busybox/libbb/compare_string_array.c
Denys Vlasenko 68acc0f835 libbb: make is_suffixed_with() return pointer inside string, not key.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-08-25 21:47:33 +02:00

171 lines
4.0 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
/*
* Return NULL if string is not prefixed with key. Return pointer to the
* first character in string after the prefix key. If key is an empty string,
* return pointer to the beginning of string.
*/
char* FAST_FUNC is_prefixed_with(const char *string, const char *key)
{
#if 0 /* Two passes over key - probably slower */
int len = strlen(key);
if (strncmp(string, key, len) == 0)
return string + len;
return NULL;
#else /* Open-coded */
while (*key != '\0') {
if (*key != *string)
return NULL;
key++;
string++;
}
return (char*)string;
#endif
}
/*
* Return NULL if string is not suffixed with key. Return pointer to the
* beginning of prefix key in string. If key is an empty string return pointer
* to the end of string.
*/
char* FAST_FUNC is_suffixed_with(const char *string, const char *key)
{
size_t key_len = strlen(key);
ssize_t len_diff = strlen(string) - key_len;
if (len_diff >= 0) {
string += len_diff;
if (strcmp(string, key) == 0) {
return (char*)string;
}
}
return NULL;
}
/* 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)
{
int i;
for (i = 0; string_array[i] != 0; i++) {
if (strcmp(string_array[i], key) == 0) {
return i;
}
}
return -1;
}
int FAST_FUNC index_in_strings(const char *strings, const char *key)
{
int idx = 0;
while (*strings) {
if (strcmp(strings, key) == 0) {
return idx;
}
strings += strlen(strings) + 1; /* skip NUL */
idx++;
}
return -1;
}
/* returns the array index of the string, even if it matches only a beginning */
/* (index of first match is returned, or -1) */
#ifdef UNUSED
int FAST_FUNC index_in_substr_array(const char *const string_array[], const char *key)
{
int i;
if (key[0]) {
for (i = 0; string_array[i] != 0; i++) {
if (is_prefixed_with(string_array[i], key)) {
return i;
}
}
}
return -1;
}
#endif
int FAST_FUNC index_in_substrings(const char *strings, const char *key)
{
int matched_idx = -1;
const int len = strlen(key);
if (len) {
int idx = 0;
while (*strings) {
if (strncmp(strings, key, len) == 0) {
if (strings[len] == '\0')
return idx; /* exact match */
if (matched_idx >= 0)
return -1; /* ambiguous match */
matched_idx = idx;
}
strings += strlen(strings) + 1; /* skip NUL */
idx++;
}
}
return matched_idx;
}
const char* FAST_FUNC nth_string(const char *strings, int n)
{
while (n) {
n--;
strings += strlen(strings) + 1;
}
return strings;
}
#ifdef UNUSED_SO_FAR /* only brctl.c needs it yet */
/* Returns 0 for no, 1 for yes or a negative value on error. */
smallint FAST_FUNC yesno(const char *str)
{
static const char no_yes[] ALIGN1 =
"0\0" "off\0" "no\0"
"1\0" "on\0" "yes\0";
int ret = index_in_substrings(no_yes, str);
return ret / 3;
}
#endif
#if ENABLE_UNIT_TEST
BBUNIT_DEFINE_TEST(is_prefixed_with)
{
BBUNIT_ASSERT_STREQ(" bar", is_prefixed_with("foo bar", "foo"));
BBUNIT_ASSERT_STREQ("bar", is_prefixed_with("foo bar", "foo "));
BBUNIT_ASSERT_STREQ("", is_prefixed_with("foo", "foo"));
BBUNIT_ASSERT_STREQ("foo", is_prefixed_with("foo", ""));
BBUNIT_ASSERT_STREQ("", is_prefixed_with("", ""));
BBUNIT_ASSERT_NULL(is_prefixed_with("foo", "bar foo"));
BBUNIT_ASSERT_NULL(is_prefixed_with("foo foo", "bar"));
BBUNIT_ASSERT_NULL(is_prefixed_with("", "foo"));
BBUNIT_ENDTEST;
}
BBUNIT_DEFINE_TEST(is_suffixed_with)
{
BBUNIT_ASSERT_STREQ("bar", is_suffixed_with("foo bar", "bar"));
BBUNIT_ASSERT_STREQ("foo", is_suffixed_with("foo", "foo"));
BBUNIT_ASSERT_STREQ("", is_suffixed_with("foo", ""));
BBUNIT_ASSERT_STREQ("", is_suffixed_with("", ""));
BBUNIT_ASSERT_NULL(is_suffixed_with("foo", "bar foo"));
BBUNIT_ASSERT_NULL(is_suffixed_with("foo foo", "bar"));
BBUNIT_ASSERT_NULL(is_suffixed_with("", "foo"));
BBUNIT_ENDTEST;
}
#endif /* ENABLE_UNIT_TEST */