// grabline - get's a line from a text file where first n chars match pattern
// written jan 05 by warren myers for joe myers

using namespace std;
#include <iostream>
#include <fstream>
#include <string>
#include <cstdio>

int main(int argc, char** argv){
	unsigned int match = 0, skip = 0;
	int kt = 0;
	string pat, fle, cmd, out, line, mt, pad;
	char ln[25555];
	ofstream ofle;
	if(argc>1){
		skip = atoi(argv[1]);
	}
	else{
		cout << "How many characters to skip? ";
		cin >> skip;
	}
	if(argc>2){
		mt = argv[2];
	}
	else{
		cout << "Enter what you want to find: ";
		cin >> mt;
	}
	match = mt.length();
	if(argc>3){
		pat = argv[3];
	}
	else{
		cout << "Enter file pattern: ";
		cin >> pat;
	}
	if(argc>4){
		out = argv[4];
	}
	else{
		cout << "Enter file to put results in: ";
		cin >> out;
	}
	cout << "Working...\n";
	ofle.open(out.c_str());
	if(!ofle.good()){
		cout << "Cannot create output file: " << out << ". Bailing.\n";
		return 1;
	}
	pad=""; kt=0;
	while(kt<(match+skip+1)){
		pad += " "; kt++;
	}
	cmd = "dir /b " + pat + " > grabline.in";
	system(cmd.c_str());
	ifstream ifle("grabline.in");
	if(!ifle.good()){
		cout << "Couldn't make grabline.in with file results. Bailing.\n";
		return 1;
	}
	ifstream chk;
	while(!ifle.eof()){
		pat = fle;
		ifle.getline(ln,260);  // next file name
		fle = ln;
		if(fle == pat)
			break;
		if(!fle.length())
			continue;
		chk.open(fle.c_str());
		if(!chk.good()){
			cout << "Couldn't open: " << fle << endl;
		}
		else{
			kt=0;
			while(!chk.eof()){
				chk.getline(ln,25550);
				line = ln + pad;
				kt++;
				if(line.substr(skip,match) == mt){
					ofle << "in file: " << fle
						<< " at line: " << kt
						<< " *\t" << line.substr(skip) << "\n";
				}
			}
		}
		chk.close();
	}
	ifle.close();
	ofle.close();
	ifle.open(out.c_str());
	if(ifle.good()){
		cout << "Results of search:\n\n";
		while(!ifle.eof()){
			ifle.getline(ln,25550);
			cout << ln << endl;
		}
	}
	cout << "Done. Please press a key to end...\n";
	getchar();
	return 0;
}