#include <stdio.h>
#include <stdlib.h>

char *mygetline(void);

int main()
{
	char *p;

	printf("Please type one line and press RETURN.\n");
	p = mygetline();

	printf("%s\n", p);
	free(p);
	return EXIT_SUCCESS;
}

/* Let the user input a line of any length.  Allocate a block of memory for the
line, excluding the RETURN that the user typed to terminate it.  Store the line
in the block, including a terminating '\0', and return the address of the first
char of the block. */

char *mygetline(void)
{
	size_t i = 0;
	char *p;
	char *q;
	int c;

	p = malloc(++i);
	if (p == NULL) {
		printf("Can't allocate %u bytes.\n", i);
		exit(EXIT_FAILURE);
	}

	while ((c = getchar()) != EOF && c != '\n') {
		p[i-1] = c;
		q = realloc(p, ++i);
		if (q == NULL) {
			printf("Can't allocate %u bytes.\n", i);
			exit(EXIT_FAILURE);
		}
		p = q;
	}

	p[i-1] = '\0';
	return p;
}