#include <stdio.h>

/*
 * To read strings you have essentially 2 templates:
 *
 * - %s: the string is considered to be over whenever
 *       a whitespace is encountered.
 *
 * - %[...] you can specify what characters make up your string.
 *
 *   In the specification, '-' stands for a range of characters, 
 *   unless it is the first or the last character, in which case 
 *   it stands for itself.
 *
 *       E.g. %[0-9a-zA-Z] matches a string made of digits,
 *                         lower case and upper case letters.
 *            %[a-z-]      matches a string made of lower case letters
 *                         and hyphens (-).
 *            %[-0-9_ a-z] matches a string made of digits, hyphens,
 *                         spaces and lower case letters.
 *
 *       (see the libc manual for a full explaination, the %[ template
 *       is very flexible and handy).
 */


/*
 * Whenever you read a string you have to _preallocate_ a buffer of the
 * proper size. That is, if you want to read a string that is long AT
 * MOST 100 characters, you have to initialize a buffer of size 101 and
 * pass it as the argument of the %s or %[ template.
 *
 * E.g:
 *
 *   char string[101];
 *   ...
 *   scanf("%[ a-b0-9]", string);
 */
 
/*
 * PROBLEM: the string that you read might be larger than the buffer,
 * causing various problems (buffer overflows, segmentation faults...).
 *
 * SOLUTION: you can tell your templates that your string has a maximum
 * length. Actually, you ****** M U S T ****** do it. (if you didn't
 * notice, it is important).
 *
 * You can do it by putting the maximum length to match between the '%'
 * and the 's' or '[' in the template definition.
 *
 * E.g.:
 *
 *   char buffer[55];
 *   ....
 *   scanf("%54s", buffer);
 *   ...
 *   scanf("%54[a-z0-9_]", buffer);
 *
 * SPECIFING THE MAXIMUM DIMENSION OF THE ACCEPTING BUFFER IS THE PROPER
 * AND SAFE WAY TO READ STRINGS IN C.
 */

/*
 * If the string is longer, then the remaining characters are left to
 * be consumed by the next call to scanf.
 */


int main(void)
{

	char longbuffer[21];

	// A proper way to handle input strings
	printf("Inserisci una stringa (cifre, lettere non accentate e spazi).\n");
	scanf("%20[a-zA-Z0-9 ]", longbuffer);
	printf(" ==> Ho letto: %s\n", longbuffer);

	return(0);
}