1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Helper function for splitting a string into an argv-like array. |
4 | */ |
5 | |
6 | #include <stdlib.h> |
7 | #include <linux/kernel.h> |
8 | #include <linux/ctype.h> |
9 | #include <linux/string.h> |
10 | |
11 | static const char *skip_arg(const char *cp) |
12 | { |
13 | while (*cp && !isspace(*cp)) |
14 | cp++; |
15 | |
16 | return cp; |
17 | } |
18 | |
19 | static int count_argc(const char *str) |
20 | { |
21 | int count = 0; |
22 | |
23 | while (*str) { |
24 | str = skip_spaces(str); |
25 | if (*str) { |
26 | count++; |
27 | str = skip_arg(cp: str); |
28 | } |
29 | } |
30 | |
31 | return count; |
32 | } |
33 | |
34 | /** |
35 | * argv_free - free an argv |
36 | * @argv - the argument vector to be freed |
37 | * |
38 | * Frees an argv and the strings it points to. |
39 | */ |
40 | void argv_free(char **argv) |
41 | { |
42 | char **p; |
43 | for (p = argv; *p; p++) { |
44 | free(*p); |
45 | *p = NULL; |
46 | } |
47 | |
48 | free(argv); |
49 | } |
50 | |
51 | /** |
52 | * argv_split - split a string at whitespace, returning an argv |
53 | * @str: the string to be split |
54 | * @argcp: returned argument count |
55 | * |
56 | * Returns an array of pointers to strings which are split out from |
57 | * @str. This is performed by strictly splitting on white-space; no |
58 | * quote processing is performed. Multiple whitespace characters are |
59 | * considered to be a single argument separator. The returned array |
60 | * is always NULL-terminated. Returns NULL on memory allocation |
61 | * failure. |
62 | */ |
63 | char **argv_split(const char *str, int *argcp) |
64 | { |
65 | int argc = count_argc(str); |
66 | char **argv = calloc(argc + 1, sizeof(*argv)); |
67 | char **argvp; |
68 | |
69 | if (argv == NULL) |
70 | goto out; |
71 | |
72 | if (argcp) |
73 | *argcp = argc; |
74 | |
75 | argvp = argv; |
76 | |
77 | while (*str) { |
78 | str = skip_spaces(str); |
79 | |
80 | if (*str) { |
81 | const char *p = str; |
82 | char *t; |
83 | |
84 | str = skip_arg(cp: str); |
85 | |
86 | t = strndup(p, str-p); |
87 | if (t == NULL) |
88 | goto fail; |
89 | *argvp++ = t; |
90 | } |
91 | } |
92 | *argvp = NULL; |
93 | |
94 | out: |
95 | return argv; |
96 | |
97 | fail: |
98 | argv_free(argv); |
99 | return NULL; |
100 | } |
101 | |