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 "cache.h" 15 #include "path.h" 16 #include <linux/kernel.h> 17 #include <limits.h> 18 #include <stdio.h> 19 #include <sys/types.h> 20 #include <sys/stat.h> 21 #include <dirent.h> 22 #include <unistd.h> 23 24 static char bad_path[] = "/bad-path/"; 25 /* 26 * One hack: 27 */ 28 static char *get_pathname(void) 29 { 30 static char pathname_array[4][PATH_MAX]; 31 static int idx; 32 33 return pathname_array[3 & ++idx]; 34 } 35 36 static char *cleanup_path(char *path) 37 { 38 /* Clean it up */ 39 if (!memcmp(path, "./", 2)) { 40 path += 2; 41 while (*path == '/') 42 path++; 43 } 44 return path; 45 } 46 47 char *mkpath(const char *fmt, ...) 48 { 49 va_list args; 50 unsigned len; 51 char *pathname = get_pathname(); 52 53 va_start(args, fmt); 54 len = vsnprintf(pathname, PATH_MAX, fmt, args); 55 va_end(args); 56 if (len >= PATH_MAX) 57 return bad_path; 58 return cleanup_path(pathname); 59 } 60 61 int path__join(char *bf, size_t size, const char *path1, const char *path2) 62 { 63 return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2); 64 } 65 66 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3) 67 { 68 return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "", 69 path2, path2[0] ? "/" : "", path3); 70 } 71 72 bool is_regular_file(const char *file) 73 { 74 struct stat st; 75 76 if (stat(file, &st)) 77 return false; 78 79 return S_ISREG(st.st_mode); 80 } 81 82 /* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */ 83 bool is_directory(const char *base_path, const struct dirent *dent) 84 { 85 char path[PATH_MAX]; 86 struct stat st; 87 88 sprintf(path, "%s/%s", base_path, dent->d_name); 89 if (stat(path, &st)) 90 return false; 91 92 return S_ISDIR(st.st_mode); 93 } 94