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 20 static const char *get_perf_dir(void) 21 { 22 return "."; 23 } 24 25 #ifdef NO_STRLCPY 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 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 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 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 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 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 } 101 102 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 */ 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 */ 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