la_getline.c

/*	$NetBSD: getline.c,v 1.2 2014/09/16 17:23:50 christos Exp $	*/

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 */

#include "bsdunzip_platform.h"
#ifndef HAVE_GETLINE

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif

static ssize_t
la_getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
{
	char *ptr, *eptr;


	if (*buf == NULL || *bufsiz == 0) {
		*bufsiz = BUFSIZ;
		if ((*buf = malloc(*bufsiz)) == NULL)
			return -1;
	}

	for (ptr = *buf, eptr = *buf + *bufsiz;;) {
		int c = fgetc(fp);
		if (c == -1) {
			if (feof(fp)) {
				ssize_t diff = (ssize_t)(ptr - *buf);
				if (diff != 0) {
					*ptr = '\0';
					return diff;
				}
			}
			return -1;
		}
		*ptr++ = c;
		if (c == delimiter) {
			*ptr = '\0';
			return ptr - *buf;
		}
		if (ptr + 2 >= eptr) {
			char *nbuf;
			size_t nbufsiz = *bufsiz * 2;
			ssize_t d = ptr - *buf;
			if ((nbuf = realloc(*buf, nbufsiz)) == NULL)
				return -1;
			*buf = nbuf;
			*bufsiz = nbufsiz;
			eptr = nbuf + nbufsiz;
			ptr = nbuf + d;
		}
	}
}

ssize_t
getline(char **buf, size_t *bufsiz, FILE *fp)
{
	return la_getdelim(buf, bufsiz, '\n', fp);
}
#endif