shell: split read builtin from ash

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/shell_common.h

@@ -0,0 +1,35 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Adapted from ash applet code
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Copyright (c) 1989, 1991, 1993, 1994
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
+ * was re-ported from NetBSD and debianized.
+ *
+ * Copyright (c) 2010 Denys Vlasenko
+ * Split from ash.c
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+#ifndef SHELL_COMMON_H
+#define SHELL_COMMON_H 1
+
+PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
+
+#define IFS_BROKEN 1
+
+#if IFS_BROKEN
+extern const char defifsvar[]; /* "IFS= \t\n" */
+#define defifs (defifsvar + 4)
+#else
+extern const char defifs[]; /* " \t\n" */
+#endif
+
+POP_SAVED_FUNCTION_VISIBILITY
+
+#endif