Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/*
2 * Helper function for splitting a string into an argv-like array.
3 */
4
5#include <linux/kernel.h>
6#include <linux/ctype.h>
7#include <linux/bug.h>
8
9static const char *skip_sep(const char *cp)
10{
11 while (*cp && isspace(*cp))
12 cp++;
13
14 return cp;
15}
16
17static const char *skip_arg(const char *cp)
18{
19 while (*cp && !isspace(*cp))
20 cp++;
21
22 return cp;
23}
24
25static int count_argc(const char *str)
26{
27 int count = 0;
28
29 while (*str) {
30 str = skip_sep(str);
31 if (*str) {
32 count++;
33 str = skip_arg(str);
34 }
35 }
36
37 return count;
38}
39
40/**
41 * argv_free - free an argv
42 * @argv - the argument vector to be freed
43 *
44 * Frees an argv and the strings it points to.
45 */
46void argv_free(char **argv)
47{
48 char **p;
49 for (p = argv; *p; p++)
50 kfree(*p);
51
52 kfree(argv);
53}
54EXPORT_SYMBOL(argv_free);
55
56/**
57 * argv_split - split a string at whitespace, returning an argv
58 * @gfp: the GFP mask used to allocate memory
59 * @str: the string to be split
60 * @argcp: returned argument count
61 *
62 * Returns an array of pointers to strings which are split out from
63 * @str. This is performed by strictly splitting on white-space; no
64 * quote processing is performed. Multiple whitespace characters are
65 * considered to be a single argument separator. The returned array
66 * is always NULL-terminated. Returns NULL on memory allocation
67 * failure.
68 */
69char **argv_split(gfp_t gfp, const char *str, int *argcp)
70{
71 int argc = count_argc(str);
72 char **argv = kzalloc(sizeof(*argv) * (argc+1), gfp);
73 char **argvp;
74
75 if (argv == NULL)
76 goto out;
77
78 *argcp = argc;
79 argvp = argv;
80
81 while (*str) {
82 str = skip_sep(str);
83
84 if (*str) {
85 const char *p = str;
86 char *t;
87
88 str = skip_arg(str);
89
90 t = kstrndup(p, str-p, gfp);
91 if (t == NULL)
92 goto fail;
93 *argvp++ = t;
94 }
95 }
96 *argvp = NULL;
97
98 out:
99 return argv;
100
101 fail:
102 argv_free(argv);
103 return NULL;
104}
105EXPORT_SYMBOL(argv_split);