Commit | Line | Data |
---|---|---|
9c10548c ACM |
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(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(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 | } |