istream_iterator<char>end;
	std::string input(start,end);

	std::cout<<"You entered:\n\n"<<input;

	std::transform(input.begin(),input.end(),input.begin(),::tolower);

	std::cout<<"\nLower case:\n\n"<<input;

	return(0);
}