blob: 2f51237a33301fadb9523707c4a23ea4dbf44710
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 */ |
172 |