#include <stdio.h>
#include <stdlib.h>
int main()
{
	char c;
	char* string;
	int i = 0, j = 0;
	string = (char*)malloc(sizeof(char));
	printf("insert string:\n");
	do
	{
		c = getchar();//get a char
		if(c >= 'a' && c <= 'z') // for instance get only low case letters..
		{
			string = (char*)realloc(string,sizeof(char)*(i+1));
			string[i] = c;
			i++;
		}
	}while(c != '\n');
	printf("Lower case string:\n");
	for(j = 0 ; j < i ; j++)
		printf("%c",string[j]);
	printf("\n");
	free(string);
	return 0;
}
[\code]