utils: Add strreplace function

src/libstrongswan/tests/suites/test_utils.c

@@ -384,6 +384,89 @@ START_TEST(test_translate)
 }
 END_TEST
 
+/*******************************************************************************
+ * strreplace
+ */
+
+static struct {
+	char *in;
+	char *out;
+	char *search;
+	char *replace;
+	bool allocated;
+} strreplace_data[] = {
+	/* invalid arguments */
+	{NULL, NULL, NULL, NULL, FALSE},
+	{"", "", NULL, NULL, FALSE},
+	{"", "", "", NULL, FALSE},
+	{"", "", NULL, "", FALSE},
+	{"", "", "", "", FALSE},
+	{"", "", "", "asdf", FALSE},
+	{"", "", "asdf", "", FALSE},
+	{"asdf", "asdf", NULL, NULL, FALSE},
+	{"asdf", "asdf", "", NULL, FALSE},
+	{"asdf", "asdf", NULL, "", FALSE},
+	{"asdf", "asdf", "", "", FALSE},
+	{"asdf", "asdf", "", "asdf", FALSE},
+	{"asdf", "asdf", "asdf", NULL, FALSE},
+	{"qwer", "qwer", "", "asdf", FALSE},
+	/* replacement shorter */
+	{"asdf", "", "asdf", "", TRUE},
+	{"asdfasdf", "", "asdf", "", TRUE},
+	{"asasdfdf", "asdf", "asdf", "", TRUE},
+	{"asdf", "df", "as", "", TRUE},
+	{"asdf", "as", "df", "", TRUE},
+	{"qwer", "qwer", "asdf", "", FALSE},
+	/* replacement same length */
+	{"a", "b", "a", "b", TRUE},
+	{"aaa", "bbb", "a", "b", TRUE},
+	{"aaa", "bbb", "aaa", "bbb", TRUE},
+	{"asdf", "asdf", "asdf", "asdf", TRUE},
+	{"qwer", "qwer", "asdf", "asdf", FALSE},
+	/* replacement longer */
+	{"asdf", "asdf", "", "asdf", FALSE},
+	{"asdf", "asdfasdf", "asdf", "asdfasdf", TRUE},
+	{"asdf", "asdfsdf", "a", "asdf", TRUE},
+	{"asdf", "asdasdf", "f", "asdf", TRUE},
+	{"aaa", "asdfasdfasdf", "a", "asdf", TRUE},
+	{"qwer", "qwer", "asdf", "asdfasdf", FALSE},
+	/* real examples */
+	{"http://x.org/no/spaces", "http://x.org/no/spaces", " ", "%20", FALSE},
+	{"http://x.org/end ", "http://x.org/end%20", " ", "%20", TRUE},
+	{" http://x.org/start", "%20http://x.org/start", " ", "%20", TRUE},
+	{" http://x.org/both ", "%20http://x.org/both%20", " ", "%20", TRUE},
+	{"http://x.org/ /slash", "http://x.org/%20/slash", " ", "%20", TRUE},
+	{"http://x.org/   /three", "http://x.org/%20%20%20/three", " ", "%20", TRUE},
+	{"http://x.org/      ", "http://x.org/%20%20%20%20%20%20", " ", "%20", TRUE},
+	{"http://x.org/%20/encoded", "http://x.org/%20/encoded", " ", "%20", FALSE},
+};
+
+START_TEST(test_strreplace)
+{
+	char *ret;
+
+	ret = strreplace(strreplace_data[_i].in, strreplace_data[_i].search,
+					 strreplace_data[_i].replace);
+	if (ret && strreplace_data[_i].out)
+	{
+		ck_assert_str_eq(ret, strreplace_data[_i].out);
+	}
+	else
+	{
+		ck_assert(ret == strreplace_data[_i].out);
+	}
+	if (strreplace_data[_i].allocated)
+	{
+		ck_assert(ret != strreplace_data[_i].in);
+		free(ret);
+	}
+	else
+	{
+		ck_assert(ret == strreplace_data[_i].in);
+	}
+}
+END_TEST
+
 /*******************************************************************************
  * time_printf_hook
  */
@@ -543,6 +626,10 @@ Suite *utils_suite_create()
 	tcase_add_loop_test(tc, test_translate, 0, countof(translate_data));
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("strreplace");
+	tcase_add_loop_test(tc, test_strreplace, 0, countof(strreplace_data));
+	suite_add_tcase(s, tc);
+
 	tc = tcase_create("printf_hooks");
 	tcase_add_loop_test(tc, test_time_printf_hook, 0, countof(time_data));
 	tcase_add_loop_test(tc, test_time_delta_printf_hook, 0, countof(time_delta_data));

src/libstrongswan/utils/utils.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2012 Tobias Brunner
+ * Copyright (C) 2008-2013 Tobias Brunner
  * Copyright (C) 2005-2008 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -141,6 +141,58 @@ char* translate(char *str, const char *from, const char *to)
 	return str;
 }
 
+/**
+ * Described in header.
+ */
+char* strreplace(const char *str, const char *search, const char *replace)
+{
+	size_t len, slen, rlen, count = 0;
+	char *res, *pos, *found, *dst;
+
+	if (!str || !*str || !search || !*search || !replace)
+	{
+		return (char*)str;
+	}
+	slen = strlen(search);
+	rlen = strlen(replace);
+	if (slen != rlen)
+	{
+		for (pos = (char*)str; (pos = strstr(pos, search)); pos += slen)
+		{
+			found = pos;
+			count++;
+		}
+		if (!count)
+		{
+			return (char*)str;
+		}
+		len = (found - str) + strlen(found) + count * (rlen - slen);
+	}
+	else
+	{
+		len = strlen(str);
+	}
+	found = strstr(str, search);
+	if (!found)
+	{
+		return (char*)str;
+	}
+	dst = res = malloc(len + 1);
+	pos = (char*)str;
+	do
+	{
+		len = found - pos;
+		memcpy(dst, pos, len);
+		dst += len;
+		memcpy(dst, replace, rlen);
+		dst += rlen;
+		pos = found + slen;
+	}
+	while ((found = strstr(pos, search)));
+	strcpy(dst, pos);
+	return res;
+}
+
 /**
  * Described in header.
  */

src/libstrongswan/utils/utils.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2012 Tobias Brunner
+ * Copyright (C) 2008-2013 Tobias Brunner
  * Copyright (C) 2008 Martin Willi
  * Hochschule fuer Technik Rapperswil
  *
@@ -471,6 +471,20 @@ void *memstr(const void *haystack, const char *needle, size_t n);
  */
 char *translate(char *str, const char *from, const char *to);
 
+/**
+ * Replaces all occurences of search in the given string with replace.
+ *
+ * Allocates memory only if anything is replaced in the string.  The original
+ * string is also returned if any of the arguments are invalid (e.g. if search
+ * is empty or any of them are NULL).
+ *
+ * @param str		original string
+ * @param search	string to search for and replace
+ * @param replace	string to replace found occurences with
+ * @return			allocated string, if anything got replaced, str otherwise
+ */
+char *strreplace(const char *str, const char *search, const char *replace);
+
 /**
  * Creates a directory and all required parent directories.
  *