| 1 | |
| 2 | |
| 3 | * linux/lib/cmdline.c
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| 4 | * Helper functions generally used for parsing kernel command line
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| 5 | * and module options.
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| 6 | *
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| 7 | * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
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| 8 | *
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| 9 | * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
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| 10 |
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| 11 |
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| 12 | #include <linux/export.h>
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| 13 | #include <linux/kernel.h>
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| 14 | #include <linux/string.h>
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| 15 | #include <linux/ctype.h>
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| 16 |
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| 17 | |
| 18 | * If a hyphen was found in get_option, this will handle the
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| 19 | * range of numbers, M-N. This will expand the range and insert
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| 20 | * the values[M, M+1, ..., N] into the ints array in get_options.
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| 21 |
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| 22 |
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| 23 | static int get_range(char **str, int *pint, int n)
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| 24 | {
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| 25 | int x, inc_counter, upper_range;
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| 26 |
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| 27 | (*str)++;
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| 28 | upper_range = simple_strtol((*str), NULL, 0);
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| 29 | inc_counter = upper_range - *pint;
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| 30 | for (x = *pint; n && x < upper_range; x++, n--)
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| 31 | *pint++ = x;
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| 32 | return inc_counter;
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| 33 | }
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| 34 |
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| 35 | |
| 36 | * get_option - Parse integer from an option string
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| 37 | * @str: option string
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| 38 | * @pint: (optional output) integer value parsed from @str
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| 39 | *
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| 40 | * Read an int from an option string; if available accept a subsequent
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| 41 | * comma as well.
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| 42 | *
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| 43 | * When @pint is NULL the function can be used as a validator of
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| 44 | * the current option in the string.
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| 45 | *
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| 46 | * Return values:
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| 47 | * 0 - no int in string
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| 48 | * 1 - int found, no subsequent comma
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| 49 | * 2 - int found including a subsequent comma
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| 50 | * 3 - hyphen found to denote a range
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| 51 | *
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| 52 | * Leading hyphen without integer is no integer case, but we consume it
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| 53 | * for the sake of simplification.
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| 54 |
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| 55 |
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| 56 | int get_option(char **str, int *pint)
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| 57 | {
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| 58 | char *cur = *str;
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| 59 | int value;
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| 60 |
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| 61 | if (!cur || !(*cur))
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| 62 | return 0;
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| 63 | if (*cur == '-')
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| 64 | value = -simple_strtoull(++cur, str, 0);
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| 65 | else
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| 66 | value = simple_strtoull(cur, str, 0);
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| 67 | if (pint)
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| 68 | *pint = value;
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| 69 | if (cur == *str)
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| 70 | return 0;
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| 71 | if (**str == ',') {
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| 72 | (*str)++;
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| 73 | return 2;
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| 74 | }
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| 75 | if (**str == '-')
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| 76 | return 3;
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| 77 |
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| 78 | return 1;
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| 79 | }
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| 80 | EXPORT_SYMBOL(get_option);
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| 81 |
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| 82 | |
| 83 | * get_options - Parse a string into a list of integers
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| 84 | * @str: String to be parsed
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| 85 | * @nints: size of integer array
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| 86 | * @ints: integer array (must have room for at least one element)
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| 87 | *
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| 88 | * This function parses a string containing a comma-separated
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| 89 | * list of integers, a hyphen-separated range of _positive_ integers,
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| 90 | * or a combination of both. The parse halts when the array is
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| 91 | * full, or when no more numbers can be retrieved from the
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| 92 | * string.
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| 93 | *
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| 94 | * When @nints is 0, the function just validates the given @str and
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| 95 | * returns the amount of parseable integers as described below.
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| 96 | *
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| 97 | * Returns:
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| 98 | *
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| 99 | * The first element is filled by the number of collected integers
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| 100 | * in the range. The rest is what was parsed from the @str.
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| 101 | *
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| 102 | * Return value is the character in the string which caused
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| 103 | * the parse to end (typically a null terminator, if @str is
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| 104 | * completely parseable).
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| 105 |
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| 106 |
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| 107 | char *get_options(const char *str, int nints, int *ints)
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| 108 | {
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| 109 | bool validate = (nints == 0);
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| 110 | int res, i = 1;
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| 111 |
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| 112 | while (i < nints || validate) {
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| 113 | int *pint = validate ? ints : ints + i;
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| 114 |
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| 115 | res = get_option((char **)&str, pint);
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| 116 | if (res == 0)
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| 117 | break;
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| 118 | if (res == 3) {
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| 119 | int n = validate ? 0 : nints - i;
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| 120 | int range_nums;
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| 121 |
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| 122 | range_nums = get_range((char **)&str, pint, n);
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| 123 | if (range_nums < 0)
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| 124 | break;
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| 125 | |
| 126 | * Decrement the result by one to leave out the
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| 127 | * last number in the range. The next iteration
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| 128 | * will handle the upper number in the range
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| 129 |
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| 130 | i += (range_nums - 1);
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| 131 | }
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| 132 | i++;
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| 133 | if (res == 1)
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| 134 | break;
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| 135 | }
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| 136 | ints[0] = i - 1;
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| 137 | return (char *)str;
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| 138 | }
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| 139 | EXPORT_SYMBOL(get_options);
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| 140 |
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| 141 | |
| 142 | * memparse - parse a string with mem suffixes into a number
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| 143 | * @ptr: Where parse begins
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| 144 | * @retptr: (output) Optional pointer to next char after parse completes
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| 145 | *
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| 146 | * Parses a string into a number. The number stored at @ptr is
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| 147 | * potentially suffixed with K, M, G, T, P, E.
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| 148 |
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| 149 |
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| 150 | unsigned long long memparse(const char *ptr, char **retptr)
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| 151 | {
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| 152 | char *endptr;
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| 153 |
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| 154 | unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
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| 155 |
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| 156 | switch (*endptr) {
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| 157 | case 'E':
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| 158 | case 'e':
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| 159 | ret <<= 10;
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| 160 | fallthrough;
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| 161 | case 'P':
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| 162 | case 'p':
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| 163 | ret <<= 10;
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| 164 | fallthrough;
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| 165 | case 'T':
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| 166 | case 't':
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| 167 | ret <<= 10;
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| 168 | fallthrough;
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| 169 | case 'G':
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| 170 | case 'g':
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| 171 | ret <<= 10;
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| 172 | fallthrough;
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| 173 | case 'M':
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| 174 | case 'm':
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| 175 | ret <<= 10;
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| 176 | fallthrough;
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| 177 | case 'K':
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| 178 | case 'k':
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| 179 | ret <<= 10;
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| 180 | endptr++;
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| 181 | fallthrough;
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| 182 | default:
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| 183 | break;
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| 184 | }
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| 185 |
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| 186 | if (retptr)
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| 187 | *retptr = endptr;
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| 188 |
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| 189 | return ret;
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| 190 | }
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| 191 | EXPORT_SYMBOL(memparse);
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| 192 |
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| 193 | |
| 194 | * parse_option_str - Parse a string and check an option is set or not
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| 195 | * @str: String to be parsed
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| 196 | * @option: option name
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| 197 | *
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| 198 | * This function parses a string containing a comma-separated list of
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| 199 | * strings like a=b,c.
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| 200 | *
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| 201 | * Return true if there's such option in the string, or return false.
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| 202 |
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| 203 | bool parse_option_str(const char *str, const char *option)
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| 204 | {
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| 205 | while (*str) {
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| 206 | if (!strncmp(str, option, strlen(option))) {
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| 207 | str += strlen(option);
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| 208 | if (!*str || *str == ',')
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| 209 | return true;
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| 210 | }
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| 211 |
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| 212 | while (*str && *str != ',')
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| 213 | str++;
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| 214 |
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| 215 | if (*str == ',')
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| 216 | str++;
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| 217 | }
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| 218 |
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| 219 | return false;
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| 220 | }
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| 221 |
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| 222 | |
| 223 | * Parse a string to get a param value pair.
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| 224 | * You can use " around spaces, but can't escape ".
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| 225 | * Hyphens and underscores equivalent in parameter names.
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| 226 |
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| 227 | char *next_arg(char *args, char **param, char **val)
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| 228 | {
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| 229 | unsigned int i, equals = 0;
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| 230 | int in_quote = 0, quoted = 0;
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| 231 |
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| 232 | if (*args == '"') {
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| 233 | args++;
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| 234 | in_quote = 1;
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| 235 | quoted = 1;
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| 236 | }
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| 237 |
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| 238 | for (i = 0; args[i]; i++) {
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| 239 | if (isspace(args[i]) && !in_quote)
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| 240 | break;
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| 241 | if (equals == 0) {
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| 242 | if (args[i] == '=')
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| 243 | equals = i;
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| 244 | }
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| 245 | if (args[i] == '"')
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| 246 | in_quote = !in_quote;
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| 247 | }
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| 248 |
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| 249 | *param = args;
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| 250 | if (!equals)
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| 251 | *val = NULL;
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| 252 | else {
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| 253 | args[equals] = '\0';
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| 254 | *val = args + equals + 1;
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| 255 |
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| 256 |
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| 257 | if (**val == '"') {
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| 258 | (*val)++;
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| 259 | if (args[i-1] == '"')
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| 260 | args[i-1] = '\0';
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| 261 | }
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| 262 | }
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| 263 | if (quoted && args[i-1] == '"')
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| 264 | args[i-1] = '\0';
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| 265 |
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| 266 | if (args[i]) {
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| 267 | args[i] = '\0';
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| 268 | args += i + 1;
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| 269 | } else
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| 270 | args += i;
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| 271 |
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| 272 |
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| 273 | return skip_spaces(args);
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| 274 | }
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| 275 | EXPORT_SYMBOL(next_arg);
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