Implement getdelim(3) and getline(3).

Prompted in a mail to tech@ by Jan Klemkow (j-dot-klemkow-at-wemelug-dot-de)
but this is based on NetBSD's implementation instead with some tweaks by me.
Further improvements would happen in tree.

ok millert@; discussed with many others
ports cleanup by naddy@, sthen@. Antti Harri, Gonzalo L. R. and myself.

1 files changed, 134 insertions, 0 deletions

diff --git a/lib/libc/stdio/getdelim.c b/lib/libc/stdio/getdelim.c
new file mode 100644
index 00000000000..dcde0c34e61
--- /dev/null
+++ b/lib/libc/stdio/getdelim.c
@@ -0,0 +1,134 @@
+/*	$OpenBSD: getdelim.c,v 1.1 2012/03/21 23:44:35 fgsch Exp $	*/
+/* $NetBSD: getdelim.c,v 1.13 2011/07/22 23:12:30 joerg Exp $ */
+
+/*
+ * Copyright (c) 2009 The NetBSD Foundation, Inc.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Roy Marples.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "local.h"
+
+/* Minimum buffer size we create.
+ * This should allow config files to fit into our power of 2 buffer growth
+ * without the need for a realloc. */
+#define MINBUF	128
+
+ssize_t
+getdelim(char **__restrict buf, size_t *__restrict buflen,
+    int sep, FILE *__restrict fp)
+{
+	unsigned char *p;
+	size_t len, newlen, off;
+	char *newb;
+
+	FLOCKFILE(fp);
+
+	if (buf == NULL || buflen == NULL) {
+		errno = EINVAL;
+		goto error;
+	}
+
+	/* If buf is NULL, we have to assume a size of zero */
+	if (*buf == NULL)
+		*buflen = 0;
+
+	_SET_ORIENTATION(fp, -1);
+	off = 0;
+	do {
+		/* If the input buffer is empty, refill it */
+		if (fp->_r <= 0 && __srefill(fp)) {
+			if (__sferror(fp))
+				goto error;
+			/* No error, so EOF. */
+			break;
+		}
+
+		/* Scan through looking for the separator */
+		p = memchr(fp->_p, sep, (size_t)fp->_r);
+		if (p == NULL)
+			len = fp->_r;
+		else
+			len = (p - fp->_p) + 1;
+
+		newlen = off + len;
+		/* Ensure we can handle it */
+		if (newlen < off || newlen > SSIZE_MAX) {
+			errno = EOVERFLOW;
+			goto error;
+		}
+		newlen++; /* reserve space for the NULL terminator */
+		if (newlen > *buflen) {
+			if (newlen < MINBUF)
+				newlen = MINBUF;
+#define powerof2(x) ((((x)-1)&(x))==0)
+			if (!powerof2(newlen)) {
+				/* Grow the buffer to the next power of 2 */
+				newlen--;
+				newlen |= newlen >> 1;
+				newlen |= newlen >> 2;
+				newlen |= newlen >> 4;
+				newlen |= newlen >> 8;
+				newlen |= newlen >> 16;
+#if SIZE_T_MAX > 0xffffffffU
+				newlen |= newlen >> 32;
+#endif
+				newlen++;
+			}
+
+			newb = realloc(*buf, newlen);
+			if (newb == NULL)
+				goto error;
+			*buf = newb;
+			*buflen = newlen;
+		}
+
+		(void)memcpy((*buf + off), fp->_p, len);
+		/* Safe, len is never greater than what fp->_r can fit. */
+		fp->_r -= (int)len;
+		fp->_p += (int)len;
+		off += len;
+	} while (p == NULL);
+
+	FUNLOCKFILE(fp);
+
+	/* POSIX demands we return -1 on EOF. */
+	if (off == 0)
+		return -1;
+
+	if (*buf != NULL)
+		*(*buf + off) = '\0';
+	return off;
+
+error:
+	fp->_flags |= __SERR;
+	FUNLOCKFILE(fp);
+	return -1;
+}