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
25static char bad_path[] = "/bad-path/";
26/*
27 * One hack:
28 */
 
 
 
 
 
 
29static 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
37static 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
48char *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
62int 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
67int 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
73bool 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 */
84bool is_directory(const char *base_path, const struct dirent *dent)
 
 
 
 
85{
86	char path[PATH_MAX];
87	struct stat st;
88
89	sprintf(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}

 
  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}