#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>

char *
fgetln(stream, len)
    FILE *stream;
    size_t *len;
{
    static char *buffer = NULL;
    static size_t buflen = 0;

    if (buflen == 0) {
	buflen = 512;
	if ((buffer = malloc(buflen+1)) == NULL) {
		fprintf(stderr, "malloc: %s (%zu)\n", strerror(errno),
			buflen+1);
		exit(2);
	}
    }
    if (fgets(buffer, buflen+1, stream) == NULL)
	return NULL;
    *len = strlen(buffer);
    while (*len == buflen && buffer[*len-1] != '\n') {
	if ((buffer = realloc(buffer, 2*buflen+1)) == NULL) {
		fprintf(stderr, "realloc: %s (%zu)\n", strerror(errno),
			2*buflen+1);
		exit(2);
	}
	if (fgets(buffer + buflen, buflen + 1, stream) == NULL)
	    return NULL;
	*len += strlen(buffer + buflen);
	buflen *= 2;
    }
    return buffer;
}