libknot internal: implement strstrip()

src/libknot/internal/mem.c

@@ -14,6 +14,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <ctype.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -131,6 +132,31 @@ char *strcdup(const char *s1, const char *s2)
 	return dst;
 }
 
+char *strstrip(const char *str)
+{
+	// leading white-spaces
+	const char *scan = str;
+	while (isspace((int)scan[0])) {
+		scan += 1;
+	}
+
+	// trailing white-spaces
+	size_t len = strlen(scan);
+	while (len > 1 && isspace((int)scan[len - 1])) {
+		len -= 1;
+	}
+
+	char *trimmed = malloc(len);
+	if (!trimmed) {
+		return NULL;
+	}
+
+	memcpy(trimmed, scan, len + 1);
+	trimmed[len] = '\0';
+
+	return trimmed;
+}
+
 #ifdef MEM_DEBUG
 /*
  * ((destructor)) attribute executes this function after main().

src/libknot/internal/mem.h

@@ -80,3 +80,10 @@ char *sprintf_alloc(const char *fmt, ...);
  * \retval NULL on error.
  */
 char *strcdup(const char *s1, const char *s2);
+
+/*!
+ * \brief Create a copy of a string skipping leading and trailing white spaces.
+ *
+ * \return Newly allocated string, NULL in case of error.
+ */
+char *strstrip(const char *str);

tests/.gitignore

@@ -19,6 +19,7 @@ endian
 fdset
 hattrie
 hhash
+internal_mem
 journal
 namedb
 net_shortwrite

tests/Makefile.am

@@ -23,6 +23,7 @@ check_PROGRAMS = \
 	fdset				\
 	hattrie				\
 	hhash				\
+	internal_mem			\
 	journal				\
 	namedb				\
 	net_shortwrite			\

tests/internal_mem.c

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    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/>.
+*/
+
+#include <tap/basic.h>
+
+#include "libknot/internal/mem.h"
+
+static void test_strstrip(void)
+{
+	char *c = NULL;
+
+	c = strstrip("hello");
+	is_string("hello", c, "strstrip: no whitespace");
+	free(c);
+
+	c = strstrip("world \n");
+	is_string("world", c, "strstrip: trailing whitespace");
+	free(c);
+
+	c = strstrip(" \n banana");
+	is_string("banana", c, "strstrip: leading whitespace");
+	free(c);
+
+	c = strstrip(" \t hello  world   \n");
+	is_string("hello  world", c, "strstrip: leading and trailing");
+	free(c);
+
+	c = strstrip("");
+	is_string("", c, "strstrip: empty string");
+	free(c);
+}
+
+int main(int argc, char *argv[])
+{
+	plan_lazy();
+
+	test_strstrip();
+
+	return 0;
+}