util.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#define MAX_BUFLEN	1024
char *
read_line(int fd)
{
	static char *buf;
	int buflen = 64;
	int i = 0;
	int r;
	int searching = 1;

	while (searching) {
		buf = realloc(buf, buflen);
		if (!buf) {
			fprintf(stderr, "ERR: realloc(%d): %s\n",
				buflen, strerror(errno));
			return NULL;
		}
		memset(buf+i, 0, buflen-i);

		while (i < buflen) {
			r = read(fd, buf+i, 1);
			if (r < 0 && errno != EINTR) {
				/* we should do something with the data */
				fprintf(stderr, "ERR: read(): %s\n",
					strerror(errno));
				return NULL;
			} else if (r == 0) {
				/* signal this in an almost standard way */
				errno = EPIPE;
				return NULL;
			} else if (r == 1) {
				/* scan for a newline */
				if (buf[i] == '\n') {
					searching = 0;
					buf[i] = '\0';
					break;
				}
				i++;
			}
		}
		if (buflen >= MAX_BUFLEN) {
			break;
		}
		buflen *= 2;
	}

	return buf;
}