1 /* vi: set sw=4 ts=4: */
2 /*
3 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
4 */
5 #include "libbb.h"
6
7 /*
8 * Return NULL if string is not prefixed with key. Return pointer to the
9 * first character in string after the prefix key. If key is an empty string,
10 * return pointer to the beginning of string.
11 */
is_prefixed_with(const char * string,const char * key)12 char* FAST_FUNC is_prefixed_with(const char *string, const char *key)
13 {
14 #if 0 /* Two passes over key - probably slower */
15 int len = strlen(key);
16 if (strncmp(string, key, len) == 0)
17 return string + len;
18 return NULL;
19 #else /* Open-coded */
20 while (*key != '\0') {
21 if (*key != *string)
22 return NULL;
23 key++;
24 string++;
25 }
26 return (char*)string;
27 #endif
28 }
29
30 /*
31 * Return NULL if string is not suffixed with key. Return pointer to the
32 * beginning of prefix key in string. If key is an empty string return pointer
33 * to the end of string.
34 */
is_suffixed_with(const char * string,const char * key)35 char* FAST_FUNC is_suffixed_with(const char *string, const char *key)
36 {
37 size_t key_len = strlen(key);
38 ssize_t len_diff = strlen(string) - key_len;
39
40 if (len_diff >= 0) {
41 string += len_diff;
42 if (strcmp(string, key) == 0) {
43 return (char*)string;
44 }
45 }
46
47 return NULL;
48 }
49
50 /* returns the array index of the string */
51 /* (index of first match is returned, or -1) */
index_in_str_array(const char * const string_array[],const char * key)52 int FAST_FUNC index_in_str_array(const char *const string_array[], const char *key)
53 {
54 int i;
55
56 for (i = 0; string_array[i] != 0; i++) {
57 if (strcmp(string_array[i], key) == 0) {
58 return i;
59 }
60 }
61 return -1;
62 }
63
index_in_strings(const char * strings,const char * key)64 int FAST_FUNC index_in_strings(const char *strings, const char *key)
65 {
66 int j, idx = 0;
67
68 while (*strings) {
69 /* Do we see "key\0" at current position in strings? */
70 for (j = 0; *strings == key[j]; ++j) {
71 if (*strings++ == '\0') {
72 //bb_error_msg("found:'%s' i:%u", key, idx);
73 return idx; /* yes */
74 }
75 }
76 /* No. Move to the start of the next string. */
77 while (*strings++ != '\0')
78 continue;
79 idx++;
80 }
81 return -1;
82 }
83
84 /* returns the array index of the string, even if it matches only a beginning */
85 /* (index of first match is returned, or -1) */
86 #ifdef UNUSED
index_in_substr_array(const char * const string_array[],const char * key)87 int FAST_FUNC index_in_substr_array(const char *const string_array[], const char *key)
88 {
89 int i;
90 if (key[0]) {
91 for (i = 0; string_array[i] != 0; i++) {
92 if (is_prefixed_with(string_array[i], key)) {
93 return i;
94 }
95 }
96 }
97 return -1;
98 }
99 #endif
100
index_in_substrings(const char * strings,const char * key)101 int FAST_FUNC index_in_substrings(const char *strings, const char *key)
102 {
103 int matched_idx = -1;
104 const int len = strlen(key);
105
106 if (len) {
107 int idx = 0;
108 while (*strings) {
109 if (strncmp(strings, key, len) == 0) {
110 if (strings[len] == '\0')
111 return idx; /* exact match */
112 if (matched_idx >= 0)
113 return -1; /* ambiguous match */
114 matched_idx = idx;
115 }
116 strings += strlen(strings) + 1; /* skip NUL */
117 idx++;
118 }
119 }
120 return matched_idx;
121 }
122
nth_string(const char * strings,int n)123 const char* FAST_FUNC nth_string(const char *strings, int n)
124 {
125 while (n) {
126 if (*strings++ == '\0') {
127 if (*strings == '\0') /* reached end of strings */
128 break;
129 n--;
130 }
131 }
132 return strings;
133 }
134
135 #ifdef UNUSED_SO_FAR /* only brctl.c needs it yet */
136 /* Returns 0 for no, 1 for yes or a negative value on error. */
yesno(const char * str)137 smallint FAST_FUNC yesno(const char *str)
138 {
139 static const char no_yes[] ALIGN1 =
140 "0\0" "off\0" "no\0"
141 "1\0" "on\0" "yes\0";
142 int ret = index_in_substrings(no_yes, str);
143 return ret / 3;
144 }
145 #endif
146
147 #if ENABLE_UNIT_TEST
148
BBUNIT_DEFINE_TEST(is_prefixed_with)149 BBUNIT_DEFINE_TEST(is_prefixed_with)
150 {
151 BBUNIT_ASSERT_STREQ(" bar", is_prefixed_with("foo bar", "foo"));
152 BBUNIT_ASSERT_STREQ("bar", is_prefixed_with("foo bar", "foo "));
153 BBUNIT_ASSERT_STREQ("", is_prefixed_with("foo", "foo"));
154 BBUNIT_ASSERT_STREQ("foo", is_prefixed_with("foo", ""));
155 BBUNIT_ASSERT_STREQ("", is_prefixed_with("", ""));
156
157 BBUNIT_ASSERT_NULL(is_prefixed_with("foo", "bar foo"));
158 BBUNIT_ASSERT_NULL(is_prefixed_with("foo foo", "bar"));
159 BBUNIT_ASSERT_NULL(is_prefixed_with("", "foo"));
160
161 BBUNIT_ENDTEST;
162 }
163
BBUNIT_DEFINE_TEST(is_suffixed_with)164 BBUNIT_DEFINE_TEST(is_suffixed_with)
165 {
166 BBUNIT_ASSERT_STREQ("bar", is_suffixed_with("foo bar", "bar"));
167 BBUNIT_ASSERT_STREQ("foo", is_suffixed_with("foo", "foo"));
168 BBUNIT_ASSERT_STREQ("", is_suffixed_with("foo", ""));
169 BBUNIT_ASSERT_STREQ("", is_suffixed_with("", ""));
170 BBUNIT_ASSERT_STREQ("foo", is_suffixed_with("barfoofoo", "foo"));
171
172 BBUNIT_ASSERT_NULL(is_suffixed_with("foo", "bar foo"));
173 BBUNIT_ASSERT_NULL(is_suffixed_with("foo foo", "bar"));
174 BBUNIT_ASSERT_NULL(is_suffixed_with("", "foo"));
175
176 BBUNIT_ENDTEST;
177 }
178
179 #endif /* ENABLE_UNIT_TEST */
180