Linux kernel mirror (for testing)
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linux
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}