Split strings into fields nondestructively.

* lib/splitstring.c: New file; defines splitstring(), which will
non-destructively locate character-separated fields in a string.
* lib/splitstring.h: New file; declares splitstring.
* lib/test_splitstring.c: New file; unit test for splitstring.c.
* lib/nextelem.c: Delete (obsoleted by splitstring.c).
* lib/nextelem.h: Delete (obsoleted by splitstring.h).
* lib/Makefile.am (libfind_a_SOURCES): Add splitstring.c,
splitstring.c.  Remove nextelem.c, nextelem.h.
(check_PROGRAMS): Add test_splitstring.
(TESTS): Add test_splitstring.
(test_splitstring_SOURCES): Sources for the
test_splitstring unit test.
* locate/locate.c: Include splitstring.h rather than nextelem.h.
(dolocate): Use splitstring rather than next_element.  In places
where we need a nul-terminated string, use strndup() to create it.
Convert some space-tab sequences to regular spacing.
* find/parser.c: Include splitstring.h rather than nextelem.h.
(check_path_safety): Use splitstring rather than next_element.
* import-gnulib.config (modules): Depend on the module strndup.
* cfg.mk: Exempt lib/test_splitstring.c from calling
bindtextdomain or set_program_name.

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/splitstring.h b/lib/splitstring.h
new file mode 100644
index 00000000..c91f7e75
--- /dev/null
+++ b/lib/splitstring.h
@@ -0,0 +1,40 @@
+/* splitstring.h -- split a const string into fields.
+   Copyright (C) 2011 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * Written by James Youngman.
+ */
+
+/* Split a string into fields.   The string is never modified.
+ *
+ * A false return value indicates that there are no more fields.
+ * Otherwise the next field is at the poisition indicated by *POS and
+ * has length *LEN.
+ *
+ * Set FIRST to true only on the first call for any given value of s.
+ * *POS and *LEN do not need to be initialised in this case.
+ * On subsequent calls, these values should be left at the values
+ * set by the last call.
+ *
+ * Any character in SEPARATORS is taken to be a field separator.
+ * Consecutive field separators are taken to indicate the presence of
+ * an empty field.
+ */
+#include <stdbool.h>
+#include <stddef.h>
+
+bool splitstring(const char *s, const char *separators,
+		 bool first, size_t *pos, size_t *len);