[PATCH 1/2] util: Add suffix check for a string

[PATCH 1/2] util: Add suffix check for a string

[Tim Kourt]

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---
 ell/util.c | 27 +++++++++++++++++++++++++++
 ell/util.h |  1 +
 2 files changed, 28 insertions(+)

diff --git a/ell/util.c b/ell/util.c
index f920895..895f95f 100644
--- a/ell/util.c
+++ b/ell/util.c
@@ -444,6 +444,33 @@ LIB_EXPORT bool l_str_has_prefix(const char *str, const char *prefix)
 }
 
 /**
+ * l_str_has_suffix:
+ * @str: A string to be examined
+ * @suffix: Suffix string
+ *
+ * Determines if the string given by @str ends with the specified @suffix.
+ *
+ * Returns: True if @str ends with the specified @suffix.  False otherwise.
+ */
+LIB_EXPORT bool l_str_has_suffix(const char *str, const char *suffix)
+{
+	int str_len_diff;
+
+	if (unlikely(!str))
+		return false;
+
+	if (unlikely(!suffix))
+		return false;
+
+	str_len_diff = strlen(str) - strlen(suffix);
+
+	if (str_len_diff < 0)
+		return false;
+
+	return !strcmp(&str[str_len_diff], suffix);
+}
+
+/**
  * l_util_hexstring:
  * @buf: buffer pointer
  * @len: length of buffer
diff --git a/ell/util.h b/ell/util.h
index f6a88a0..92e7c8a 100644
--- a/ell/util.h
+++ b/ell/util.h
@@ -208,6 +208,7 @@ char **l_strsplit_set(const char *str, const char *separators);
 char *l_strjoinv(char **str_array, const char delim);
 
 bool l_str_has_prefix(const char *str, const char *prefix);
+bool l_str_has_suffix(const char *str, const char *suffix);
 
 char *l_util_hexstring(const unsigned char *buf, size_t len);
 unsigned char *l_util_from_hexstring(const char *str, size_t *out_len);
-- 
2.5.0

[PATCH 2/2] unit: Add tests for the suffix check for a string

[Tim Kourt]

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---
 unit/test-util.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/unit/test-util.c b/unit/test-util.c
index d72646f..427c74a 100644
--- a/unit/test-util.c
+++ b/unit/test-util.c
@@ -62,6 +62,18 @@ static void test_from_hexstring(const void *test_data)
 	assert(!bytes);
 }
 
+static void test_has_suffix(const void *test_data)
+{
+	const char *str = "string";
+	const char *suffix = "ing";
+
+	assert(l_str_has_suffix(str, suffix));
+	assert(l_str_has_suffix(str, str));
+	assert(!l_str_has_suffix(NULL, suffix));
+	assert(!l_str_has_suffix(str, NULL));
+	assert(!l_str_has_suffix(suffix, str));
+}
+
 int main(int argc, char *argv[])
 {
 	l_test_init(&argc, &argv);
@@ -69,5 +81,7 @@ int main(int argc, char *argv[])
 	l_test_add("l_util_hexstring", test_hexstring, NULL);
 	l_test_add("l_util_from_hexstring", test_from_hexstring, NULL);
 
+	l_test_add("l_util_has_suffix", test_has_suffix, NULL);
+
 	return l_test_run();
 }
-- 
2.5.0

Re: [PATCH 1/2] util: Add suffix check for a string

[Mat Martineau]

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Tim,

On Fri, 22 Apr 2016, Tim Kourt wrote:

> ---
> ell/util.c | 27 +++++++++++++++++++++++++++
> ell/util.h |  1 +
> 2 files changed, 28 insertions(+)
>
> diff --git a/ell/util.c b/ell/util.c
> index f920895..895f95f 100644
> --- a/ell/util.c
> +++ b/ell/util.c
> @@ -444,6 +444,33 @@ LIB_EXPORT bool l_str_has_prefix(const char *str, const char *prefix)
> }
>
> /**
> + * l_str_has_suffix:
> + * @str: A string to be examined
> + * @suffix: Suffix string
> + *
> + * Determines if the string given by @str ends with the specified @suffix.
> + *
> + * Returns: True if @str ends with the specified @suffix.  False otherwise.
> + */
> +LIB_EXPORT bool l_str_has_suffix(const char *str, const char *suffix)
> +{
> +	int str_len_diff;
> +
> +	if (unlikely(!str))
> +		return false;
> +
> +	if (unlikely(!suffix))
> +		return false;
> +
> +	str_len_diff = strlen(str) - strlen(suffix);

strlen returns size_t (unsigned), which is a 64-bit type on 64-bit 
platforms. Hopefully no one is throwing around 4+GB null-terminated 
strings, but you never know. You can make sure the suffix is shorter 
before calculating the difference, avoiding signed integers altogether.

> +
> +	if (str_len_diff < 0)
> +		return false;
> +
> +	return !strcmp(&str[str_len_diff], suffix);
> +}


Regards,

Mat

Re: [PATCH 1/2] util: Add suffix check for a string

[Denis Kenzior]

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Hi Tim,

 >> +
>> +    str_len_diff = strlen(str) - strlen(suffix);
>
> strlen returns size_t (unsigned), which is a 64-bit type on 64-bit
> platforms. Hopefully no one is throwing around 4+GB null-terminated
> strings, but you never know. You can make sure the suffix is shorter
> before calculating the difference, avoiding signed integers altogether.

+1.  Please fix/resubmit this one.

Regards,
-Denis