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 "path.h"
15 #include "cache.h"
16 #include <linux/kernel.h>
17 #include <limits.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <dirent.h>
23 #include <unistd.h>
24
25 static char bad_path[] = "/bad-path/";
26 /*
27 * One hack:
28 */
get_pathname(void)29 static char *get_pathname(void)
30 {
31 static char pathname_array[4][PATH_MAX];
32 static int idx;
33
34 return pathname_array[3 & ++idx];
35 }
36
cleanup_path(char * path)37 static char *cleanup_path(char *path)
38 {
39 /* Clean it up */
40 if (!memcmp(path, "./", 2)) {
41 path += 2;
42 while (*path == '/')
43 path++;
44 }
45 return path;
46 }
47
mkpath(const char * fmt,...)48 char *mkpath(const char *fmt, ...)
49 {
50 va_list args;
51 unsigned len;
52 char *pathname = get_pathname();
53
54 va_start(args, fmt);
55 len = vsnprintf(pathname, PATH_MAX, fmt, args);
56 va_end(args);
57 if (len >= PATH_MAX)
58 return bad_path;
59 return cleanup_path(pathname);
60 }
61
path__join(char * bf,size_t size,const char * path1,const char * path2)62 int path__join(char *bf, size_t size, const char *path1, const char *path2)
63 {
64 return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
65 }
66
path__join3(char * bf,size_t size,const char * path1,const char * path2,const char * path3)67 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
68 {
69 return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
70 path2, path2[0] ? "/" : "", path3);
71 }
72
is_regular_file(const char * file)73 bool is_regular_file(const char *file)
74 {
75 struct stat st;
76
77 if (stat(file, &st))
78 return false;
79
80 return S_ISREG(st.st_mode);
81 }
82
83 /* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
is_directory(const char * base_path,const struct dirent * dent)84 bool is_directory(const char *base_path, const struct dirent *dent)
85 {
86 char path[PATH_MAX];
87 struct stat st;
88
89 snprintf(path, sizeof(path), "%s/%s", base_path, dent->d_name);
90 if (stat(path, &st))
91 return false;
92
93 return S_ISDIR(st.st_mode);
94 }
95
is_executable_file(const char * base_path,const struct dirent * dent)96 bool is_executable_file(const char *base_path, const struct dirent *dent)
97 {
98 char path[PATH_MAX];
99 struct stat st;
100
101 snprintf(path, sizeof(path), "%s/%s", base_path, dent->d_name);
102 if (stat(path, &st))
103 return false;
104
105 return !S_ISDIR(st.st_mode) && (st.st_mode & S_IXUSR);
106 }
107