Search for string, print line

[tcdnewb]

Hi guys

I'm trying to write a code that searches a file for a string from the command line line-by-line and prints each line with the string.

I have this at the moment

#include <iostream>
#include <fstream>
#include <string>
	 
using namespace std;
	 
	 
int main(int argc, char *argv[])
{
	
	ifstream input;
	char buffer[200];
	bool finished;
	string s;
	
	input.open ( argv[1] );
	
	finished = false;
	
	cout << "LINE2" << endl;
	
	while ( ! finished )
	{
	  input.getline (buffer, 200 );
	  if ( input.eof () )
	    finished = true;
	  else
	    cout << buffer << endl;
	}
	
	
	input.close();
	
	input.open ( argv[1] );
	finished = false;
	
	cout << endl << "LINE" << endl;
	
	while ( ! finished )
	{
	  input >> s;
	  if ( input.eof () )
	    finished = true;
	  else
	    cout << s << endl;
	}
	
	return 0;
}
	

I'm not sure where to put the location of the text file I want to search, or if that should be defined from the command line?

Also I'm not sure how to run the program successfully, if i type a.out I get nothing and cannot type anything.

What I would like is to be able to compile the code, type the string I want to find ( and file I'm searching??) and run it, and have the program print each line with my string.

Thanks for any help!

[tcdnewb]

anyone??

[Dy7SLyTq]

#include <iostream>
#include <fstream>
#include <string>
#include <cstring>

using std::cout;
using std::cerr;
using std::string;
using std::endl
//... all of the others

int main(int argc, char *argv[])
{
	if(argc != 2)
		cerr<<"error: usage: "<< argc[0] <<" <file> <expression>"<< endl;

	else
	{
		ifstream file;

		file.open(argv[1]);

		if(!file.good())
			cerr<<"error: invalid file: "<< argv[1] << endl;

		else
		{
			string line;

			while(getline(file, line))
				if(strcmp(line.c_str(), argv[2])
					cout<< line << endl;
		}
	}
}

[vlad from moscow]

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>


int main(int argc, char *argv[])
{
	if ( argc != 3 )
	{
		std::cerr << "Error. Usage: "<< argv[0] << " <file> <string>" <<  std::endl;
		std::exit( 1 );
	}

	ifstream file( argv[1] );

	if (!file )
	{
		std::cerr << "Error. Invalid file name: " << argv[1] << std::endl;
		std::exit( 2 );
	}

	std::string line;

	while ( std::getline( file, line ) )
	{
		if ( line.find( argv[2] ) != std::string::npos )
		{
			std::cout << line << std::endl;
		}
	}

	return 0;
}