Dynamic memory help (array of char)

[fratello]

General Purpose: Delete all "white spaces" in text file, until the read-in char is _not_ a whitespace (mark as start of text file).

Problem: Cannot seem to shift char's over properly. (I think my problem is the inner loop - however other code may lead to this problem - I do not know)

Code:

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

bool trimWhiteSpace(fstream &file, char * charMemoryBlock) {
	if (!file.is_open()) {
		return false;
	}
	streampos posInFile = file.tellg();
	int fileSize = posInFile;
	file.seekg(0, ios::beg);
	file.read(charMemoryBlock, posInFile);
	for (int i = 0; i < fileSize; i++) {
		if (isspace(charMemoryBlock[i])) {
			fileSize--;
			// ?
			for (int j = i; j < fileSize; j++) {
				charMemoryBlock[j] = charMemoryBlock[j + 1];
			}
			// ?
		} else {
			cout << "Trim White Space = COMPLETE, i = " << i << endl;
			cout << "Char value exited on = " << charMemoryBlock[i] << endl;
			return true;
		}
	}
}

int main () {
	fstream file("foo.txt", ios::in | ios::binary | ios::ate);
	char * memblock = new char[file.tellg()];
	trimWhiteSpace(file, memblock);
	file.close();
	// Test the output, to see if whitespaces are deleted
	for (int i = 0; i < 15; i++) {
		cout << memblock[i];
	}
	delete [] memblock;
	return 0;
}

[JLBorges]

#include <fstream>

int main()
{
    std::ifstream file( "foo.txt" ) ;

    char c ;
    if( file >> c ) file.putback(c) ; // read and put back the first non-ws character

    // copy everything from the first non-ws character onwards to foo.trimmed.txt
    std::ofstream ( "foo.trimmed.txt" ) << file.rdbuf() ;    
}

[fratello]

Wow Thanks a lot JLBorges, the more you know!

Also; any simple command in fstream library to put the file into the dynamic char array?

Cheers,
-fratello

[JLBorges]

#include <fstream>
#include <string>
#include <iterator>
#include <iostream>

int main()
{
    std::ifstream file( "foo.txt" ) ;

    // copy everything from the first non-ws character onwards into a string
    // http://www.cplusplus.com/reference/istream/ws/
    std::istreambuf_iterator<char> first_non_ws( file >> std::ws ), eof ;
    const std::string ltrimmed( first_non_ws, eof ) ;

    std::cout << ltrimmed ;
}