Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * I'm tired of doing "vsnprintf()" etc just to open a
3 * file, so here's a "return static buffer with printf"
4 * interface for paths.
5 *
6 * It's obviously not thread-safe. Sue me. But it's quite
7 * useful for doing things like
8 *
9 * f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
10 *
11 * which is what it's designed for.
12 */
13#include "cache.h"
14
15static char bad_path[] = "/bad-path/";
16/*
17 * Two hacks:
18 */
19
20static const char *get_perf_dir(void)
21{
22 return ".";
23}
24
25static char *get_pathname(void)
26{
27 static char pathname_array[4][PATH_MAX];
28 static int idx;
29
30 return pathname_array[3 & ++idx];
31}
32
33static char *cleanup_path(char *path)
34{
35 /* Clean it up */
36 if (!memcmp(path, "./", 2)) {
37 path += 2;
38 while (*path == '/')
39 path++;
40 }
41 return path;
42}
43
44char *mkpath(const char *fmt, ...)
45{
46 va_list args;
47 unsigned len;
48 char *pathname = get_pathname();
49
50 va_start(args, fmt);
51 len = vsnprintf(pathname, PATH_MAX, fmt, args);
52 va_end(args);
53 if (len >= PATH_MAX)
54 return bad_path;
55 return cleanup_path(pathname);
56}
57
58char *perf_path(const char *fmt, ...)
59{
60 const char *perf_dir = get_perf_dir();
61 char *pathname = get_pathname();
62 va_list args;
63 unsigned len;
64
65 len = strlen(perf_dir);
66 if (len > PATH_MAX-100)
67 return bad_path;
68 memcpy(pathname, perf_dir, len);
69 if (len && perf_dir[len-1] != '/')
70 pathname[len++] = '/';
71 va_start(args, fmt);
72 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
73 va_end(args);
74 if (len >= PATH_MAX)
75 return bad_path;
76 return cleanup_path(pathname);
77}
78
79/* strip arbitrary amount of directory separators at end of path */
80static inline int chomp_trailing_dir_sep(const char *path, int len)
81{
82 while (len && is_dir_sep(path[len - 1]))
83 len--;
84 return len;
85}
86
87/*
88 * If path ends with suffix (complete path components), returns the
89 * part before suffix (sans trailing directory separators).
90 * Otherwise returns NULL.
91 */
92char *strip_path_suffix(const char *path, const char *suffix)
93{
94 int path_len = strlen(path), suffix_len = strlen(suffix);
95
96 while (suffix_len) {
97 if (!path_len)
98 return NULL;
99
100 if (is_dir_sep(path[path_len - 1])) {
101 if (!is_dir_sep(suffix[suffix_len - 1]))
102 return NULL;
103 path_len = chomp_trailing_dir_sep(path, path_len);
104 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
105 }
106 else if (path[--path_len] != suffix[--suffix_len])
107 return NULL;
108 }
109
110 if (path_len && !is_dir_sep(path[path_len - 1]))
111 return NULL;
112 return strndup(path, chomp_trailing_dir_sep(path, path_len));
113}