[RFC/PATCH v2 3/5] libbb: add ends_with() function

[walter harms]

Am 21.08.2015 16:23, schrieb Bartosz Golaszewski:
> This function checks if given key can be found at the end of the string.
> 
> Signed-off-by: Bartosz Golaszewski <bartekgola at gmail.com>
> ---
>  include/libbb.h              |  1 +
>  libbb/compare_string_array.c | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/include/libbb.h b/include/libbb.h
> index a56b684..7b41c9b 100644
> --- a/include/libbb.h
> +++ b/include/libbb.h
> @@ -422,6 +422,7 @@ const char *bb_basename(const char *name) FAST_FUNC;
>  char *last_char_is(const char *s, int c) FAST_FUNC;
>  const char* endofname(const char *name) FAST_FUNC;
>  char *is_prefixed_with(const char *string, const char *key) FAST_FUNC;
> +int ends_with(const char *str, const char *key) FAST_FUNC;
>  
>  int ndelay_on(int fd) FAST_FUNC;
>  int ndelay_off(int fd) FAST_FUNC;
> diff --git a/libbb/compare_string_array.c b/libbb/compare_string_array.c
> index e24815a..a2d77c7 100644
> --- a/libbb/compare_string_array.c
> +++ b/libbb/compare_string_array.c
> @@ -23,6 +23,19 @@ char* FAST_FUNC is_prefixed_with(const char *string, const char *key)
>  #endif
>  }
>  
> +int FAST_FUNC ends_with(const char *str, const char *key)
> +{
> +	size_t str_len = strlen(str), key_len = strlen(key);
> +
> +	if (str_len >= key_len) {
> +		if (strcmp(str + str_len - key_len, key) == 0) {
> +			return 1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +

maybe its a bit late but ...

the function name is a bit unfortunate whats about has_suffix() ?

you can improve readability by returning strcmp directly and calculating
the len immediately.

int has_suffix(const char *str, const char *key)
{
        size_t len = strlen(str)-strlen(key);

        if (len < 0 )
		return -1;

        return strcmp(str + len, key);
}

re,
 wh


>  /* returns the array index of the string */
>  /* (index of first match is returned, or -1) */
>  int FAST_FUNC index_in_str_array(const char *const string_array[], const char *key)
> @@ -110,3 +123,20 @@ smallint FAST_FUNC yesno(const char *str)
>  	return ret / 3;
>  }
>  #endif
> +
> +#if ENABLE_UNIT_TEST
> +
> +BBUNIT_DEFINE_TEST(ends_with)
> +{
> +	BBUNIT_ASSERT_TRUE(ends_with("foo bar", "bar"));
> +	BBUNIT_ASSERT_TRUE(ends_with("foo", "foo"));
> +	BBUNIT_ASSERT_TRUE(ends_with("foo", ""));
> +	BBUNIT_ASSERT_TRUE(ends_with("", ""));
> +
> +	BBUNIT_ASSERT_FALSE(ends_with("foo", "bar foo"));
> +	BBUNIT_ASSERT_FALSE(ends_with("foo foo", "bar"));
> +
> +	BBUNIT_ENDTEST;
> +}
> +
> +#endif /* ENABLE_UNIT_TEST */