1 files changed, 73 insertions, 0 deletions
diff --git a/src/c-ares/ares__read_line.c b/src/c-ares/ares__read_line.c
new file mode 100644
index 000000000..c62ad2a2b
--- /dev/null
+++ b/src/c-ares/ares__read_line.c
@@ -0,0 +1,73 @@
+
+/* Copyright 1998 by the Massachusetts Institute of Technology.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ */
+
+#include "ares_setup.h"
+
+#include "ares.h"
+#include "ares_nowarn.h"
+#include "ares_private.h"
+
+/* This is an internal function.  Its contract is to read a line from
+ * a file into a dynamically allocated buffer, zeroing the trailing
+ * newline if there is one.  The calling routine may call
+ * ares__read_line multiple times with the same buf and bufsize
+ * pointers; *buf will be reallocated and *bufsize adjusted as
+ * appropriate.  The initial value of *buf should be NULL.  After the
+ * calling routine is done reading lines, it should free *buf.
+ */
+int ares__read_line(FILE *fp, char **buf, size_t *bufsize)
+{
+  char *newbuf;
+  size_t offset = 0;
+  size_t len;
+
+  if (*buf == NULL)
+    {
+      *buf = ares_malloc(128);
+      if (!*buf)
+        return ARES_ENOMEM;
+      *bufsize = 128;
+    }
+
+  for (;;)
+    {
+      int bytestoread = aresx_uztosi(*bufsize - offset);
+
+      if (!fgets(*buf + offset, bytestoread, fp))
+        return (offset != 0) ? 0 : (ferror(fp)) ? ARES_EFILE : ARES_EOF;
+      len = offset + strlen(*buf + offset);
+      if ((*buf)[len - 1] == '\n')
+        {
+          (*buf)[len - 1] = 0;
+          break;
+        }
+      offset = len;
+      if(len < *bufsize - 1)
+        continue;
+
+      /* Allocate more space. */
+      newbuf = ares_realloc(*buf, *bufsize * 2);
+      if (!newbuf)
+        {
+          ares_free(*buf);
+          *buf = NULL;
+          return ARES_ENOMEM;
+        }
+      *buf = newbuf;
+      *bufsize *= 2;
+    }
+  return ARES_SUCCESS;
+}