xref: /linux/tools/perf/util/path.c (revision d257f9bf06129613de539ea71ecea60848b662cd)
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 #include "path.h"
15 #include <linux/kernel.h>
16 #include <limits.h>
17 #include <stdio.h>
18 #include <sys/types.h>
19 #include <sys/stat.h>
20 #include <unistd.h>
21 
22 static char bad_path[] = "/bad-path/";
23 /*
24  * One hack:
25  */
26 static char *get_pathname(void)
27 {
28 	static char pathname_array[4][PATH_MAX];
29 	static int idx;
30 
31 	return pathname_array[3 & ++idx];
32 }
33 
34 static char *cleanup_path(char *path)
35 {
36 	/* Clean it up */
37 	if (!memcmp(path, "./", 2)) {
38 		path += 2;
39 		while (*path == '/')
40 			path++;
41 	}
42 	return path;
43 }
44 
45 char *mkpath(const char *fmt, ...)
46 {
47 	va_list args;
48 	unsigned len;
49 	char *pathname = get_pathname();
50 
51 	va_start(args, fmt);
52 	len = vsnprintf(pathname, PATH_MAX, fmt, args);
53 	va_end(args);
54 	if (len >= PATH_MAX)
55 		return bad_path;
56 	return cleanup_path(pathname);
57 }
58 
59 int path__join(char *bf, size_t size, const char *path1, const char *path2)
60 {
61 	return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
62 }
63 
64 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
65 {
66 	return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
67 			 path2, path2[0] ? "/" : "", path3);
68 }
69 
70 bool is_regular_file(const char *file)
71 {
72 	struct stat st;
73 
74 	if (stat(file, &st))
75 		return false;
76 
77 	return S_ISREG(st.st_mode);
78 }
79