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 25 static char bad_path[] = "/bad-path/"; 26 /* 27 * One hack: 28 */ 29 static 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 37 static 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 48 char *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 62 int 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 67 int 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 73 bool 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 */ 84 bool 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 } 95