getline: split out for darwin systems

At least on OS X 10.5 and older, getline does not exist.  So split out the
function from the mingw code so that we can pull it in for Darwin systems.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/tools/getline.c b/tools/getline.c
new file mode 100644
index 0000000..3ba52a3
--- /dev/null
+++ b/tools/getline.c
@@ -0,0 +1,101 @@
+/* getline.c -- Replacement for GNU C library function getline
+
+Copyright (C) 1993, 1996, 2001, 2002 Free Software Foundation, Inc.
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/* Written by Jan Brittenson, bson@gnu.ai.mit.edu.  */
+
+#include <assert.h>
+#include <stdio.h>
+
+/* Always add at least this many bytes when extending the buffer.  */
+#define MIN_CHUNK 64
+
+/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
+   + OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
+   malloc (or NULL), pointing to *N characters of space.  It is realloc'd
+   as necessary.  Return the number of characters read (not including the
+   null terminator), or -1 on error or EOF.
+   NOTE: There is another getstr() function declared in <curses.h>.  */
+static int getstr(char **lineptr, size_t *n, FILE *stream,
+		  char terminator, size_t offset)
+{
+	int nchars_avail;	/* Allocated but unused chars in *LINEPTR.  */
+	char *read_pos;		/* Where we're reading into *LINEPTR. */
+	int ret;
+
+	if (!lineptr || !n || !stream)
+		return -1;
+
+	if (!*lineptr) {
+		*n = MIN_CHUNK;
+		*lineptr = malloc(*n);
+		if (!*lineptr)
+			return -1;
+	}
+
+	nchars_avail = *n - offset;
+	read_pos = *lineptr + offset;
+
+	for (;;) {
+		register int c = getc(stream);
+
+		/* We always want at least one char left in the buffer, since we
+		   always (unless we get an error while reading the first char)
+		   NUL-terminate the line buffer.  */
+
+		assert(*n - nchars_avail == read_pos - *lineptr);
+		if (nchars_avail < 2) {
+			if (*n > MIN_CHUNK)
+				*n *= 2;
+			else
+				*n += MIN_CHUNK;
+
+			nchars_avail = *n + *lineptr - read_pos;
+			*lineptr = realloc(*lineptr, *n);
+			if (!*lineptr)
+				return -1;
+			read_pos = *n - nchars_avail + *lineptr;
+			assert(*n - nchars_avail == read_pos - *lineptr);
+		}
+
+		if (c == EOF || ferror (stream)) {
+			/* Return partial line, if any.  */
+			if (read_pos == *lineptr)
+				return -1;
+			else
+				break;
+		}
+
+		*read_pos++ = c;
+		nchars_avail--;
+
+		if (c == terminator)
+			/* Return the line.  */
+			break;
+	}
+
+	/* Done - NUL terminate and return the number of chars read.  */
+	*read_pos = '\0';
+
+	ret = read_pos - (*lineptr + offset);
+	return ret;
+}
+
+int getline (char **lineptr, size_t *n, FILE *stream)
+{
+	return getstr(lineptr, n, stream, '\n', 0);
+}