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 static 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 33 static 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 44 char *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 58 char *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 */ 80 static 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 */ 92 char *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 } 114