release/src/router/busybox/libbb/compare_string_array.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  */
   5
   6 #include "libbb.h"
   7
   8 /*
   9  * Return NULL if string is not prefixed with key. Return pointer to the
  10  * first character in string after the prefix key. If key is an empty string,
  11  * return pointer to the beginning of string.
  12  */
  13 char* FAST_FUNC is_prefixed_with(const char *string, const char *key)
  14 {
  15 #if 0   /* Two passes over key - probably slower */
  16         int len = strlen(key);
  17         if (strncmp(string, key, len) == 0)
  18                 return string + len;
  19         return NULL;
  20 #else   /* Open-coded */
  21         while (*key != '\0') {
  22                 if (*key != *string)
  23                         return NULL;
  24                 key++;
  25                 string++;
  26         }
  27         return (char*)string;
  28 #endif
  29 }
  30
  31 /*
  32  * Return NULL if string is not suffixed with key. Return pointer to the
  33  * beginning of prefix key in string. If key is an empty string return pointer
  34  * to the end of string.
  35  */
  36 char* FAST_FUNC is_suffixed_with(const char *string, const char *key)
  37 {
  38         size_t key_len = strlen(key);
  39         ssize_t len_diff = strlen(string) - key_len;
  40
  41         if (len_diff >= 0) {
  42                 string += len_diff;
  43                 if (strcmp(string, key) == 0) {
  44                         return (char*)string;
  45                 }
  46         }
  47
  48         return NULL;
  49 }
  50
  51 /* returns the array index of the string */
  52 /* (index of first match is returned, or -1) */
  53 int FAST_FUNC index_in_str_array(const char *const string_array[], const char *key)
  54 {
  55         int i;
  56
  57         for (i = 0; string_array[i] != 0; i++) {
  58                 if (strcmp(string_array[i], key) == 0) {
  59                         return i;
  60                 }
  61         }
  62         return -1;
  63 }
  64
  65 int FAST_FUNC index_in_strings(const char *strings, const char *key)
  66 {
  67         int idx = 0;
  68
  69         while (*strings) {
  70                 if (strcmp(strings, key) == 0) {
  71                         return idx;
  72                 }
  73                 strings += strlen(strings) + 1; /* skip NUL */
  74                 idx++;
  75         }
  76         return -1;
  77 }
  78
  79 /* returns the array index of the string, even if it matches only a beginning */
  80 /* (index of first match is returned, or -1) */
  81 #ifdef UNUSED
  82 int FAST_FUNC index_in_substr_array(const char *const string_array[], const char *key)
  83 {
  84         int i;
  85         if (key[0]) {
  86                 for (i = 0; string_array[i] != 0; i++) {
  87                         if (is_prefixed_with(string_array[i], key)) {
  88                                 return i;
  89                         }
  90                 }
  91         }
  92         return -1;
  93 }
  94 #endif
  95
  96 int FAST_FUNC index_in_substrings(const char *strings, const char *key)
  97 {
  98         int matched_idx = -1;
  99         const int len = strlen(key);
 100
 101         if (len) {
 102                 int idx = 0;
 103                 while (*strings) {
 104                         if (strncmp(strings, key, len) == 0) {
 105                                 if (strings[len] == '\0')
 106                                         return idx; /* exact match */
 107                                 if (matched_idx >= 0)
 108                                         return -1; /* ambiguous match */
 109                                 matched_idx = idx;
 110                         }
 111                         strings += strlen(strings) + 1; /* skip NUL */
 112                         idx++;
 113                 }
 114         }
 115         return matched_idx;
 116 }
 117
 118 const char* FAST_FUNC nth_string(const char *strings, int n)
 119 {
 120         while (n) {
 121                 n--;
 122                 strings += strlen(strings) + 1;
 123         }
 124         return strings;
 125 }
 126
 127 #ifdef UNUSED_SO_FAR /* only brctl.c needs it yet */
 128 /* Returns 0 for no, 1 for yes or a negative value on error.  */
 129 smallint FAST_FUNC yesno(const char *str)
 130 {
 131         static const char no_yes[] ALIGN1 =
 132                 "0\0" "off\0" "no\0"
 133                 "1\0" "on\0" "yes\0";
 134         int ret = index_in_substrings(no_yes, str);
 135         return ret / 3;
 136 }
 137 #endif
 138
 139 #if ENABLE_UNIT_TEST
 140
 141 BBUNIT_DEFINE_TEST(is_prefixed_with)
 142 {
 143         BBUNIT_ASSERT_STREQ(" bar", is_prefixed_with("foo bar", "foo"));
 144         BBUNIT_ASSERT_STREQ("bar", is_prefixed_with("foo bar", "foo "));
 145         BBUNIT_ASSERT_STREQ("", is_prefixed_with("foo", "foo"));
 146         BBUNIT_ASSERT_STREQ("foo", is_prefixed_with("foo", ""));
 147         BBUNIT_ASSERT_STREQ("", is_prefixed_with("", ""));
 148
 149         BBUNIT_ASSERT_NULL(is_prefixed_with("foo", "bar foo"));
 150         BBUNIT_ASSERT_NULL(is_prefixed_with("foo foo", "bar"));
 151         BBUNIT_ASSERT_NULL(is_prefixed_with("", "foo"));
 152
 153         BBUNIT_ENDTEST;
 154 }
 155
 156 BBUNIT_DEFINE_TEST(is_suffixed_with)
 157 {
 158         BBUNIT_ASSERT_STREQ("bar", is_suffixed_with("foo bar", "bar"));
 159         BBUNIT_ASSERT_STREQ("foo", is_suffixed_with("foo", "foo"));
 160         BBUNIT_ASSERT_STREQ("", is_suffixed_with("foo", ""));
 161         BBUNIT_ASSERT_STREQ("", is_suffixed_with("", ""));
 162         BBUNIT_ASSERT_STREQ("foo", is_suffixed_with("barfoofoo", "foo"));
 163
 164         BBUNIT_ASSERT_NULL(is_suffixed_with("foo", "bar foo"));
 165         BBUNIT_ASSERT_NULL(is_suffixed_with("foo foo", "bar"));
 166         BBUNIT_ASSERT_NULL(is_suffixed_with("", "foo"));
 167
 168         BBUNIT_ENDTEST;
 169 }
 170
 171 #endif /* ENABLE_UNIT_TEST */