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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * I'm tired of doing "vsnprintf()" etc just to open a
4 * file, so here's a "return static buffer with printf"
5 * interface for paths.
6 *
7 * It's obviously not thread-safe. Sue me. But it's quite
8 * useful for doing things like
9 *
10 * f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
11 *
12 * which is what it's designed for.
13 */
14#include "cache.h"
15#include "path.h"
16#include <linux/kernel.h>
17#include <limits.h>
18#include <stdio.h>
19#include <sys/types.h>
20#include <sys/stat.h>
21#include <dirent.h>
22#include <unistd.h>
23
24static char bad_path[] = "/bad-path/";
25/*
26 * One hack:
27 */
28static char *get_pathname(void)
29{
30 static char pathname_array[4][PATH_MAX];
31 static int idx;
32
33 return pathname_array[3 & ++idx];
34}
35
36static char *cleanup_path(char *path)
37{
38 /* Clean it up */
39 if (!memcmp(path, "./", 2)) {
40 path += 2;
41 while (*path == '/')
42 path++;
43 }
44 return path;
45}
46
47char *mkpath(const char *fmt, ...)
48{
49 va_list args;
50 unsigned len;
51 char *pathname = get_pathname();
52
53 va_start(args, fmt);
54 len = vsnprintf(pathname, PATH_MAX, fmt, args);
55 va_end(args);
56 if (len >= PATH_MAX)
57 return bad_path;
58 return cleanup_path(pathname);
59}
60
61int path__join(char *bf, size_t size, const char *path1, const char *path2)
62{
63 return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
64}
65
66int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
67{
68 return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
69 path2, path2[0] ? "/" : "", path3);
70}
71
72bool is_regular_file(const char *file)
73{
74 struct stat st;
75
76 if (stat(file, &st))
77 return false;
78
79 return S_ISREG(st.st_mode);
80}
81
82/* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
83bool is_directory(const char *base_path, const struct dirent *dent)
84{
85 char path[PATH_MAX];
86 struct stat st;
87
88 sprintf(path, "%s/%s", base_path, dent->d_name);
89 if (stat(path, &st))
90 return false;
91
92 return S_ISDIR(st.st_mode);
93}
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
25#ifdef NO_STRLCPY
26size_t strlcpy(char *dest, const char *src, size_t size)
27{
28 size_t ret = strlen(src);
29
30 if (size) {
31 size_t len = (ret >= size) ? size - 1 : ret;
32 memcpy(dest, src, len);
33 dest[len] = '\0';
34 }
35 return ret;
36}
37#endif
38
39static char *get_pathname(void)
40{
41 static char pathname_array[4][PATH_MAX];
42 static int idx;
43
44 return pathname_array[3 & ++idx];
45}
46
47static char *cleanup_path(char *path)
48{
49 /* Clean it up */
50 if (!memcmp(path, "./", 2)) {
51 path += 2;
52 while (*path == '/')
53 path++;
54 }
55 return path;
56}
57
58static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
59{
60 const char *perf_dir = get_perf_dir();
61 size_t len;
62
63 len = strlen(perf_dir);
64 if (n < len + 1)
65 goto bad;
66 memcpy(buf, perf_dir, len);
67 if (len && !is_dir_sep(perf_dir[len-1]))
68 buf[len++] = '/';
69 len += vsnprintf(buf + len, n - len, fmt, args);
70 if (len >= n)
71 goto bad;
72 return cleanup_path(buf);
73bad:
74 strlcpy(buf, bad_path, n);
75 return buf;
76}
77
78char *perf_pathdup(const char *fmt, ...)
79{
80 char path[PATH_MAX];
81 va_list args;
82 va_start(args, fmt);
83 (void)perf_vsnpath(path, sizeof(path), fmt, args);
84 va_end(args);
85 return xstrdup(path);
86}
87
88char *mkpath(const char *fmt, ...)
89{
90 va_list args;
91 unsigned len;
92 char *pathname = get_pathname();
93
94 va_start(args, fmt);
95 len = vsnprintf(pathname, PATH_MAX, fmt, args);
96 va_end(args);
97 if (len >= PATH_MAX)
98 return bad_path;
99 return cleanup_path(pathname);
100}
101
102char *perf_path(const char *fmt, ...)
103{
104 const char *perf_dir = get_perf_dir();
105 char *pathname = get_pathname();
106 va_list args;
107 unsigned len;
108
109 len = strlen(perf_dir);
110 if (len > PATH_MAX-100)
111 return bad_path;
112 memcpy(pathname, perf_dir, len);
113 if (len && perf_dir[len-1] != '/')
114 pathname[len++] = '/';
115 va_start(args, fmt);
116 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
117 va_end(args);
118 if (len >= PATH_MAX)
119 return bad_path;
120 return cleanup_path(pathname);
121}
122
123/* strip arbitrary amount of directory separators at end of path */
124static inline int chomp_trailing_dir_sep(const char *path, int len)
125{
126 while (len && is_dir_sep(path[len - 1]))
127 len--;
128 return len;
129}
130
131/*
132 * If path ends with suffix (complete path components), returns the
133 * part before suffix (sans trailing directory separators).
134 * Otherwise returns NULL.
135 */
136char *strip_path_suffix(const char *path, const char *suffix)
137{
138 int path_len = strlen(path), suffix_len = strlen(suffix);
139
140 while (suffix_len) {
141 if (!path_len)
142 return NULL;
143
144 if (is_dir_sep(path[path_len - 1])) {
145 if (!is_dir_sep(suffix[suffix_len - 1]))
146 return NULL;
147 path_len = chomp_trailing_dir_sep(path, path_len);
148 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
149 }
150 else if (path[--path_len] != suffix[--suffix_len])
151 return NULL;
152 }
153
154 if (path_len && !is_dir_sep(path[path_len - 1]))
155 return NULL;
156 return strndup(path, chomp_trailing_dir_sep(path, path_len));
157}