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
15 static char bad_path[] = "/bad-path/";
16 /*
17 * Two hacks:
18 */
19
get_perf_dir(void)20 static const char *get_perf_dir(void)
21 {
22 return ".";
23 }
24
25 #ifdef NO_STRLCPY
strlcpy(char * dest,const char * src,size_t size)26 size_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
get_pathname(void)39 static 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
cleanup_path(char * path)47 static 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
perf_vsnpath(char * buf,size_t n,const char * fmt,va_list args)58 static 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);
73 bad:
74 strlcpy(buf, bad_path, n);
75 return buf;
76 }
77
perf_pathdup(const char * fmt,...)78 char *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
mkpath(const char * fmt,...)88 char *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
perf_path(const char * fmt,...)102 char *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 */
chomp_trailing_dir_sep(const char * path,int len)124 static 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 */
strip_path_suffix(const char * path,const char * suffix)136 char *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 }
158